Upload
others
View
18
Download
0
Embed Size (px)
Citation preview
VISVESVARAYA TECHNOLOGICAL UNIVERSITY
“Jnana Sangama”, Belagavi, Karnataka, India – 590 018
PROJECT REPORT
ON
“DELINEATION OF WATERSHED AND ESTIMATION OF
DISCHARGE OF RIVER SHIMSHA USING GIS”
Submitted in Partial fulfilment of the requirement for the award of
BACHELOR OF ENGINEERING
IN
CIVIL ENGINEERING
Submitted by
BHARATA H S 1CG12CV006
DARSHAN K H 1CG12CV011
PAVAN S 1CG13CV412
SPOORTHY SADASHIV SHANUBHOG 1CG12CV043
Sponsored by,
KARNATAKA STATE COUNCIL FOR SCIENCE AND TECHNOLOGY
Indian Institute of Science, Bengaluru - 560012
CHANNABASAVESHWARA INSTITUTE OF TECHNOLOGY
(An ISO 9001:2008 Certified Institution)
(Affiliated to Visvesvaraya Technological University, Belagavi & Recognized by AICTE, New Delhi)
N.H.206 (B.H. Road), Gubbi, Tumakuru, Karnataka – 572 216
DEPARTMENT OF CIVIL ENGINEERING
2015 – 2016
Under the guidance of,
Mr. MANJUNATHA M KATTI M.Tech.
Assistant Professor
Dept. of Civil Engineering
CIT, Gubbi.
Dedicated for a
healthy, prosperous
and green environment
and for the welfare of
Tumakuru District
OUR TRIBUTE TO THE PRE-EMINENT
ENGINEER OF INDIA
BHARAT RATNA
SIR M VISVESVARAYA
1860 - 1962
Image Source: http://guruprasad.net/wp-content/uploads/2013/09/sir-mv.jpg
i
ABSTRACT
Geographical Information System (GIS) is an effective tool to perform many operations
such as digitization, delineation of streams in a watershed. This tool can be efficiently used
to carry out hydrological analysis and hence used for sustainable watershed management
projects. In the process, the watershed of River Shimsha was delineated and discharge
estimation was carried out using toposheets from Survey of India (Scale 1:50,000) and
satellite based remote sensing digital elevation model (DEM). GIS tool (QGIS) was used
to perform morphometric analysis for the above to derive stream characteristics and stream
orders. Using Strange’s table, the yield of runoff from the catchment was estimated. The
study revealed that a minimum of about 3.3 TMC or an average of 4.94 TMC of water can
be accumulated annually out of the Shimsha drainage basin. This is a considerable quantity
of water which calls for a sustainable water resource management.
ii
ACKNOWLEDGEMENTS
The satisfaction accompanying the successful completion of any task would be
incomplete without mention of the people who made it possible by their support and
guidance which had been a constant source of encouragement that crowned our efforts with
success.
First and foremost, we have to thank our parents and family for their love and moral
support throughout our lives. They have equipped us with everything we need.
At the outset we express our most sincere thanks to our college,
“CHANNABASAVESHWARA INSTITUTE OF TECHNOLOGY”, for providing us
an opportunity to pursue the degree course in Civil Engineering thus help in shaping our
carrier.
We take this opportunity to express our sincere thanks and deep sense of gratitude
to our beloved Director and Principal, Dr. Suresh Kumar D. S, for facilitating us with all
the required infrastructure and resources during our stay with CIT.
Our special gratitude to Dr. Sudhi Kumar G. S, Head of Dept., Civil Engineering.,
CIT, Gubbi for his constant guidance, encouragement, appreciation and cooperation
throughout the course.
We express our sincerest thanks to our project coordinator and guide, Mr.
Manjunatha M Katti, Assistant Professor, Dept. of Civil Engineering CIT, Gubbi for his
guidance and suggestions in carrying out this work.
We would like to express grateful thanks to all the teaching staff of Department of
Civil Engineering for the guidance and encouragement throughout the course.
We also would like to extend our humble thanks to non-teaching staff of
Department of Civil Engineering for their cooperation.
Also we acknowledge, Karnataka State Council for Science and Technology
(KSCST) for sponsoring this project and a platform to present this project in the 39th series
of Student Project Programme (SPP).
We sincerely thank Mr. H. B. Mallesh, Assistant Executive Engineer, Hemavathi
Neeravari Nigama, Tumakuru for his timely assistance and guidance.
iii
It is an honour and privilege to convey our heart-felt gratitude for Dr. Sudhira H.S,
Director, Gubbi Labs, Gubbi for his time, assistance, guidance and generous support in the
successful completion of the project. He helped us throughout our project by inspiring and
encouraging us with his suggestions.
Our humble thanks to everyone at various organizations and departments who have
cooperated and supported us by providing the required data for this work.
Mr. Chikkasubbiaha, Joint Director, ARC and Mr. Vasanth, Directorate of
Economics and Statistics, Govt. of Karnataka, M S building, Bengaluru
Mr. Rajanna, District Statistical Officer, DC office, Tumakuru and Mrs.
Chethana B, Statistical Inspector, District Statistical Department, DC
Office, Tumakuru
Mr. Sethuramsingh, AEE, Sira and to Mrs. Suchitra, Assistant Engineer,
Minor Irrigation Department, Tumakuru
Mrs. Shylaja, Mr. Srinivasa murthy, Mr. Lingaraju, Panchayat Raj
Engineering Department, Zilla Panchayat, Tumakuru
Friends have always been our source of timely help and immeasurable support. We
thank all our friends for being with us.
Finally, we are thankful to everyone who directly or indirectly supported for the
successful completion of the project.
Thanking everyone…
Digital Cartographers:
Bharata H S
Darshan K H
Pavan S
Spoorthy Sadashiv Shanubhog
iv
CONTENTS
Abstract ............................................................................................................................. i
Acknowledgements .......................................................................................................... ii
Contents .......................................................................................................................... iv
List of Figures ................................................................................................................. vi
List of Tables ................................................................................................................. vii
List of Acronyms ........................................................................................................... vii
List of Abbreviations ................................................................................................... viii
Chapter 1 .............................................................................................................................. 1
Introduction ...................................................................................................................... 1
1.1 General ................................................................................................................... 1
1.2 Objectives .............................................................................................................. 2
1.3 Literature review .................................................................................................... 2
Chapter 2 .............................................................................................................................. 3
Hydrology and Water Resources ..................................................................................... 3
2.1 Introduction and definition .................................................................................... 3
2.2 Precipitation ........................................................................................................... 3
2.3 Runoff .................................................................................................................... 7
2.4 Stream .................................................................................................................... 7
2.5 Strahler stream order .............................................................................................. 7
2.6 Watershed .............................................................................................................. 9
2.7 Delineation of watershed ..................................................................................... 10
2.8 Rainfall-Runoff estimation .................................................................................. 11
2.9 Strange’s table ...................................................................................................... 11
2.10 Water resource management .............................................................................. 13
Chapter 3 ............................................................................................................................ 14
Geographic Information System (GIS) .......................................................................... 14
v
3.1 General ................................................................................................................. 14
3.2 Data representation in GIS ................................................................................... 15
3.3 Geo referencing .................................................................................................... 16
3.4 Digitization .......................................................................................................... 16
3.5 Remote Sensing ................................................................................................... 16
3.6 Applications of GIS ............................................................................................. 17
Chapter 4 ............................................................................................................................ 19
Study Area ..................................................................................................................... 19
4.1 About.................................................................................................................... 19
4.2 Tumakuru District ................................................................................................ 20
4.3 River Shimsha ...................................................................................................... 23
Chapter 5 ............................................................................................................................ 24
Data, Tools and Method ................................................................................................. 24
5.1 Data ...................................................................................................................... 24
5.2 Tools .................................................................................................................... 28
5.3 Methods................................................................................................................ 31
Chapter 6 ............................................................................................................................ 33
Results and Discussion .................................................................................................. 33
6.1 Results .................................................................................................................. 33
6.2 Discussion ............................................................................................................ 46
Chapter 7 ............................................................................................................................ 50
Conclusion ..................................................................................................................... 50
7.1 Scope for future work .......................................................................................... 51
References ...................................................................................................................... 52
vi
LIST OF FIGURES
Figure 2.1 Hydological Cycle .............................................................................................. 3
Figure 2.2 Diagram showing the Strahler stream order ....................................................... 8
Figure 2.3 Watershed delineation based on Strahler stream order .................................... 10
Figure 2.4 Strange's table ................................................................................................... 12
Figure 3.1 Data representation in GIS ............................................................................... 15
Figure 4.1 Location of study area ...................................................................................... 19
Figure 4.2 Study area ......................................................................................................... 20
Figure 4.3 Markonahalli Dam and Shimshapura Power Generation house ....................... 23
Figure 5.1 Toposheet of Gubbi region (57C/15) procured from Survey of India.............. 24
Figure 5.2 Toposheet indexing .......................................................................................... 25
Figure 5.3 ASTER DEM.................................................................................................... 26
Figure 5.4 Geo-located rain gauge stations of Tumakuru District ..................................... 27
Figure 5.5 QGIS logo ......................................................................................................... 28
Figure 5.6 QGIS Screen ..................................................................................................... 29
Figure 5.7 QGIS with GRASS plugin ............................................................................... 30
Figure 5.8 Method .............................................................................................................. 32
Figure 6.1 Thematic map generated from toposheet method ............................................ 34
Figure 6.2 Thematic map generated from DEM method ................................................... 35
Figure 6.3 Classification of drainage pattern ..................................................................... 39
Figure 6.4 Maidala Tank .................................................................................................... 44
Figure 6.5 6th order stream from Kadaba to Kallur tank ................................................... 44
Figure 6.6 Confluence point of the river after Kallur Tank ............................................... 44
Figure 6.7 Heat map for the interpolation of rainfall data ................................................. 45
Figure 6.8 Comparison of stream networks from toposheet and DEM methods............... 46
Figure 6.9 Graph indicating annual rainfall over watershed .............................................. 47
Figure 6.10 Present state of an inflow stream to Bheemasandra tank ............................... 48
Figure 6.11 Status of stream at Marlur tank outlet ............................................................ 48
vii
LIST OF TABLES
Table 6.1 General characteristics of the watershed ........................................................... 33
Table 6.2 Details of tanks in the watershed ....................................................................... 33
Table 6.3 Method of calculating morphometric parameters of watershed ........................ 41
Table 6.4 Morphometric parameters - toposheet method .................................................. 42
Table 6.5 Morphometric parameters - DEM method ......................................................... 43
Table 6.6 Mean annual rainfall and total inflow of water from rainfall for the watershed 45
Table 6.7 Yield of runoff computation for the catchment using mean annual rainfall based
on Strange's table ............................................................................................................... 46
LIST OF ACRONYMS
GIS Geographic Information System
DEM Digital Elevation Model
GDEM Global Digital Elevation Model
RS Remote Sensing
ASTER Advanced Spacebourne Thermal Emission and Reflection
Radiometer
SOI Survey of India
OSM OpenStreetMap
GRASS Geographic Resources Analysis Support System
NASA National Aeronautics and Space Administration
IDW Inverse Distance Weighting
SRTM Shuttle Radar Topography Mission
LiDAR Light Detection And Ranging
RADAR RAdio Detection And Ranging
viii
LIST OF ABBREVIATIONS
ABBREVIATION DESCRIPTION
cm Centimetre
ha Hectare
km Kilometre
km2 or sq. km Square kilometre
kmph Kilometre per hour
lpcd Litres per capita per day
m Metre
m3 Cubic metre
MLD Million litres per day
mm Millimetres
Sq. ft Square feet
TMC Thousand Million Cubic feet
Morphometric Parameters
C Constant channel maintenance
Dd Drainage density
Dp Drainage pattern
Ff Form factor
Fs Stream frequency
Lg Length of overland flow
Lsm Mean stream length
Lu Stream length
Rb Bifurcation ratio
Rbh Relative relief
Rc Circulatory ratio
Re Elongation ratio
Rh Relief ratio
Rl Stream length ratio
Rn Ruggedness number
T Texture ratio
U Stream order
Delineation of watershed and estimation of discharge of River Shimsha using GIS 2015 - 16
Dept. of Civil Engineering, CIT, Gubbi. 1
Chapter 1
INTRODUCTION
1.1 General
Globally the availability of fresh water is a limited resource and needs sustainable
management of this resource. Given the varied bio-climatic zones, rainfall patterns vary
and each geographic area receives a certain mean annual rainfall. However, in certain areas
with changing water demand, there is a perceived sense of inadequate rainfall over the years
and hence overall yield resulting of this precipitation.
