INTRODUCTION TO TOPOSHEETS-45D/7 AND 45D/10

PROFILE OF SURVEY MAP 45 D/7

DESCRIPTION of the Area covered by Survey Sheet No. 45 D/7 (Gujarat and Rajasthan)

District : Banas Kantha and Sirohi Location: Latitude 24 degrees 15 24 degrees 30 North Longitude 72 degrees 15 - 72degrees 30 East This region lies in western India on the borders of Rajasthan and Gujarat at the

southern end of the Aravalli Hills,

immediately north-east of Sheet 45 D/10.

RELIEF The area is mainly a plain except for: 1. The east central region where the hills rise to almost 500 m.,

2. The lower hills of the north-east corner. The slope of the land is from north-east to south-west in the northern half and east to

west in the southern portion of the map. (indicated by flow of rivers) DRAINAGE 1. The Banas river (not to be confused with the Banas river which is a tributary of the

Chambal river to the north) flows into the swampland area of the Little Rann, north-east of the Gulf of Kutch. On this survey sheet it

flows westward. It has two main right bank tributaries Sarod and Arado Nadis and the numerous smaller streams like the one entering the river near Chekla (8192). The

only left bank tributary is the Balaram Nadi from the south-east. The Banas river varies in width from 1/4km to over 1 km and has a

narrow perennial water course. The dry portion fills in during the rainy seas.

2. The Sipu Nadi is a tributary of the Banas river (the confluence) lying to the west of the area shown. It flows from north-east to south-west withits two main tributaries Varka and Mahadeviyao Nadis joining the left bank. Both rise in the hilly region to the east.

In the region there are numerous other

streams that join main rivers. They rise in the higher ground adjacent to the rivers and

invariably their courses show large tracts of broken ground indicating soft soil easily eroded by water.

SOILS Map symbols indicate desert conditions, a large part of the plain area being sandy. Soils

are soft as shown by excessive erosion causing broken ground near water courses.

CLIMATE There are three climatic seasons: Summer-- hot and dry-- March to June Monsoon-- hot and wet --July to September

Winter-- cool and dry --October to February Maximum temperatures in summer are

extremely high rising to over 470 C, while minimum temperatures in December/Jan often drops to almost 0 degree C. Because of its location in western India, it receives

comparatively less rainfall than other parts of the country. The rainfall which is between 50 to 100 cm annually, falls during the monsoon

season. High temperatures cause excessive

evaporation. This gives rise to scrub and semi-desert vegetation.

NATURAL VEGETATION Hill areas dry deciduous forests of small trees Plains scrub and throny trees where there is no agriculture.

IRRIGATION This region is dependent on the periodic rainfall (Monsoon), tanks, wells for agriculture. There is only one canal in the

north-east starting from the reservoir (2222)

OCCUPATIONS

Agriculture, rearing of cattle, sheep, camels and horses. CROPS: Winter (Rabi) Wheat, Barley, Cotton Monsoons (Kharif) Bajra, Jowar, Maize

COMMUNICATIONS

Except for the main line of the Western Railway and the road that runs across the

south-east corner of the map through Chitrasani (8923), there are no other important communications. All other settlements are linked by cart tracks.

SETTLEMENTS Except for Chitrasani which is a rail/road centre, all the settlements are small and

widely scattered chiefly in the lowland area and are either nucleated or dispersed in pattern.

PROFILE OF SURVEY MAP 45 D/10

DESCRIPTION of the Area covered by Survey Sheet No. 45 D/10 (Gujarat and Rajasthan)

District : Banas Kantha and Sirohi Location: Latitude 24 degrees 30 24 degrees 45 North Longitude 72 degrees 30 - 72 degrees 45 East

This region lies in western India on the borders of Rajasthan and Gujarat at the

southern end of the Aravalli Hills, immediately north-east of Sheet 45 D/7.

RELIEF The sheet is divided into two distinct physical divisions: 1. The Aravalli Hills rising to a height of over

1400 meters and occupying the south-east corner. The ranges are more or less parallel and run in a NE to SW directon.

2. A large plain covers the remaining portion of the sheet. There are frequent outcrops of

rocky ground, some of it rising to over 400 m (i.e. 100 m above the surrounding country side.)

DRAINAGE In the hill area, the drainage is radial. Abu being the highest point of the area is the centre from which the rivers radiate. In the

plains, the upper courses of the rivers are dendritic or fan shaped. The main stream Sipu Nadi rises in the hills north of Abu and

flows in a south-west direction. It is periodic and seldom exceeds km in width.