One such case is applicable for the upstream catchment of River Shimsha that originates in
Tumakuru district of Karnataka. With changing agriculture practices and increase in
population, water demand has increased that has often pushed for the need to draw water
from other watersheds. Consequently, Tumakuru district is fed with water drawn from
River Hemavathy through human-made channels.
Further with uneven and uncertain rainfall events, there is a perceived sense of inadequate
rainfall calling for declaring the region as ‘drought’ prone despite a decent mean annual
rainfall in the catchment. In this backdrop it becomes pertinent to assess the potential yield
of runoff from rainfall in the catchment. This can be achieved by delineating the watershed
and analysing the stream network in the watershed for possible yield using appropriate
methods.
Geographical Information System (GIS) is an effective tool to perform many operations
such as digitization, delineation of streams of a watershed and carry out a variety of spatial
analysis. This tool can be efficiently used to carry out hydrological analysis and hence used
for sustainable watershed management projects.
A few studies in the recent past have attempted to study the water resource management in
Hassan district using GIS (Nungshichila Longchar et al., 2014). Similarly, morphometric
analysis combined with GIS has been applied for studying watersheds in Kunigal area of
Tumarkuru district (Abhishek Bothra et al., 2014) and Tungabhadra drainage basin in
Karnataka (Ramu et al., 2013).
Thus, this study aims to delineate the River Shimsha watershed and estimate the potential
discharge from runoff in the catchment using GIS.
Delineation of watershed and estimation of discharge of River Shimsha using GIS 2015 - 16
Dept. of Civil Engineering, CIT, Gubbi. 2
1.2 Objectives
A. To delineate the watershed of River Shimsha using toposheet and Satellite based
DEM
B. To evaluate and compare the drainage network of River Shimsha derived from
toposheet and DEM through spatial and morphometric analysis
C. To estimate the discharge from River Shimsha using hydrological methods and
spatial analysis
1.3 Literature review
(Abhishek, Anish and Vikas 2014), had carried out morphometric analysis of the drainage
basins of Kunigal Taluk in Tumakuru District using earth observation data and GIS
technique. The study on 27 sub-watersheds of the region was conducted and an elevation
model was prepared for the indication of slope and direction of flow for the terrain.
(NungshichilaLongchar, et al. 2014), had studied the various available water resources for
Hassan District and some parts of watersheds of Hemavathy, Yagachi, Votehole and
Vedavathi rivers were digitized for stream networks and tanks with the help of toposheets,
ArcGIS and total station survey to build DEM. Their study had suggested that most of
minor irrigation tanks located in Arasikere Taluk were dry and could be supplied with water
naturally from Yagachi water reservoir.
(Waikar & Nilawar, 2014), had carried out morphometric analysis and prioritization of
basin based on the integrated use of remote sensing and GIS technique for Charthana area
in the Parbhani district of Maharashtra.
(Ramu, B.Mahalingam and P.Jayashree, 2013), had conducted morphometric analysis of
Tungabhadra drainage basin based on secondary source i.e. the SRTM data.
(Sreekantha, et al. 2007), had conducted a study in Sharavathi River, central Western Ghats
to understand fish species composition with respect to landscape dynamics. The study had
used remote sensing data to show that the streams having high levels of ever greenness of
Western Ghats were richer in fish diversity. For the study land use dynamics was analysed
for the catchments and several morphometric parameters of the streams were studied using
GIS.
Delineation of watershed and estimation of discharge of River Shimsha using GIS 2015 - 16
Dept. of Civil Engineering, CIT, Gubbi. 3
Chapter 2
HYDROLOGY AND WATER RESOURCES
2.1 Introduction and definition
Hydrology may be defined as the science that deals with the origin, distribution and
circulation of water in different forms in land phases and atmosphere. Hydrology
subdivides into surface water hydrology, groundwater hydrology (hydrogeology), and
marine hydrology. Domains of hydrology include hydrometeorology, surface hydrology,
hydrogeology, drainage-basin management and water quality, where water plays the central
role.
Figure 2.1 Hydrological Cycle
2.2 Precipitation
It is the return of atmospheric moisture to the ground in solid or liquid form. Solid form-
snow, sleet, snow pellets, hailstones. Liquid form- drizzle, rainfall.
2.2.1 Types of precipitation
Precipitation, normally classified according to the factors responsible for lifting the air
mass, is of following types:
Delineation of watershed and estimation of discharge of River Shimsha using GIS 2015 - 16
Dept. of Civil Engineering, CIT, Gubbi. 4
i. Convective precipitation
In this type of precipitation, a packet of air which is warmer than the surrounding air due
to localized heating rises because of its lesser density. Air from cooler surrounding flows
to take up its place thus setting up a convective cell. The warm air continues to rise,
undergoes cooling and results in precipitation. Depending upon the moisture, thermal and
other conditions light showers to thunderstorms can be expected in convective
precipitation. Usually the extent of such rains is small, being limited to a diameter of about
10 km.
ii. Orographic precipitation
Orographic or mountain-range barriers cause lifting of the air masses. Dynamic cooling
takes place causing precipitation on the side of the blowing wind. Precipitation is normally
heavier on the windward side and lighter on leeward side. In India, heavy precipitation in
Himalayan region and at the western coast are mainly due to orographic features associated
with the south-west wind carrying sufficient quantity of moisture, while passing over
Arabian sea. Orographic precipitation gives medium to high intensity rainfall and continues
for longer duration.
iii. Cyclonic precipitation
A cyclone is a low pressure area surrounded by a larger high pressure area. When low
pressure occurs in an area, especially over large water bodies, air from the surrounding
rushes, causing the air at the low pressure zone to lift. Such a type of cyclone is called
Tropical cyclone or simply cyclone in India, Typhoon in south-east Asia and Hurricane in
America.
The system derives its energy from sea vapour and grows in size. Once the cyclone crosses
over to land, the energy source is cut-off, it becomes weak and disappears gradually. The
rainfall is normally heavy in the entire zone travelled by a cyclone. In northern hemisphere,
cyclones move in anti-clockwise direction and in southern hemisphere, they move
clockwise. Cyclonic storms move at the rate of 30 to 50 kmph and give medium to high
intensity rainfall over a larger area.
An anticyclone is an area of high pressure in which winds tend to blow spirally outward in
clockwise direction in the northern hemisphere and anti-clockwise in southern hemisphere.
Weather is normally calm and such anticyclone are not associated with rain.
Delineation of watershed and estimation of discharge of River Shimsha using GIS 2015 - 16
Dept. of Civil Engineering, CIT, Gubbi. 5
iv. Thunder storms
An air mass which moves from sea to land gets increased friction over land. These air
masses rise gradually as they move inland, giving rise to condensation and precipitation
over a limited area. Winter rainfall in southern part of India and Indonesia are mainly due
to this process. Sometimes thunder storms result in very intense rainfall.
2.2.2 Rainfall
When precipitation reaches the surface of earth in the form of droplets of water, we call it
rain. The size of drops vary from 0.5 mm to 6 mm as drops larger than this size are found
to breakup during their fall in the air. Rain is considered as light if intensity of rainfall is
up to 2.5 mm/hour, moderate from 2.5 to 7.5 mm/hour and heavy over 7.5 mm/hour.
Amount and quantity of rainfall
The amount of rainfall is usually given as a depth over a specified area, assuming that all
the rainfall accumulates over the surface and the unit for measuring amount of rainfall is
cm. The volume of rainfall = Area x Depth of Rainfall (m3). The amount of rainfall
occurring is measured with the help of rain gauges.
Intensity of rainfall
This is usually average of rainfall rate of rainfall during the special periods of a storm and
is usually expressed as cm/ hour.
Duration of Storm
In the case of a complex storm, we can divide it into a series of storms of different durations,
during which the intensity is more or less uniform.
Aerial distribution
During a storm, the rainfall intensity or depth etc. will not be uniform over the entire area.
Hence we must consider the variation over the area i.e. the aerial distribution of rainfall
over which rainfall is uniform.
Delineation of watershed and estimation of discharge of River Shimsha using GIS 2015 - 16
Dept. of Civil Engineering, CIT, Gubbi. 6
2.2.3 Measurement of rainfall
Precipitation is measured as depth of water equivalent from all forms that would
accumulate on a horizontal surface if there are no losses. The vertical depth of water is
expressed in millimetres. Precipitation data is a basic input for the study of any water
resources system and should be measured extensively. Due to its great variability in space
and time this natural parameter is recorded continuously. Rainfall is collected and measured
in instruments called rain gauges. Three types of instruments generally used for
measurement of rainfall are:
Non-recording gauge
Recording gauge
Weather radars
2.2.4 Average annual rainfall
The amount of rain collected by a given rain gauge in 24 hours is known as daily rainfall,
and the amount collected in one year is known as annual rainfall. This annual rainfall at a
given station should be recorded over a number of years, say 35 to 40 years or so. In India,
this rainfall cycle period is taken to be about 35 years. The mean annual rainfalls over a
period of 35 year or so, is therefore, known as average annual rainfall or normal annual
rainfall of the given station. Whenever, we talk of the rainfall at any given place, we
generally refer to the average annual rainfall of that place.
2.2.5 Losses of precipitation
Losses from precipitation is defined as the quantity that does not yield for hydropower
generation, irrigation, domestic water supply, navigation and other uses. Thus, for a surface
water resource engineer, the difference between precipitation and runoff in a stream is, a
loss, which can be taken as the sum of the losses of:
i. Evaporation
ii. Transpiration
iii. Interception
iv. Depression storage
v. Infiltration
These losses form a major portion of the hydrologic cycle.
Delineation of watershed and estimation of discharge of River Shimsha using GIS 2015 - 16
Dept. of Civil Engineering, CIT, Gubbi. 7
2.3 Runoff
Runoff means the drainage or flowing off of precipitation from a catchment area through a
surface channel. It thus represents the output from the catchment in a given unit of time.
Overland flow
After considering all the losses, the excess precipitation moves over the land surfaces to
reach smaller channels. This portion of the runoff is called overland flow and building up
of a storage over the surface and draining off of the same.
Surface runoff
The flow in this mode, where it travels all the time over the surface as overland flow and
through the channels as open-channel flow and reaches the catchment outlet is called
surface runoff.
Interflow
A part of the precipitation that infilters moves laterally through upper crusts of the soil and
returns to the surface at some location away from the point of entry into the soil. This
component of runoff is known variously as interflow, through flow, storm seepage.
Groundwater flow
Another route for the infiltered water is to undergo deep percolation and reach the
groundwater storage in the soil. The groundwater flows follows a complicated and long
path of travel and ultimately reached the surface. This part of runoff is called groundwater
runoff or groundwater flow. Groundwater flow provides the dry-weather flow in perennial
streams.
2.4 Stream
A stream can be defined as a flow channel into which surface runoff from a specified basin
drains and represents the total response of a basin undergoing frequent interactions between
its various processes and storages. There is a considerable exchange of water between a
stream and the ground water. The stream flow is measured in units of discharge
(m3/second).
2.5 Strahler stream order
In mathematics, the Strahler number or Horton–Strahler number of a mathematical tree is
a numerical measure of its branching complexity. These numbers were first developed in
hydrology by Robert E. Horton (1945) and Arthur Newell Strahler (1952, 1957); in this
Delineation of watershed and estimation of discharge of River Shimsha using GIS 2015 - 16
Dept. of Civil Engineering, CIT, Gubbi. 8
application, they are referred to as the Strahler stream order and are used to define stream
size based on a hierarchy of tributaries. (Wikipedia, Strahler number n.d.) (Amanda n.d.)
When using stream order to classify a stream, the sizes range from a first order stream all
the way to the largest, a 12th order stream. A first order stream is the smallest of the world's
streams and consists of small tributaries. These are the streams that flow into and "feed"
larger streams but do not normally have any water flowing into them. In addition, first and
second order streams generally form on steep slopes and flow quickly until they slow down
and meet the next order waterway.
First through third order streams are also called headwater streams and constitute any
waterways in the upper reaches of the watershed. It is estimated that over 80% of the
world’s waterways are these first through third order, or headwater streams. Going up in
size and strength, streams that are classified as fourth through sixth order are medium
streams while anything larger (up to 12th order) is considered a river. The world’s largest
river, the Amazon in South America, is considered a 12th order stream.
Unlike the smaller order streams, these medium and large rivers are usually less steep and
flow slower. They do however tend to have larger volumes of runoff and debris as it collects
in them from the smaller waterways flowing into them. (Figure 2.2)
Figure 2.2 Diagram showing the Strahler stream order
Delineation of watershed and estimation of discharge of River Shimsha using GIS 2015 - 16
Dept. of Civil Engineering, CIT, Gubbi. 9
2.5.1 Ordering
When studying stream order, it is important to recognize the pattern associated with the
movement of streams up the hierarchy of strength. Because the smallest tributaries are
classified as first order, they are often given a value of one by scientists (shown here). It
then takes a joining of two first order streams to form a second order stream. When two
second order streams combine, they form a third order stream, and when two third order
streams join, they form a fourth and so on.
If however, two streams of different order join, neither increases in order. For example, if
a second order stream joins a third order stream, the second order stream simply ends by
flowing its contents into the third order stream, which then maintains its place in the
hierarchy.
2.5.2 Importance of stream order
This method of classifying stream size is important to geographers, geologists, hydrologists
and other scientists because it gives them an idea of the size and strength of specific
waterways within stream networks- an important component to water management. In
addition, classifying stream order allows scientists to more easily study the amount of
sediment in an area and more effectively use waterways as natural resources.
Stream order also helps people like bio-geographers and biologists in determining what
types of life might be present in the waterway. More recently, stream order has also been
used in geographic information systems (GIS) in an effort to map river networks.
Whether it is used by a GIS, a bio-geographer, or a hydrologist, stream order is an effective
way to classify the world’s waterways and is a crucial step in understanding and managing
the many differences between streams of different sizes.
2.6 Watershed
A watershed, also called a drainage basin or catchment area, is defined as an area in which
all water flowing into it goes to a common outlet. It is bounded by the highest contour
called ridge line from where precipitated water is collected by the surface and subsurface
flows and drained out through the natural river. The ridge line forms a natural barrier
dividing one basin from another. People and livestock are the integral part of watershed
and their activities affect the productive status of watersheds and vice versa. From the
hydrological point of view, the different phases of hydrological cycle in a watershed are
dependent on the various natural features and human activities. Watershed is not simply
the hydrological unit but also socio-political-ecological entity which plays crucial role
Delineation of watershed and estimation of discharge of River Shimsha using GIS 2015 - 16
Dept. of Civil Engineering, CIT, Gubbi. 10
in determining food, social, and economical security and provides life support services
to rural people.
2.7 Delineation of watershed
Hydrologically, watershed is an area from which the runoff flows to a common point on
the drainage system. Every stream, tributary, or river has an associated watershed, and
small watersheds aggregate together to become larger watersheds. Water travels from
headwater to the downward location and meets with similar strength of stream, then it forms
one order higher stream. The stream order is a measure of the degree of stream branching
within a watershed. Each length of stream is indicated by its order based on Strahler stream
ordering (for example, first-order, second-order, etc.). The start or headwaters of a stream,
with no other streams flowing into it, is called the first-order stream. Stream order describes
the relative location of the reach in the watershed. Identifying stream order is useful to
understand amount of water availability in reach and its quality; and also used as criteria to
divide larger watershed into smaller unit. Moreover, criteria for selecting watershed size
also depend on the objectives of the development and terrain slope. A large watershed can
be managed in plain valley areas or where forest or pasture development is the main
objective. In hilly areas or where intensive agriculture development is planned, the size of
watershed relatively preferred is small.
Figure 2.3 Watershed delineation based on Strahler stream order
Delineation of watershed and estimation of discharge of River Shimsha using GIS 2015 - 16
Dept. of Civil Engineering, CIT, Gubbi. 11
2.8 Rainfall-Runoff estimation
Many empirical formulae are developed based on the study of different catchments. They
became popular because their utilization is simple, easy and reliable. Still there are many
watersheds or catchments which are ungauged so there we can use these empirical formulas
for estimating runoff volume and watershed planning and managements. Following
empirical formulas used for calculation purpose. (Patra 2008)
Inglis formulae
Khosala method
Lecys method
Strange’s table
Barlow’s tables
SCS curve number method
2.9 Strange’s table
Strange (1892) studied the available rainfall and runoff in the border areas of present-day
Maharashtra and Karnataka and has obtained yield ratios as functions of indicators
representing catchment characteristics. Catchments lie classified as good, average and bad
according to the relative magnitudes of yield they give. (Figure 2.4)
Since there is no appreciable runoff due to the rains in the dry (non-monsoon) period, the
monsoon season runoff volume is recommended to be taken as annual yield of the
catchment. This table could be used to estimate the monthly yields also in the monsoon
season. However, it is to be used with the understanding that the table indicates relationship
between cumulative monthly rainfall starting at the beginning of the season and cumulative
runoff, i.e. a double mass curve relationship. (Patra 2008) (Subramanya 2008) (Office of
the Chief Engineer 1990)
Delineation of watershed and estimation of discharge of River Shimsha using GIS 2015 - 16
Dept. of Civil Engineering, CIT, Gubbi. 12
Figure 2.4 Strange's table
Delineation of watershed and estimation of discharge of River Shimsha using GIS 2015 - 16
Dept. of Civil Engineering, CIT, Gubbi. 13
2.10 Water resource management
Water resource management is the activity of planning, developing, distributing and
managing the optimum use of water resources. Ideally, water resource management
planning has regard to all the competing demands for water and seeks to allocate water on
an equitable basis to satisfy all uses and demands.
2.10.1 Need for watershed management
Out of all the water available on the Earth, 97 % of water is saline and is in oceans and only
3% of water is freshwater; slightly over two thirds of this is frozen in glaciers and polar ice
caps. The remaining unfrozen freshwater is found mainly as groundwater, with only a small
fraction present above ground or in the air.
The thirst of water for India’s rapid development is growing day by day. In spite of adequate
average rainfall in India, there is large area under the less water conditions/drought prone.
There are lot of places, where the quality of groundwater is not good. Another issue lies in
interstate distribution of rivers. Water supply of the 90% of India’s territory is served by
interstate rivers. It has created growing number of conflicts across the states and to the
whole country on water sharing issues.
One of the biggest concerns for our water-based resources in the future is the sustainability
of the current and even future water resource allocation. As water becomes more scarce,
the importance of how it is managed grows vastly. Finding a balance between what is
needed by humans and what is needed in the environment is an important step in the
sustainability of water resources.
Delineation of watershed and estimation of discharge of River Shimsha using GIS 2015 - 16
Dept. of Civil Engineering, CIT, Gubbi. 14
Chapter 3
GEOGRAPHIC INFORMATION SYSTEM (GIS)
3.1 General
A GIS is a computer based system that provides the following four sets of capabilities to
handle geo-referenced data.
1. Data capture and preparation
2. Data management, including storage and maintenance
3. Data manipulation and analysis
4. Data presentation
GIS is a tool for working with geographic information.
Data used in GIS are generally positional data, also called as spatial data. Spatial data refers
to where they were or will be in the geographic space which is defined relative to Earth’s
surface.
Data in many different forms can be entered into GIS. Data that are already in map form
can be included in GIS. This includes such information as the location of rivers and roads,
hills and valleys. GIS can also include data in table form, such as population information.
Data from Remote Sensing satellites in a variety of spatial, spectral and temporal
resolutions are used for various applications of resources survey and management can be
imported into GIS flawlessly.
GIS applications are tools that allow users to create interactive queries (user-created
searches), analyse spatial information, edit data in maps, and present the results of all these
operations. Geographic information science is the science underlying geographic concepts,
applications, and systems.
GIS can relate unrelated information by using location as the key index variable. Locations
or extents in the Earth space–time may be recorded as dates/times of occurrence, and x, y,
and z coordinates representing, longitude, latitude, and elevation, respectively. All Earth-
based spatial–temporal location and extent references should, ideally, be relatable to one
another and ultimately to a "real" physical location or extent.
Modern GIS technologies use digital information, for which various digitized data creation
methods are used. The most common method of data creation is digitization, where a hard
Delineation of watershed and estimation of discharge of River Shimsha using GIS 2015 - 16
Dept. of Civil Engineering, CIT, Gubbi. 15
copy map or survey plan is transferred into a digital medium through the use of a CAD
program, and geo-referencing capabilities. (Otto and Rolf A.De 2001)
3.2 Data representation in GIS
Conventionally, there are two broad methods of storing the data in GIS. (Figure 3.1)
i. Vector
Examples for Vector data:
• Points of towns, trees, electric pole, etc.
• Lines for highways, streams, sewer lines, etc.
• Polygons for houses, tanks, playground, etc.
ii. Raster
Examples for Raster data:
• Satellite imagery
• DEM
• Scanned maps / toposheets
• Online Map Layers
Figure 3.1 Data representation in GIS
Delineation of watershed and estimation of discharge of River Shimsha using GIS 2015 - 16
Dept. of Civil Engineering, CIT, Gubbi. 16
3.3 Geo referencing
Handling spatial information requires the establishment of a spatial reference system to
which all spatial measurements must relate. The primary function off the map is to portray
accurately real world features that occur on the curved surface of the earth.
Geographic referencing which is sometimes simply called as geo referencing, is defined as
the representation of the location of real world features within the spatial framework of a
particular system.
The objective of geo referencing can be seen as the series of concepts and techniques that
progressively transform measurements carried out on the irregular surface of the earth to a
flat surface of a map, and male it easily and readily measureable on this flat surface by
means of coordinate system.