TRIBUTARIES: Right bank : Sukli Nadi, Unda Wala, Dior Nadi, Left bank: Sukli Nadi, unnamed river flowing

past Dhavli, Devengan Nadi and Godua Nadi NOTE:

1. There are three Sukli Nadis in the survey sheet. 2. Because this regions lies close to the

desert areas where the soils tend to break up easily, the water courses are numerous and well defined for they are able to cut channels in the soft sandy soils. They are however

periodic and rely on the rainy season for the water supply.

CLIMATE There are three climatic seasons: Summer-- hot and dry --March to June

Monsoon --hot and wet-- July to September Winter-- cool and dry --October to February

Maximum temperatures in summer are

extremely high rising to over 470 C, while minimum temperatures in December/January

often drops to almost 0 degree C. Because of its location in western India, it receives comparatively less rainfall than other parts of the country. The rainfall which is between 50

to 100 cm annually, falls during the monsoon season. High temperatures cause excessive evaporation. This gives rise to scrub and

semi-desert vegetation.

NATURAL VEGETATION Hill areas dry deciduous forests of small trees Plains scrub and throny trees where there is no agriculture.

IRRIGATION This region is dependent on the periodic rainfall (Monsoon), tanks, wells for

agriculture. There is only one canal in the north-east starting from the reservoir (2222)

OCCUPATION Agriculture, rearing of cattle, sheep, camels and horses.

CROPS: Winter (Rabi) Wheat, Barley, Cotton Monsoons (Kharif) Bajra, Jowar, Maize

COMMUNICATIONS Abu, in the hill area, is linked eastwards by two main roads, which run south-east to Abu

Road and north-east to Oriya. In the south of this region the east-west main road links up at Karaunti (0700) with another main road which runs parallel to the foot-hills and

connects a number of settlemtns. Many of the smaller settlements are linked by cart tracks.

SETTLEMENTS Abu is a large hill resort, an administrative and an educational centre. In the plains, there are numerous settlements of much

smaller size of which Sirori (2023) is the most important.

Important Definitions on Topographical Maps

IMPORTANT DEFINITIONS FROM TOPOGRAPHICAL MAPS

REPRESENTATIVE FRACTION (RF): It is the ratio between the distances on the map to its corresponding distance on actual ground. The RF on this map is 1:50,000. 2. SCALE : Scale is the ratio between the distance of any two points on the map and the actual distance of the same points on the ground.

The scale of the given map extract is 2 cm: 1 km or 1:50,000. 3. CONTOUR: Contours are imaginary lines drawn on maps, joining all places with the same height above sea level. 4. CONTOUR INTERVAL: The interval between two consecutive contours is called contour interval (*it is a constant 20 mts in your toposheets.) 5. INDEX CONTOUR: Contour lines are thickened at regular intervals to make it easier to read contours. For example at every 100 mts the contour line is made darker. The darker lines are called Index Contours. 6. TRIANGULATED HEIGHT: It is the height of a place which has been calculated using

trigonometry, represented by a small triangle e.g. - 540 7. SPOT HEIGHT: The height of random places between contours shown with a dot. Eg - .425 8. BENCH MARK - Height of a place actually marked on a stone pillar, rock or shown on a building as a permanent reference. It is written as BM 200 m. 9. RELATIVE HEIGHT: Relative height is the height of a feature with reference to the height of the surrounding land and NOT to sea level. It is represented by the height with a small r eg 12r. 10. ROCK OUTCROP: It is a portion of rock jutting above the surface of the earth. 11. SHEET ROCK: Large areas of rock where the overlying soil layers have been eroded and removed due to mechanical weathering. 9 STONY WASTE : A large area usually in arid/semi arid regions where the finer sand/soil has blown away leaving a surface covered with boulders, stones and pebbles.

10. BROKEN GROUND: A relief feature found mostly in dry regions around rivers and streams. It is land around river, which is totally weathered (exfoliated) due to alternate cooling and heating. 11. FIRELINE: A cleared pathway in a forest to prevent the spread of forest fires. 12. MIXED FOREST: A forest with more than two varieties of trees growing in close proximity to each other. 13. OPEN JUNGLE: A forest where trees are widely scattered. 14. DENSE JUNGLE. : A forest where trees grow very close to each other. 15. OPEN SCRUB: Scrub is a vegetation found in regions with less than 100 cms of rainfall. Therefore it indicates a dry region. 16. BRACKISH: It is a well, which has water with very high salt content generally unfit for drinking purposes. 17. CAUSEWAY: It is a raised road over a small water body. (Usually a road used only in the non rainy months.} 18. CUTTING: A portion of land, which has been cut in order to make land available for transport routes. (it is indicative of a rocky region) 19. EMBANKMENT: They are raised rock or soil filled constructions on which roads/railway tracks are built. Also made near tanks and rivers to prevent flooding.