Map data are different from all other forms of data by this characteristic of geo referencing
and the ability to manipulate and analyse geo referenced spatial data is what distinguishes
GIS from other types of computer graphic systems.
3.4 Digitization
Digitizing is the process by which coordinates from a map, image, or other sources of data
are converted into a digital format in a GIS. This process becomes necessary when available
data is gathered in formats that cannot be immediately integrated with other GIS data. In
regard to spatial information one application of this is the process of creating a vector digital
database by creating point, line and polygon objects.
3.5 Remote Sensing
Remote sensing is the science of obtaining information about objects or areas from a
distance, It may be split into active remote sensing (when a signal is first emitted from
aircraft or satellites or passive (e.g. sunlight) when information is merely recorded typically
from aircraft or satellites.
Remote sensing makes it possible to collect data of dangerous or inaccessible areas. Remote
sensing applications include monitoring deforestation in areas such as the Amazon Basin,
glacial features in Arctic and Antarctic regions, and depth sounding of coastal and ocean
depths. Military collection during the Cold War made use of stand-off collection of data
about dangerous border areas. Remote sensing also replaces costly and slow data collection
on the ground, ensuring in the process that areas or objects are not disturbed.
Delineation of watershed and estimation of discharge of River Shimsha using GIS 2015 - 16
Dept. of Civil Engineering, CIT, Gubbi. 17
Reflected sunlight is the most common source of radiation measured by passive sensors.
Examples of passive remote sensors include film photography, infrared, charge-coupled
devices, and radiometers. Active collection, on the other hand, emits energy in order to
scan objects and areas whereupon a sensor then detects and measures the radiation that is
reflected or backscattered from the target. RADAR and LiDAR are examples of active
remote sensing where the time delay between emission and return is measured, establishing
the location, speed and direction of an object.
3.6 Applications of GIS
GIS is involved in various areas. These include topographical mapping, socioeconomic and
environment modelling, and education. Some examples include,
Urban planning
Crime mapping
GIS and Hydrology
Remote sensing applications
Transport and Road networking
Wastewater and storm water systems
Waste management
Health/Medical resource management
Meteorology and Disaster management
Delineation of watershed and estimation of discharge of River Shimsha using GIS 2015 - 16
Dept. of Civil Engineering, CIT, Gubbi. 18
3.6.1 GIS in hydrology and water resource management
Geographic information systems (GIS) have become a useful and important tool in
hydrology and to hydrologists in the scientific study and management of water resources.
Climate change and greater demands on water resources require a more knowledgeable
disposition of arguably one of our most vital resources. As every hydrologist knows, water
is constantly in motion. Because water in its occurrence varies spatially and temporally
throughout the hydrologic cycle, its study using GIS is especially practical. GIS systems
previously were mostly static in their geospatial representation of hydrologic features.
Today, GIS platforms have become increasingly dynamic, narrowing the gap between
historical data and current hydrologic reality.
The elementary water cycle has inputs equal to outputs plus or minus change in storage.
Hydrologists make use of a hydrologic budget when they study a watershed. A watershed
is a spatial area, and the occurrence of water throughout its space varies by time. In the
hydrologic budget are inputs such as precipitation, surface flows in, and groundwater flows
in. Outputs are evapotranspiration, infiltration, surface runoff, and surface/groundwater
flows out. All of these quantities, including storage, can be measured or estimated, and their
characteristics can be graphically displayed in GIS and studied. By synthesizing GIS
technology with hydrologic data, it has become possible to elucidate the effects of
watershed-scale land-use and land-cover changes.
Delineation of watershed and estimation of discharge of River Shimsha using GIS 2015 - 16
Dept. of Civil Engineering, CIT, Gubbi. 19
Chapter 4
STUDY AREA
4.1 About
In the present study, watershed of River Shimsha being the region of interest, which
originates and flows through Tumakuru District is considered as study area. The river
originates in Devarayanadurga hills and flows through some of the major localities of
Tumakuru District namely Tumakuru city, Maidala, Gulur, Bheemasandra, Mallasandra,
Gubbi, Kadaba and Kallur. The river after feeding Kallur tank confluences with a stream
flowing from Turvekere tank. After which the river takes southern course and flows
towards Markonahalli reservoir and finally enters Mandya District. Considering the
confluence point at Kallur as a reference, the watershed is delineated for the upstream of
River Shimsha. The demarcated upstream watershed has an area of about 1288 sq. km
which is only a fraction of the entire catchment area of 8,469 sq. km. (Figures 4.1 and 4.2)
Figure 4.1 Location of study area
Delineation of watershed and estimation of discharge of River Shimsha using GIS 2015 - 16
Dept. of Civil Engineering, CIT, Gubbi. 20
Figure 4.2 Study area
4.2 Tumakuru District
4.2.1 General
Tumakuru district is located in the eastern belt in the southern half of the State. Spanning
an area of 10598 sq.km. this district lies between the latitudinal parallels of 12 degree 45
minutes North and 14 degree 22 minutes North and the longitudinal parallels of 76 degree
24 minutes East and 77 degree 30 minutes East. Tumakuru district is surrounded on all
sides by lands belonging to the neighbouring districts and has no natural boundary such as
sea, river or mountain ranges on any side. The landscape consists mainly of, undulating
plains interspersed with a sprinkling of hills. To the east of Tumakuru and north of
Devarayanadurga there is a short stretch of hilly country intersected by cultivated valleys.
4.2.2 Rivers
Shimsha, Jayamangali and Suvarnamukhi are the important rivers of the district. North
Pinakini flows through Pavagada taluk for a short distance. Likewise Kumudwati cuts
through the eastern borders of Madhugiri taluk.
Shimsha has its origins in the southern portion of the Devarayanadurga hill range and flows
in a general south by south-westerly direction cutting through the taluks of Tumakuru,
Turuvekere, Gubbi and Kunigal. After traversing a total distance of about 100 km this river
Delineation of watershed and estimation of discharge of River Shimsha using GIS 2015 - 16
Dept. of Civil Engineering, CIT, Gubbi. 21
enters Mandya district and finally joins the Cauvery. En route, this river feeds the large
Kadaba tank and is itself enriched by the numerous streams that flow into it from several
directions. Naga stream which joins it near Kallur and the Nagini stream that emerges from
the Kunigal tank and merges with the river near – Hanumapura are the streams that deserve
a special mention.
4.2.3 Forest and wildlife
About 4 per cent of the total area of the district stands classified as forests. The forest
regions are found to a large extent on the lower slopes of hill ranges. The forests are mostly
open and consist of mixed species varying from dry deciduous to thorny bushes. Because
of the scanty rainfall the trees are short, twisted, knotty and full of branches. The forests
contain very few timber species and the wood that is generally available is fit for use only
as fuel. These forests have also been over exploited since decades and the free grazing
facility permitted therein has had an inimical effect on the natural and artificial
regeneration. In the southern portion however there are forest tracts containing tall and well
grown trees. By and large it may be observed that the soil, rainfall and climatic conditions
are not quite favourable for the growth of rich and variegated vegetation. In the absence of
adequate forest cover the district has very few species of wild animals. Tiger, panther and
cheetah have now totally out migrated from these forests. Bear, wild boar, hyena, fox,
spotted deer and rabbit are the important species of wild animals encountered in the district.
4.2.4 Geology
Geologically, Tumakuru district is situated right on the Archaen complex. The rock
formations are represented by the crystalline schists, the granitic gneisses and the newer
granites. The crystalline schists of this district, which form the southern extension of the
well-defined. Chitradurga schist belt of the Dharwar system, are the oldest members of the
Archaean complex. The schist belt which passes to the east of Chiknayakanhalli send out,
near Banasandra, a branch that extends over 40 km. This narrow belt is composed of
chloritic schists, micaceous schists, quartzites, limestones and ferruginous quartzites.
Portions of the schist belt near Doddaguri exhibit the evidences of sedimentation. The thin
patches of schists scattered about in gneissic complex show evidences of repealed
metamorphism. These schists are intensely altered and new minerals like diopside,
hypcrthcnc, garnet, cordierite, sillimanite and corundum have developed giving rise to
several interesting rock types. A major portion of the district is covered by gneissic complex
which is said to be composed of four major components; banded gneisses, granitic gneisses,
gneissic granites and granites, and grano-diorites, diorites, inter-action diorites and other
Delineation of watershed and estimation of discharge of River Shimsha using GIS 2015 - 16
Dept. of Civil Engineering, CIT, Gubbi. 22
varieties. Gold, manganese, sillimanite, asbestos, corundum, feldspar, garnet, quartz,
ochres, clay, silver sand, soapstone and building as well as ornamental stones constitute the
chief items of mineral wealth. The soils of the district arc hard and poor in general. Red,
gravelly, sandy, clay, loam, black soil, sandy' loam and sandy clay arc the main types of
soil met with in various parts of the district.
4.2.5 Climate and rainfall
The climate of the district is quite agreeable and free from extremes. However, amongst
the taluks, Pavagada which is located in the north-cast is noted for its relatively hot climate.
The year is usually divided into four seasons: summer from March to May; rainy season or
south-west monsoon season from June to September; post-monsoon, season covering the
months of October and November and dry or winter season from December to February.
Generally the period from March to May is one of continuous and steady rise in
temperatures.
The average annual rainfall in the district is 687.9 mm. This amount of rainfall is subject
to considerable fluctuations from year to year. Within the district itself the northern and the
eastern regions receive comparatively lesser amounts of rainfall than their southern and
south-western counterparts. The average number of rainy days being 45, the number of
rainy days varies between 35 in Pavagada located in the north-east and 54 in Tumakuru
which enjoys a central location. The precipitation during the south-west monsoon period
usually accounts for 50 per cent of the annual rainfall and remaining 50 per cent of rainfall
is spread over the pre-monsoon months of April and May on the one hand and the northeast
monsoon months of October and November on the other. The remaining months of the year
are comparatively free from rains. September and October are the months which are noted
for heavy rainfall. It is during this period that the innumerable tanks of the district receive
large quantities of water and wells filled to the brim. Delays in the onset of these rains, as
also inadequate downpour during this period, quite often cause great anxiety and hardship
to the farmers of the district. Certain parts of the district are known to be often afflicted by
drought and scarcity conditions. (Deputy Commissioners Office n.d.)
Delineation of watershed and estimation of discharge of River Shimsha using GIS 2015 - 16
Dept. of Civil Engineering, CIT, Gubbi. 23
4.3 River Shimsha
Shimsha originates at an altitude of 914 m in the Devarayanadurga hill which is also the
location of two temples of the Hindu God, Narasimha.
After originating in the Tumakuru district, the river takes a southerly course and enters the
Mandya district. In Mandya district, the river flows in a south-eastern direction and has a
waterfall at Shimshapura in Malavalli Taluk. Just after Shimshapura it reaches the border
of Chamarajanagar district where it joins the river Kaveri. The confluence of Shimsha and
Kaveri is also near the Shivanasamudra falls. The total length of the river is 221 km. and
the river has a catchment area of 8469 km². Maddur is a major town that lies on this river.
In its course the river is joined by other smaller rivers and streams such as Veeravaishnavi,
Kanihalla, Chikkahole, Hebbahalla, Mullahalla and Kanva. (Wikipedia, Shimsha n.d.)
(Karnataka Water Resources n.d.)
4.3.1 Dam
Markonahalli Dam is a dam built across the river Shimsha in the Kunigal Taluk of
Tumakuru district. It was built by Krishnaraja Wodeyar IV, the king of Mysore under the
guidance of his Diwan, Sir M Visweswaraiah. It was built to irrigate 6070 hectares of land
and has a masonry structure of 139 m and a pair of earth dams extending to 1470 metres
on either side. The reservoir has a catchment area of 4,103 km2 and can hold a volume of
68 million m³ of water at a full reservoir level of 731.57 m above the mean sea level. (Figure
4.3)
4.3.2 Power generation
Shimsha has a waterfall at Shimshapura in Malavalli Taluk. This is also the location of the
Shimsha Hydro Electric Project which has an installed capacity of 17,200 kilowatts.
Figure 4.3 Markonahalli Dam and Shimshapura Power Generation house
Delineation of watershed and estimation of discharge of River Shimsha using GIS 2015 - 16
Dept. of Civil Engineering, CIT, Gubbi. 24
Chapter 5
DATA, TOOLS AND METHOD
5.1 Data
5.1.1 Toposheets
A toposheet is a shortened name for 'Topographic sheet'. They essentially contain
information about an area like roads, railways, settlements, canals, rivers, contours, etc.
According to their usage, they may be available at different scales (e.g. 1:25000, 1: 50000
etc., where the former is a larger scale as compared to the latter). They are made on a
suitable projection for that area and contain latitude - longitude information at the corners.
Thus any point on it can be identified with its corresponding latitude - longitude, depending
upon the scale (i.e. if the scale is large, more accurate are the coordinates). (Figure 5.1)
The Survey of India is responsible for all topographic control, surveys and mapping in
India.
Figure 5.1 Toposheet of Gubbi region (57C/15) procured from Survey of India
Delineation of watershed and estimation of discharge of River Shimsha using GIS 2015 - 16
Dept. of Civil Engineering, CIT, Gubbi. 25
Applications: Topographic maps have multiple uses in the present day: any type of
geographic planning or large-scale architecture; earth sciences and many other geographic
disciplines; mining and other earth-based endeavours; civil engineering and recreational
uses such as hiking and orienteering.
The toposheets at a scale of 1: 50,000 encompassing the study area were procured from the
Map Sale Office, Survey of India, Bengaluru.
Toposheets used: 57C/11 (D43Q11), 57C/12 (D43Q12), 57C/15 (D43Q15), 57C/16
(D43Q16), 57G/2 (D43R2), 57G/3 (D43R3), 57G/4 (D43R4), 57G/7 (D43R7), 57G/8
(D43R8). (Figure 5.2)
Figure 5.2 Toposheet indexing
Delineation of watershed and estimation of discharge of River Shimsha using GIS 2015 - 16
Dept. of Civil Engineering, CIT, Gubbi. 26
5.1.2 Digital Elevation Model (DEM)
A digital elevation model (DEM) is a digital model or 3D representation of a terrain's
surface of the earth created from terrain elevation data. In this project, ASTER GDEM is
used for watershed modelling with GRASS GIS. ASTER GDEM is a satellite based DEM
available at a resolution of 30m.
‘GDEM’ stands for Global Digital Elevation Model and ‘ASTER’ – Advanced Space borne
Thermal Emission and Reflection Radiometer. ASTER GDEM is a combined effort from
the Ministry of Economy, Trade, and Industry (METI) of Japan and the United States’
National Aeronautics and Space Administration (NASA).
Various DEM products available are,
i. ISRO’s Cartosat at 30 m resolution
ii. SRTM at 90m resolution by NASA
iii. ASTER GDEM at 30m resolution
The ASTER digital elevation model for the study area was obtained from USGS Global
Data Explorer, NASA Earth Data (http://gdex.cr.usgs.gov/gdex/) by registering as a user
of NASA earth data. (Figure 5.3)
Figure 5.3 ASTER DEM
Delineation of watershed and estimation of discharge of River Shimsha using GIS 2015 - 16
Dept. of Civil Engineering, CIT, Gubbi. 27
5.1.3 Rainfall data
Daily rainfall data from 1901 to 2014 of all the rain gauge stations of Tumakuru District
were collected from the Directorate of Economics and Statistics, Government of Karnataka,
M. S. Buildings, Bengaluru. There are 71 rain gauge stations in Tumakuru District and
about 20 of them can be located inside the watershed of River Shimsha. (Figure 5.4)
Figure 5.4 Geo-located rain gauge stations of Tumakuru District
5.1.4 Other data
District at a glance: Tumakuru District at a glance for 2013 – 2014 published by the
District Statistical Office, Tumakuru was collected which contains several information
such as general information of district, area and population data as per 2011 Census,
information regarding agriculture, land utilization, etc.
Tank details: Various information on existing tanks of Tumakuru District were collected
from Minor Irrigation Department, Hemavathi Neeravari Nigama, and Panchayat Raj
Engineering Department (Zilla Panchayat), Tumakuru.
Delineation of watershed and estimation of discharge of River Shimsha using GIS 2015 - 16
Dept. of Civil Engineering, CIT, Gubbi. 28
5.2 Tools
5.2.1 QGIS
QGIS (previously known as Quantum GIS) is a cross-platform free and open-source
desktop geographic information system (GIS) application that provides data viewing,
editing, and analysis. The application is available from http://qgis.org/. QGIS allows users
to create maps with many layers using different map projections. Maps can be assembled
in different formats and for different uses. QGIS allows maps to be composed of raster or
vector layers. Typical for this kind of software, the vector data is stored as either point, line,
or polygon-feature. Different kinds of raster images are supported, and the software can
geo-reference images. (Figure 5.5)
QGIS supports dxf, shapefiles, coverages, and personal geo-databases. MapInfo, PostGIS,
and a number of other formats. Web services, including Web Map Service and Web Feature
Service, are also supported to allow use of data from external sources.
QGIS integrates with other open-source GIS packages, including PostGIS, GRASS, and
MapServer to give users extensive functionality. Plugins written in Python or C++ extend
QGIS's capabilities. Plugins can geocode using the Google Geocoding API, perform
geoprocessing using fTools, which are similar to the standard tools found in ArcGIS, and
interface with PostgreSQL/PostGIS, SpatiaLite and MySQL databases.
For this study, QGIS version 2.12 ‘Lyon’ was used as GIS application. (Figure 5.6)
Figure 5.5 QGIS logo
Delineation of watershed and estimation of discharge of River Shimsha using GIS 2015 - 16
Dept. of Civil Engineering, CIT, Gubbi. 29
Figure 5.6 QGIS Screen
5.2.2 GRASS GIS
Geographic Resources Analysis Support System (commonly termed GRASS GIS) is a
geographic information system (GIS) software suite used for geospatial data management
and analysis, image processing, producing graphics and maps, spatial and temporal
modelling, and visualizing. It can handle raster, topological vector, image processing, and
graphic data. The application is available from https://grass.osgeo.org/.
GRASS supports raster and vector data in two and three dimensions. The vector data model
is topological, meaning that areas are defined by boundaries and centroids; boundaries
cannot overlap within one layer. In contrast, OpenGIS Simple Features, defines vectors
more freely, much as a non-georeferenced vector illustration program does.
GRASS GIS contains over 350 modules to render maps and images on monitor and paper;
manipulate raster and vector data including vector networks; process multispectral image
data; and create, manage, and store spatial data. Users can interface with the software
features through a graphical user interface (GUI) or by plugging into GRASS via other
software such as QGIS. They can also interface with the modules directly through a
bespoke shell that the application launches or by calling individual modules directly from
a standard shell.
In this study, GRASS GIS 6.4 plugin with QGIS was used for hydrologic modelling of the
watershed based on the elevation data from ASTER digital elevation model. (Figure 5.7)
Delineation of watershed and estimation of discharge of River Shimsha using GIS 2015 - 16
Dept. of Civil Engineering, CIT, Gubbi. 30
Figure 5.7 QGIS with GRASS plugin
5.2.3 Other tools
Google Earth: Google Earth is a virtual globe, map and geographical information program
that was originally called EarthViewer 3D created by Keyhole, Inc., a Central Intelligence
Agency (CIA) funded company acquired by Google in 2004. It maps the Earth by the
superimposition of images obtained from satellite imagery, aerial photography and
geographic information system (GIS) onto a 3D globe.
Google Earth was used to geo-locate the rain gauge stations of Tumakuru District and the
geo located points were then exported to QGIS for further analysis.
OpenStreetMap: OpenStreetMap (OSM) is a collaborative project to create a free editable
map of the world. Two major driving forces behind the establishment and growth of OSM
have been restrictions on use or availability of map information across much of the world
and the advent of inexpensive portable satellite navigation devices. OSM is considered a
prominent example of volunteered geographic information.
To access the existing geospatial data, OpenStreetMap (http://www.openstreetmap.org)
was used in the study.
MS Excel: Microsoft Excel is a spreadsheet software developed by Microsoft. It features
calculation, graphing tools, pivot tables, and a macro programming language called Visual
Basic for Applications. MS Excel was used for analysis of rainfall data and to determine
mean annual rainfalls of each station with the help of pivot table.
Delineation of watershed and estimation of discharge of River Shimsha using GIS 2015 - 16
Dept. of Civil Engineering, CIT, Gubbi. 31
5.3 Methods
The methods that was followed to delineate watershed of River Shimsha is depicted in
Figure 5.8. To start with, toposheets from Survey of India for the study area (at a scale of
1:50000) were collected. With the help of GIS tool (QGIS), these were geo-referenced as
raster layers and the digitization of dendritic drainage pattern was carried out. For stream
ordering, Strahler Horton’s law was followed by designating an un-branched stream as first
order stream, when two first order streams joined it was designated as second order. Two
second order steams join together to form third order and so on. The number of streams of
each order were counted and recorded. The drainage map along with basin boundaries were
digitized as a line coverage giving unique id for each order of stream.
Subsequently, the elevation data in the form of digital elevation model from ASTER was
downloaded and processed in the GIS tool (QGIS with GRASS plugin). Mainly three layers
constituting stream segments, micro watershed basins and accumulation of the basin were
derived based on the elevation of the terrain. This was analysed to derive the catchment
characteristics. A thematic map was generated indicating the drainage basin of the
watershed.
Morphometric parameters under linear and shape were computed using standard methods
and formulae (Horton 1932, 1945; Smith 1954; Strahler, 1964).The fundamental parameter
namely; stream length, area, perimeter, number of streams and basin length were derived
from drainage layer. Verification of these were carried for a select sample of streams
derived from the above methods through field visits which aided in assessing the current
status of some of the streams in reality and data derived from the above method.
In the next phase, rainfall data were collected and analysed using a spreadsheet package
(MS Excel). The total rainfall and average annual rainfall of watershed were calculated.
Strange’s table – a method for rainfall-runoff computation was used to estimate the
potential yield of runoff from the watershed delineated for the upstream of River Shimsha
as described earlier (Chapter 4, Study Area).
Delineation of watershed and estimation of discharge of River Shimsha using GIS 2015 - 16
Dept. of Civil Engineering, CIT, Gubbi. 32
Figure 5.8 Method
Delineation of watershed and estimation of discharge of River Shimsha using GIS 2015 - 16
Dept. of Civil Engineering, CIT, Gubbi. 33
Chapter 6
RESULTS AND DISCUSSION
6.1 Results
6.1.1 Watershed delineation
The watershed of River Shimsha has been delineated and has an area of 1288 sq. km and a
perimeter of 215 km. With toposheets as a reference, the watershed of River Shimsha was
delineated by digitizing the streams and tanks from the map in GIS to produce a thematic
map indicating various orders of stream network along with tanks overlaid. Similarly a
thematic map was generated out of the DEM method by processing the stream segments
derived based on the elevation of the ground. (Figures 6.1 and 6.2)
Morphometric parameters were derived for both the methods based on length and number
of stream segments derived from the respective methods. The morphometric parameters
derived from both methods have been showcased in the following tables.