20. FORM LINES: Form lines are contour lines, but show only approximate heights above sea level as they are used to indicate the elevations of the area which are not accessible for proper survey. Hence they are drawn as broken lines and are called 'form lines'.

21. Q.C. Q.D., OC, OD,PQ, ETC : These are alphabetical codes used to represent the biggest grid sq. of 10,000 square kms.

The Govt of India has adopted metric system for all measurements. All the ordnace survey maps issued by the Survey of India were drawn to the scale 2 cm = 1 km. In this system , the surveyed territory is divided into 100km X 100 km squares, and each square is denoted by English alphabets. for example, OC, OD, PQ, PG, etc . This system of map drawing is known as National Grid Reference.

22. LAYER TINTING: (colouring) While spot heights show the height of the land, they only do so at certain points. To provide an overall image which conveyed height, a technique called layer tinting was developed. Layer tinting uses different colours (or shades) to represent different heights. It is a mapping convention for darker colours to signify greater height. When using layer tinting, green is often used for low land, yellow for higher land and brown

for the highest land. Layer tinting is most commonly found on physical maps. While layer tinting is useful, it does not show the detailed shape of the land.

23. DEP: It is a depression often found in sandy areas where the wind, having blown away the sand, leaves a hollow or a depression.

24. HACHURING: Early cartographers attempted to show surface features on maps by using the technique of hachuring. Hachures use short lines of varying thickness to show the shape and slope of the land. In accordance with this technique, the steeper the slope is, the thicker the lines are which represent it. While hachuring was initially innovative for its time, it gradually began to be replaced since the actual height of the land was not depicted.

25. LIME KILN OR BRICK KILN: These are open furnaces where limestone is purified or bricks are baked for construction purpose.

26. HILL SHADING: Hill shading resembles a light and shadow effect. Valleys and the sides of mountains appear as though they are cast in shadow. This is a visually striking method, which is ideal for providing an overall view of the relief of an area. Hill shading, however, does not show height which means that it is no more accurate than hachuring.

Significance of colour on Toposheets SIGNIFICANCE OF COLOURS IN TOPOSHEETS On toposheets colours are used to show certain features. Each colour used on a map has significance. 1. BLACK All names, river banks, broken ground, dry streams, surveyed trees, heights and their numbering, railway lines, telephone and telegraph lines, lines of latitude and longitude 2. BLUE Water features or water bodies that contain water. 3. GREEN All wooded and forested areas, orchards, scattered trees and scrubs. Note:- Prominent surveyed trees are shown in black. Surveyed trees have numbers on their trunks. They serve as landmarks and are not allowed to be cut. 4. YELLOW All cultivated areas are shown with a yellow wash. 5. WHITE PATCHES Uncultivable land 6. BROWN Contour lines, their numbering, form lines, and sand features such as sand hills and dunes 7. RED Grid lines (eastings and northhings) and their numbering, roads, cart tracks, settlements, huts and buildings. SETTLEMENTS 1. On a topo map, all settlements are shown by symbols in RED colour. 2. The size of the symbol and size and style of letters used give an idea of the size of the settlement. 3. In the case of large cities, major roads are marked and named. 4. Deserted village cities, temporarily occupied huts are also shown. 5. Places of worship, forts, water towers, burial grounds, police stations, post office, dak bungalow, circuit houses, etc. are indicated by suitable symbols. NOTE Site is the land on which the settlement (village or town) is built. Dense settlements : Fertile plains and wide river valleys. Sparse Settlements : forests, deserts, mountain slopes, plateaus and hill tops with poor vegetation Absence of Settlements: Swamps, marsh land, sandy deserts, thick impenetrable forests, flood-prone areas, steep mountain slopes. OCCUPATION AND MAP FEATURES

AGRICULTURE Level land with yellow wash; many wells LUMBERING: Forests CATTLE REARING Pastures, meadows, grasslands, presence of road in highland region (sheep) FISHING Plenty of rivers MINING Stony wastes, quaries, limestone beds TRADE Dense settlements near road INDUSTRY Large settlements near roads and railways, presence of raw materials, (like making, cement industry near limestone beds) TOURISM hotels and inns APPROXIMATE OR RELATIVE HEIGHT This height is not taken from sea level but with respect to the surrounding area. It may be the height of a dam, bridge, sand dune or it can be the depth of a well, tank, hill or river canal, for example , 3r, 5r, 8r, etc. EXAMPLE: 3r - the relative depth of perennial lined well in 3 metres 3r 5r the relative height of dry tank is 5 metres 5r NOTE: CHECK THE SYMBOL if it is tank, dam, bridge, embankment, etc then write the answer this way - the relative height of .............................. is ................meters.