General characteristics of the catchment:
Table 6.1 General characteristics of the watershed
Area of watershed 1288.13 sq.km
Perimeter of Watershed 214.52 km
Basin Length 55.74 km
Minimum altitude 713 m
Maximum altitude 1272 m
Highest order stream 6th
Table 6.2 Details of tanks in the watershed
Number
of tanks
Total water
spread area of
tanks (in sq.km)
Total water
spread area of
tanks (in ha)
Tanks in the study area 302 83173.47 83.17
Tanks with area 0 - 100 ha 154 6407.44 6.41
Tanks with area 101 to 1000 ha 133 1964.36 1.96
Tanks with area 1001 to 2000 ha 10 8436.46 8.44
Tanks with area more than 2000 ha 5 18656.69 18.66
Delineation of watershed and estimation of discharge of River Shimsha using GIS 2015 - 16
Dept. of Civil Engineering, CIT, Gubbi. 34
Figure 6.1 Thematic map generated from toposheet method
Delineation of watershed and estimation of discharge of River Shimsha using GIS 2015 - 16
Dept. of Civil Engineering, CIT, Gubbi. 35
Figure 6.2 Thematic map generated from DEM method
Delineation of watershed and estimation of discharge of River Shimsha using GIS 2015 - 16
Dept. of Civil Engineering, CIT, Gubbi. 36
6.1.2 Morphometric parameters
The following paragraphs describe the physical meaning of various morphometric
parameters. Further values of these parameters are obtained as per methods proposed by
various researchers for the study area and indicated in respective descriptions. (Hajam,
Aadil, & SamiUllah, 2013; Waikar & Nilawar, 2014)
Linear aspects
The linear aspects of morphometric analysis of basin include stream order, stream length,
mean stream length, stream length ratio and bifurcation ratio.
Stream order (U)
There are four different system of ordering streams that are available (Gravelius, 1914;
Horton, 1945; Strahler, 1952; Schideggar, 1970). Strahler’s system, which is a slightly
modified of Hortons system, has been followed because of its simplicity, where the
smallest, unbranched fingertip streams are designated as 1st order, the confluence of two
1st order channels give a channels segments of 2nd order, two 2nd order streams join to form
a segment of 3rd order and so on. When two channel of different order join then the higher
order is maintained. The trunk stream is the stream segment of highest order. Drainage
patterns of stream network from the basin have been observed as mainly of dendritic type
which indicates the homogeneity in texture and lack of structural control. The properties of
the stream networks are very important to study basin characteristics (Strahler, 2002). As
per the Strahler’s ordering scheme, the study area has a 6th order drainage basin. Higher
stream order is associated with greater discharge.
Stream length (Lu)
The stream length (Lu) has been computed based on the law proposed by Horton. Stream
length is one of the most significant hydrological features of the basin as it reveals surface
runoff characteristics. The stream of relatively smaller length is characteristics of areas with
larger slopes and finer textures. Longer lengths of streams are generally indicative of flatter
gradient. Generally, the total length of stream segments is maximum in first order stream
and decreases as stream order increases. The number of streams of various orders in a
watershed are counted and their lengths from mouth to drainage divided are measured with
the help of GIS software. The change may indicate flowing of streams from high altitude,
lithological variation and moderately steep slopes (Singh, 1997).The observation of stream
order verifies the Horton’s law of stream number i.e. the number of stream segment of each
order forms an inverse geometric sequence with order number.
Delineation of watershed and estimation of discharge of River Shimsha using GIS 2015 - 16
Dept. of Civil Engineering, CIT, Gubbi. 37
Mean stream length (Lsm)
The mean stream length is a characteristic property related to the drainage network and its
associated surfaces (Strahler, 1964), .The mean stream length (Lsm) has been calculated by
dividing the total stream length of order by the number of stream. The mean stream length
of stream increases with increase of the order.
Stream length ratio (RL)
The stream length ratio can be defined as the ratio of the mean stream length of a given
order to the mean stream length of next lower order and has an important relationship with
surface flow and discharge (Horton, 1945). The RL values between streams of different
order in the basin reveal that there are variations in slope and topography.
Bifurcation ratio (Rb)
Bifurcation ratio (Rb) may be defined as the ratio of the number of stream segments of given
order to the number of segments of the next higher order (Schumn 1956). Horton (1945)
considered the bifurcation ratio as an index of relief and dissections. Strahler (1957)
demonstrated that the bifurcation ratio shows a small range of variation for different regions
or different environmental conditions, except where the geology dominates. It is observed
that Rb is not the same from one order to its next order. Usually these values are common
in the areas where geologic structures do not exercise a dominant influence on the drainage
pattern.
Relief aspects
The relief aspects determined include relief ratio, relative relief and ruggedness number.
Relief ratio (Rh)
The relief ratio, (Rh) is ratio of maximum relief to horizontal distance along the longest
dimension of the basin parallel to the principal drainage line (Schumm, 1956). The Rh
normally increases with decreasing drainage area and size of watersheds of a given drainage
basin (Gottschalk, 1964). Relief ratio measures the overall steepness of a drainage basin
and is an indicator of the intensity of erosion process operating on slope of the basin
(Schumm, 1956). The relief ratio of the study area was 10.03.
Relative relief (Rbh)
This term was given by Melton (1957). In the present study area it is obtained by visual
analysis of the digital elevation model ASTER GDEM data. The elevation varies from 713
m to 1272 m which represent the land has gentle to moderate slope. The basin relief for the
basin was found to be 559 m.
Delineation of watershed and estimation of discharge of River Shimsha using GIS 2015 - 16
Dept. of Civil Engineering, CIT, Gubbi. 38
Ruggedness number (Rn)
It is the product of maximum basin relief (H) and drainage density (Dd), where both
parameters are in the same unit. An extreme high value of ruggedness number occurs when
both variables are large and slope is steep (Strahler, 1956). The value of ruggedness number
in present basin is 848.78 (Schumm, 1956).
Aerial aspects
It deals with the total area projected upon a horizontal plane contributing overland flow to
the channel segment of the given order and includes all tributaries of lower order. It
comprises of drainage density, drainage texture, stream frequency, form factor, circularity
ratio, elongation ratio and length of overland flow.
Drainage density (Dd)
Horton (1932), introduced the drainage density (Dd) is an important indicator of the linear
scale of land form elements in stream eroded topography. It is the ratio of total channel
segment length cumulated for all order within a basin to the basin area, which is expressed
in terms of km/km2. The drainage density, indicates the closeness of spacing of channels,
thus providing a quantitative measure of the average length of stream channel for the whole
basin. It has been observed from drainage density measurement made over a wide range of
geologic and climatic type that a low drainage density is more likely to occur in region and
highly resistant of highly permeable subsoil material under dense vegetative cover and
where relief is low. High drainage density is the resultant of weak or impermeable
subsurface material, sparse vegetation and mountainous relief. Low drainage density leads
to coarse drainage texture while high drainage density leads to fine drainage texture
(Strahaler, 1964).The drainage density (Dd) of study area is 1.52 km/km2 indicating
moderate drainage densities. The moderate drainage density indicates the basin is highly
permeable subsoil and vegetative cover (Nag, 1998).
Drainage pattern (Dp)
Drainage pattern presents some characteristics of drainage basins through drainage pattern
and drainage texture. It is possible to deduce the geology of the basin, the strike and dip of
depositional rocks, existence of faults and other information about geological structure
from drainage patterns from the figure. Drainage texture reflects climate, permeability of
rocks, vegetation, and relief ratio, etc. Howard (1967) related drainage patterns to
geological information. In the study area the drainage pattern is found to be dendritic.
Dendritic pattern is most common pattern is formed in a drainage basin composed of fairly
Delineation of watershed and estimation of discharge of River Shimsha using GIS 2015 - 16
Dept. of Civil Engineering, CIT, Gubbi. 39
homogeneous rock without control by the underlying geologic structure. The longer the
time of formation of a drainage basin is, the more easily the dendritic pattern is formed.
Figure 6.3 Classification of drainage pattern
Stream frequency (Fs)
Stream frequency (Fs), is expressed as the total number of stream segments of all orders per
unit area. It exhibits positive correlation with drainage density in the watershed indicating
an increase in stream population with respect to increase in drainage density. The Fs for the
basin is 1.34 (Horton, 1932)
Texture ratio (T)
Drainage texture ratio (T) is the total number of stream segments of all orders per perimeter
of that area (Horton, 1945). It depends upon a number of natural factors such as climate,
rainfall, vegetation, rock and soil type, infiltration capacity, relief and stage of development.
In the present study the texture ratio of the basin is 5.69.
Form factor (Ff)
Form factor (Ff) is defined as the ratio of the basin area to the square of the basin length.
This factor indicates the flow intensity of a basin of a defined area (Horton, 1945). The
form factor value should be always less than 0.7854 (the value corresponding to a perfectly
circular basin). The smaller the value of the form factor, the more elongated will be the
basin. Basins with high form factors experience larger peak flows of shorter duration,
whereas elongated watersheds with low form factors experience lower peak flows of longer
duration. The Ff value for study area is 0.41, indicating elongated basin with lower peak
flows of longer duration than the average.
Circulatory ratio (Rc)
Circularity Ratio is the ratio of the area of a basin to the area of circle having the same
circumference as the perimeter of the basin (Miller, 1953). It is influenced by the length
Delineation of watershed and estimation of discharge of River Shimsha using GIS 2015 - 16
Dept. of Civil Engineering, CIT, Gubbi. 40
and frequency of streams, geological structures, land use/ land cover, climate and slope of
the basin. The Rc value of basin is 0.32 and it indicates the basin is characterized by
moderate to low relief and drainage system seems to be less influenced by structural
disturbances. The high value of circularity ratio shows the late maturity stage of
topography.
Elongation ratio (Re)
Schumm (1956) defined elongation ratio as the ratio of diameter of a circle of the same area
as the drainage basin and the maximum length of the basin. Values of Re generally vary
from 0.6 to 1.0 over a wide variety of climatic and geologic types. Re values close to unity
correspond typically to regions of low relief, whereas values in the range 0.6–0.8 are
usually associated with high relief and steep ground slope (Strahler 1964). These values
can be grouped into three categories namely (a) circular (>0.9), (b) oval (0.9-0.8), (c) less
elongated (<0.7). The Re values in the study area is 0.36 indicating moderate to slightly
steep ground slope and area when collaborated with Strahler’s range seem to suggest an
elongated shape.
Length of overland flow (Lg)
The length of overland flow (Lg) is the length of water over the ground surface before it
gets concentrated into definite stream channel (Horton, 1945). Lg is one of the most
important independent variables affecting hydrologic and physiographic development of
drainage basins. The length of overland flow is approximately equal to the half of the
reciprocal of drainage density. This factor is related inversely to the average slope of the
channel and is quiet synonymous with the length of sheet flow to a large degree. The Lg
value of study area is 0.33 which shows gentler slopes in the valleys and hence low surface
runoff and longer flow paths.
Constant channel maintenance (C)
Schumm (1956) used the inverse of drainage density as a property termed constant of
stream maintenance C. This constant, in units of square feet per foot, has the dimension of
length and therefore increases in magnitude as the scale of the land-form unit increases.
Specifically, the constant C provides information of the number of square feet of watershed
surface required to sustain one linear foot of stream. The value C of basin is 0.66. It means
that on an average 0.66 sq. ft surface is needed in basin for creation of one linear foot of
the stream channel.
Delineation of watershed and estimation of discharge of River Shimsha using GIS 2015 - 16
Dept. of Civil Engineering, CIT, Gubbi. 41
Table 6.3 Method of calculating morphometric parameters of watershed
Method of Calculating Morphometric Parameters of Drainage
Basin
Morphometric
Parameters Formula/ Definition References
LIN
EA
R
Stream order (U) Hierarchical order (STRAHLER
A.N. 1964)
Stream length (Lu) Length of the stream (Horton,
1945)
Mean stream
length (Lsm)
Lsm=Lu/Nu; Where Lu=stream length of a
given order (km), Nu=Number of stream
segment
(Horton,
1945)
Stream length
ratio (Rl)
Rl=Lu/Lu-1; Where, Lu=stream length of a
given order (U), Lu-1=the total stream length
of its next lower order
(Horton,
1945)
Bifurcation ratio
(Rb)
Rb=Nu/Nu+1; Where, Nu=number of stream
segments present in the given Nu+1=number
of segments of the next higher order
(SCHUMM
1956)
RE
LIE
F Basin relief (Bh)
Vertical distance between the lowest and the
highest points of basin
(SCHUMM
1956)
Relief ratio (Rh) Rh=Bh/Lb; Where Bh=Basin relief, Lb=Basin
length
(SCHUMM
1956)
Ruggedness
number (Rn)
Rn = Bh x Dd; Where, Bh=Basin relief,
Dd=Drainage density
(SCHUMM
1956)
AE
RIA
L
Drainage density
(Dd)
Dd=L/A; Where, L=Total length of stream,
A=Area of basin
(Horton,
1945)
Stream frequency
(Fs)
Fs=N/A; Where, N=Total number of
streams, A=Area of basin
(Horton,
1945)
Texture ratio (T) T=N1/P; Where, N1=Total number of first
order stream, P=Perimeter of basin
(Horton,
1945)
Form factor (Rf) Rf = A/(Lb)
2; Where, a=Area of basin,
Lb=Basin length
(Horton,
1945)
Circulatory ratio
(Rc)
Rc = 4πA/P2; Where, A=Area of basin,
π=3.14, P=Perimeter of basin (Miller,1953)
Elongation ratio
(Re)
Re = sqrt(A/π)/Lb; Where, A=Area of basin,
π=3.14, Lb=Basin length
(Horton,
1945)
Length of
overland flow (Lg) Lg = 1/2Dd; Where, Dd=Drainage density
(Horton,
1945)
Constant channel
maintenance (C) C=1/Dd; Where, Dd=Drainage density
(Horton,
1945)
Delineation of watershed and estimation of discharge of River Shimsha using GIS 2015 - 16
Dept. of Civil Engineering, CIT, Gubbi. 42
6.1.3 Morphometric analysis – toposheet method:
Table 6.4 Morphometric parameters - toposheet method
LINEAR
Stream
Order
(U)
Stream
Length
(LU) in (m)
Stream
Length
(km)
Stream
Segments
(NU)
Mean
Stream
Length
(LSM)
Stream
Length
Ratio
(RL)
Bifurcation
Ratio (Rb)
Mean
Bifurcation
Ratio
1 962519.16 962.52 1274 0.76 3.59
4.24
2 475735.82 475.74 355 1.34 0.49 5.22
3 268543.40 268.54 68 3.95 0.56 4.00
4 101269.89 101.27 17 5.96 0.38 3.40
5 68432.81 68.43 5 13.69 0.68 5.00
6 79374.70 79.37 1 79.37 1.16
Grand
Total 1955875.77 1955.88 1720
RE
LIE
F
Basin relief (Bh) 559 m
Relief ratio (Rh ) 10.03
Ruggedness number (Rn) 848.78
Basin slope (Sb) 0.01
Constant channel maintenance (C) 0.66
Channel gradient (Cg) 6.39
m/km
AE
RIA
L
Drainage density (Dd) 1.52
km/km2
Stream frequency (Fs) 1.34
Texture ratio (T) 5.69
Form factor (Rf) 0.41
Circulatory ratio (Rc) 0.32
Elongation ratio (Re) 0.36
Length of overland flow (Lg) 0.33
Infiltration number (If) 2.03
Delineation of watershed and estimation of discharge of River Shimsha using GIS 2015 - 16
Dept. of Civil Engineering, CIT, Gubbi. 43
6.1.4 Morphometric analysis – DEM method:
Table 6.5 Morphometric parameters - DEM method
LINEAR
Stream
Order
(U)
Stream
Length
(LU) in
(m)
Stream
Length
(km)
Stream
Segments
(NU)
Mean
Stream
Length
(LSM)
Stream
Length
Ratio
(RL)
Bifurcation
Ratio (Rb)
Mean
Bifurcation
Ratio
1 739141.69 739.14 767 0.96 4.43
3.93
2 390895.88 390.90 173 2.26 0.53 4.68
3 185182.70 185.18 37 5.00 0.47 3.36
4 80977.12 80.98 11 7.36 0.44 2.20
5 84176.43 84.18 5 16.84 1.04 5.00
6 46965.34 46.97 1 46.97 0.56
Grand
Total 1527339.15 1527.34 994
RE
LIE
F
Basin relief (Bh) 559 m
Relief ratio (Rh ) 10.03
Ruggedness number (Rn) 662.81
Basin slope (Sb) 0.01
Constant channel maintenance (C) 0.84
Channel gradient (Cg) 6.39
m/km
AE
RIA
L
Drainage density (Dd) 1.19
km/km2
Stream frequency (Fs) 0.77
Texture ratio (T) 3.58
Form factor (Rf) 0.41
Circulatory ratio (Rc) 0.35
Elongation ratio (Re) 0.36
Length of overland flow (Lg) 0.42
Infiltration number (If) 0.91
6.1.5 Field visit
Field visits have been carried out in order to identify some select sample streams and outlets
for tanks. Field visits were essential to find out the present status of streams and their
existence in the ground conditions and to determine few inlets and outlets of tanks which
were found missing during the delineation process in toposheet method. Few key locations
namely, Maidala, Maralur, Gulur, Gularavi, Bheemasandra, Bugudanahalli were visited
and the present conditions of tanks were assessed and various stream orders in the network
were identified. In the next phase, a visit in Gubbi Taluk was held to identify the actual
Delineation of watershed and estimation of discharge of River Shimsha using GIS 2015 - 16
Dept. of Civil Engineering, CIT, Gubbi. 44
path of stream flow. Starting from Gubbi and covering all the tanks en route namely,
Kittadakuppe, Kadaba and Kallur tanks till the confluence point of river after Kallur.
During this visit, the highest order stream of the watershed was identified along with few
lower order stream inflows. Also we witnessed the confluence point after travelling a
distance from Kallur tank where the River Shimsha confluences with another stream
flowing from Turuvekere tank. Then the river takes the southern course and flows towards
Markonahalli reservoir and then enters Mandya District and finally joins River Cauvery.
Photographs along with geo-tagged location co-ordinates were collected from all the sites
during field visits. (Figures 6.4, 6.5 and 6.6)
Figure 6.4 Maidala Tank
Figure 6.5 6th order stream from Kadaba to Kallur tank
Figure 6.6 Confluence point of the river after Kallur Tank
Delineation of watershed and estimation of discharge of River Shimsha using GIS 2015 - 16
Dept. of Civil Engineering, CIT, Gubbi. 45
6.1.6 Rainfall analysis and yield of runoff estimation
Rain gauge stations of Tumakuru District were geo located using Google Earth. The
collected daily rainfall data were analysed and mean annual rainfalls of each stations were
determined. These were linked with the geo located stations in GIS and the mean annual
rainfall of the watershed was derived out in GIS by the method of ‘Inverse Distance
Weighting’ (IDW) interpolation. The mean annual rainfall of the watershed is found to be
666 mm. (Figure 6.7)
Figure 6.7 Heat map for the interpolation of rainfall data
Table 6.6 Mean annual rainfall and total inflow of water from rainfall for the watershed
Watershed area 1288.13 sq.km
Mean annual
rainfall over the
watershed
666.12 mm
Total inflow of
water from rainfall
85,80,55,711.39 cubic m
858.06
Million
cubic meters
30.30 TMC
Delineation of watershed and estimation of discharge of River Shimsha using GIS 2015 - 16
Dept. of Civil Engineering, CIT, Gubbi. 46
With Strange’s table as an aid, the theoretical yield of runoff from the catchment was
estimated based on the area of the catchment and mean annual rainfall over the basin and
is found to be a minimum of 3.3 TMC (93522 million litres) and an average of 4.94 TMC
(139854 million litres). The estimates of minimum and average yield are based on Strange’s
table classification of average and bad catchments respectively. (Table 6.7)
Table 6.7 Yield of runoff computation for the catchment using mean annual rainfall based on Strange's table
Type of
Catchment
Percentage
of Runoff
Yield of runoff
from
catchment (in
million litres)
Yield of runoff
from catchment
(in million litres
per day)(MLD)
Yield of runoff
from
catchment (in
TMC)
Average 16.3 139854.07 383.16 4.94
Bad 10.9 93522.05 256.22 3.30
6.2 Discussion
6.2.1 Comparison between toposheet and DEM method
The drainage delineated from toposheet and DEM methods were visually similar. Further,
the morphometric parameters were comparable and did not indicate significant variations.
Among the two methods the drainage network delineated from the toposheets was more
precise than the DEM method. This was evident from the total length of the first order
streams that was delineated, where it was 962.52 km from the toposheet and 739.14 km
from the DEM method. In this case, the toposheet method could give more precise values
since the data for the toposheet were manually surveyed using conventional instruments.
However, the DEM was derived from satellite based remote sensing that was captured at a
spatial resolution of 30m. (Figure 6.8)
Figure 6.8 Comparison of stream networks from toposheet and DEM methods
Delineation of watershed and estimation of discharge of River Shimsha using GIS 2015 - 16
Dept. of Civil Engineering, CIT, Gubbi. 47
Though the toposheet can be used to derive results at higher precision, the timeliness and
its updating can prove to be costly. The data from toposheet was surveyed during mid-
1970s, and has not been updated since then. In the case of satellite based remote sensing
despite the medium range spatial resolution of 30m, the key advantage is in its temporal
resolution (temporally repetitive). The accuracy of elevation decreases with lower spatial
resolution and vice versa. For certain spatial analysis and delineating of watershed as
carried out in this study, the data derived and results suggest that the DEM from satellite
based remote sensing can be a decent substitute for data derived from toposheet.
6.2.2 Rainfall analysis for the catchment
This study has been carried out on River Shimsha basin for an area of 1288 sq.km which is
a sub basin for River Cauvery.
The analysis of rainfall data for the period 1900-2014 indicated that the watershed had
recorded a lowest annual rainfall of 244.15 mm and a highest of 1159.48 mm (Figure 6.9).
The rainfall pattern as evinced from the graph in Figure 6.9 does depict the annual
fluctuations (variations) that are typical of such time series data. The time series analysis
was not carried out on this as this was beyond the scope of the current study. It was found
that the watershed received an annual rainfall greater than 800 mm in at least 24 instances
(years), which implies that the probability of the watershed receiving an annual rainfall
greater than 800 mm is about once in five years.
Figure 6.9 Graph indicating annual rainfall over watershed
0
200
400
600
800
1000
1200
1400
1880 1900 1920 1940 1960 1980 2000 2020
An
nu
al r
ain
fall
of
wat
ersh
ed (
mm
)
Year
Linear (Series1)
Delineation of watershed and estimation of discharge of River Shimsha using GIS 2015 - 16
Dept. of Civil Engineering, CIT, Gubbi. 48
6.2.3 Streams and morphometric analysis
Morphometric parameters clearly indicate that the contribution to water accumulation is
maximum by lower order streams (1st and 2nd order streams) and is evident that lower order
streams are essential for the existence of higher order streams such as 3rd, 4th and so on.
As the terrain is flatter with no considerable frequent undulations, the drainage density of
the basin ranges from 1.19 to 1.52 km of stream per sq. km area of the catchment. In
general, the value of the drainage density will be higher for rugged hilly and sloping
terrains. To corroborate this the drainage density of Sharavathi River basin (Sharavathi
River in central Western Ghats, Karnataka, is a west-flowing river that originates at
Ambuthirtha, Thirthahalli taluk, Shiomoga District and flows north-west for about 132 km
before joining the Arabian Sea near Honnavara town) is found to be 3.82 km of stream per
sq. km towards the western and southern catchments with rugged hills and deep valleys,
while the eastern flatter region has a drainage density of 1.54 km of stream per sq. km
(Sreekantha, et al. 2007).
Further, based on field visits it was found that inflows for a majority of lower order streams
like 1st and 2nd order streams are affected and disturbed thus affecting the inflows for higher
order streams. This is contributing to lesser inflows eventually. Since the current work
aimed at estimating the overall yield of runoff from catchment, it did not attempt to estimate
this for all micro-watersheds in the catchment.
Figure 6.10 Present state of an inflow stream to
Bheemasandra tank
Figure 6.11 Status of stream at Marlur tank outlet
Delineation of watershed and estimation of discharge of River Shimsha using GIS 2015 - 16
Dept. of Civil Engineering, CIT, Gubbi. 49
However, it was observed that the following were affecting the inflows to the stream and
catchment in general:
Urbanization in Tumakuru had led to increased water demand and consumption,
which has also resulted in significant rise in sewage generation. With the lack
of adequate sewage collection system in the city, these are often led to the
streams (Figure 6.10).
Changing cultivation pattern from dry land farming to water intensive cash
crops resulting in higher water demand. As a consequence, most runoff in the
farmlands are often retained without being let to existing streams affecting
inflows to tanks and higher order streams eventually.
Change of land-use from natural and/or agriculture to others (like built-up).
This kind of stream tampering may lead to adverse effects for both environment and
topography during the extreme weather actions which might lead for the change in course
of the river. These causes may results in high risk of life and environment.
6.2.4 Yield of run-off in the watershed
To elucidate the volume of water that needs to be managed and/or that can be potentially
harvested, a simple case on domestic water demands of Tumakuru and Gubbi urban
population are exemplified. The population of Tumakuru and Gubbi towns as per 2011
census were 3,02,143 and 18,750 respectively. Assuming the standard water demand of
135 lpcd (litres per capita per day), the total domestic water demand for these two towns is
around 44 MLD.
Considering the catchment of River Shimsha as a bad catchment as per Strange’s table
classification, the theoretical yield of 256 MLD of fresh water which can be availed from
the catchment is a significant quantity of fresh water which has to be properly used.
Although the current study did not estimate the current usage or demand from agricultural
and industrial activities, it is pertinent that these should be estimated and factored for a
better assessment of overall water demand. Subsequently water budgeting exercise could
throw light on where all (whether consumed by agriculture or evaporated or percolated or
others) this quantum of water is being dissipated. This should be used for devising a
sustainable water resource management plan.
Delineation of watershed and estimation of discharge of River Shimsha using GIS 2015 - 16
Dept. of Civil Engineering, CIT, Gubbi. 50
Chapter 7
CONCLUSION
The comparisons of toposheet and DEM methods clearly indicates that there is no notable
variations in the various results that have been derived during the study. However for
extensive studies in smaller watersheds (sub-basins, micro and mini watersheds), it is
recommended to follow the toposheets method which can yield more accurate and precise
results for water management. On the other hand, for carrying out studies for larger areas
such as state-level watershed boundaries or national watershed delineation, digital
elevation model (DEM) method with a spatial resolution of 30 m proves to be the best
solution to obtain the desired outputs effortlessly.
This study has been carried out on theoretical basis considering topographical data
(streams) from toposheets and satellite based remote sensing digital elevation model which
has revealed that a minimum of about 3.3 TMC or an average of 4.94 TMC of water can
be accumulated annually out of the Shimsha drainage basin which is a considerable quantity
of water.
In order to harness this theoretically estimated yield, there is a greater need for conservation
of lower order streams (particularly 1st and 2nd order) and protect them from encroachments,
breaches and interferences. It is also essential to recover most of the streams which are in
the deplorable state as discussed earlier.
As the rainfall over this basin is predominantly through monsoon rainfall, the rain water
has to be efficiently stored either in available storages like tanks, wells and by recharging
ground water table or artificially stored in reservoirs to utilize the water for various
purposes all-round the year. This calls for the proper maintenance and recovery of the tanks
by scientific de-silting as these storages are readily available.
Conservation of these lower order streams becomes very important in order to ensure the
flow of water from these streams to the higher order streams and tanks or other storage.
This would ensure efficient accumulation and storage of water in the catchment.
Delineation of watershed and estimation of discharge of River Shimsha using GIS 2015 - 16
Dept. of Civil Engineering, CIT, Gubbi. 51
7.1 Scope for future work
Based on the current study, a theoretical estimate of the yield of runoff suggests a
significant volume of water in the catchment. In order to properly utilize the available
natural water resource a detailed investigative study has to be conducted and the streams
have to be restored in order to accumulate the estimated quantity of water.
The present work carried out can aid for further studies on the Shimsha watershed and help
planning for a sustainable water resource management. There is scope for detailed studies
on the following which might assist for water resource management of Tumakuru district.
Cause for interruptions in the stream network and status of the tanks in the
watershed.
A detailed study on water budgeting factoring the current consumption by
different uses and also estimate losses (through evaporation, transpiration,
infiltration, others like depression storage).
A detailed estimation of cost for rejuvenation of streams of various order.
A detailed study with land use and land cover remote sensing data to investigate
the changes in usage of land and action for recovery of streams.
Apart from all these it is critical to create and raise awareness on the need for
sustainable water resource management.
Delineation of watershed and estimation of discharge of River Shimsha using GIS 2015 - 16
Dept. of Civil Engineering, CIT, Gubbi. 52
REFERENCES
Abhishek, Bothra, Khadka Anish, and S, R Vikas. 2014. “Morphometric Analysis of
Watersheds in the Kunigal Area of Tumkur District, South India Using Remote
Sensing and GIS Technology.” Acaademic Project, Tumkur.
NungshichilaLongchar, Manjunaik, Praveenkumar, and Chaya G. 2014. “Water Resource
Management in Hassan District using ArcGIS.” Hassan.
Amanda, Briney. n.d. Stream Order: A Classification of the Rank of Streams and Rivers.
Accessed May 2016.
http://geography.about.com/od/physicalgeography/a/streamorder.htm.
K, C, Patra. 2008. Hydrology and Water Resources Engineering. 2nd. Orissa: Narosa
Publishing House Pvt. Ltd.
K, Subramanya. 2008. Engineering Hydrology. 3rd. New Delhi: Tata McGraw Hill
Education Private Limited.
Anupama, Pai. 2004. An Introduction to Maps. Pondicherry: Foundation for Ecological
Research.
Otto, Huisman, and By Rolf A.De. 2001. Principles of Geographic Information Systems.
The Netherlands: The International Institute for Geo-Information and Earth
Observation.
Deputy Commissioners Office, Tumakuru. n.d. General Information: Location and Aspects
of Tumakuru District. Edited by Govt. of Karnataka. National Informatics Centre.
Accessed March 2016. http://tumkur.nic.in/.
Karnataka Water Resources, Department. n.d. River Systems of Karnataka. Govt. of
Karnataka. Accessed March 2016.
http://waterresources.kar.nic.in/river_systems.htm.
Office of the Chief Engineer, Minor Irrigation. 1990. Minor Irrigation Manual. Bangalore,
Karnataka: Irrigation Department, Govt. of Karnataka.
NARENDARA KUMAR, J.N, and Prof. Dr.TG SITHARAM. 2011. “The Application of
GIS & RS – A case study of Vrishabhavathi River/ Valley Drainage pattern.”
CiSTUP,IISc.
Delineation of watershed and estimation of discharge of River Shimsha using GIS 2015 - 16
Dept. of Civil Engineering, CIT, Gubbi. 53
Prapul, K, S, B, D Roopali, A, R Sowjanya, and Y, V Yogitha. 2014. “Rainwater Routing
by Using GIS Application.” Academic Project, Bengaluru.
SCHUMM, S.A. 1956. “Evolution of drainage systems and slopes in Badlands at Perth
Amboy.” New Jersey. Bull. Geol. Soc. Amer. 67: 597-646.
Sreekantha, M.D. Subash Chandran, D.K. Mesta, G.R. Rao, K. V. Gururaja, and T.V.
Ramachandra. 2007. “Fish dIversity in relation to landscape and in central Western
Ghats, India.” Current Science 92 (11): 1592-1603.
STRAHLER A.N. 1964. Quantitative geomorphology of drainage basins and channel
networks. New York: McGraw-Hill.
Wikipedia. n.d. Shimsha. Accessed March 2016. https://en.wikipedia.org/wiki/Shimsha.
—. n.d. Strahler number. Accessed March 2016.
https://en.wikipedia.org/wiki/Strahler_number.
SCHUMM, S.A. 1956. “Evolution of drainage systems and slopes in Badlands at Perth
Amboy.” New Jersey. Bull. Geol. Soc. Amer. 67: 597-646.
Hajam, R. A., Aadil, H., & SamiUllah, B. (2013). Application of Morphometric Analysis
for Geo-Hydrological Studies Using Geo-Spatial Technology –A Case Study of
Vishav Drainage Basin. Journal of Waste Water Treatment & Analysis, 04(03), 1–12.
http://doi.org/10.4172/2157-7587.1000157
Horton, R. E. (1945). Erosional development of streams and their drainage basins;
Hydrophysical approach to quantitative morphology. Bulletin of the Geological
Society of America, 56(3), 275–370. http://doi.org/10.1130/0016-
7606(1945)56[275:EDOSAT]2.0.CO;2
Morphometric Analysis of Tungabhadra Drainage Basin in Karnataka using Geographical
Information System. (2013), 2(7), 1–7.
Waikar, M., & Nilawar, A. (2014). Morphometric analysis of a drainage basin using
geographical information system: a case study. International Journal of
Multidisciplinary and Current Research, (2012), 179–184. Retrieved from
http://ijmcr.com/wp-content/uploads/2014/02/Paper32179-184.pdf
Delineation of watershed and estimation of discharge of River Shimsha using GIS 2015 - 16
Dept. of Civil Engineering, CIT, Gubbi. 54
Project team: Digital Cartographers
Sl.
No. Name of Student Email Id
1. Mr. Bharata H S [email protected]
2. Mr. Darshan K H [email protected]
3. Mr. Pavan S [email protected]
4. Ms. Spoorthy Sadashiv
Shanubhog [email protected]