Other Interpretations on Topographical Maps

Man-made and Natural Features

Toposheets shows various details of an area- natural and man made features by means of conventional signs(legends), contours and pictorial diagrams in conventional colours. Natural features rivers, streams, sand features, trees, broken grounds, natural ponds, unlined wells, jungles, depresions (Dep), islands (in the exposed river beds), physical features like hills, waterfalls, spurs, river valleys and cliffs, shown by contours and their heights. MAN made features surveyed trees, queries, permanent huts, causeways, mines, metalled and unmetalled roads, pack tracts, cart tracts, artificial lakes with embankments, boundaries (national and international), post offices, police chowkies and inspection bungalows.

Means of Transport in Relation to Relief

Transport always depend on the type of relief and drainage Eg. Very high altitudes, mountaineous areas-only roads and no railway tracks- difficult to build at such heights On the map-roads are shown by means of symbols of cart tracks, pack tracts, metalled roads, unmetalled roads, footpaths with a bridge. Main towns- well connected by metalled roads show economic development of the area-is the indication of trade being carried on. Hence town shows well developed. Causeways are raised platforms across a dry stream. During dry season when the stream dries up, people make a habit of crossing it. Thus, a footway is formed. Presence of many causeways shows that the area gets seasonal or scanty rainfall.

DIRECTIONS

Directions- important tool while reading topo map. Directions are important for physical as well as urban features. Physical features- directions of rivers, streams, Urban cities from one another

DIRECTION-TO RIVER AND RIVER BANKS

Need to know which direction river flows. REMEMBER THESE STEPS: 1.First look at the spot heights to determine the slope of the land 2.To know which side/bank of the river a place is situated, one has to locate the source of the river. Having located the direction of the river, imagine yourself standing at the source of the river facing the main river facing the main river. Now to your right is right bank and to your left is the left bank.

Calculation of Area

Area= Length x Breadth In topo maps, each grid (square) 2cm X 2cm or 1 km to 1 km as per the scale 2 cm=1 km Therefore , area of each square is 4 sq cm (on the map)= 1 sq km (on the ground) In metres, this can be expressed as Area of each square (i.e. 4 sq cm) = 1000 X 1000 or 1,000,000 sq m.

To calculate the area by grid square method: If there are some incomplete squares, area can be calcualted as follows: -Note the number of completed squares -Squares covered half are taken as -Squares covering less than half area are taken as 1/3 -Squares covering more than half of the area are taken as 2/3 -All these estimated squares are added together and the sum is multiplied by the scale of the area given out above to obtain the desired area.

LAND USE

IN topomap location of veg is closely related to relief. In the highlands, vegetation is shown green colour along with contours in brown showing elevation. To show density of wooded area, different terms used: Dense forest, open-mixed forest, open jungle, fairly-mixed jungle, dense-mixed jungle, mixed jungle, Reserved Forest (RF), Protected Forest (PF), fairly mixed jungle with bamboo, dense mixed jungle with bamboo. The exterior boundaries of areas of Reserved or Protected forest are shown by green ribands .

THE PLAINS:- Plains-mainly agriculture- cultivable land is shown in yellow colour White patch in plain shows bad land or rocky, uncultivable land. In such land, following features are found- Open scrub scrub land where mostly sheep and goat rearing is practiced Stony waste the land which is mostly covered with rock boulders and stones and cultivation is not possible.

SHEET ROCKS:- Sheet rocks a region mostly covered with a sheet of rock. Rock outcrop In such region subsoil is exposed and cultivation is not possible. Broken ground developed because of absence of natural vegetation on both the banks of the river. It is common in the desert area and in the areas of gully erosion.This is formed due to floods which occur during rainy season. Because of floods, the top soil is washed away developing into bad land which has loose soil and is uncultivable.

LOW LANDS:- Plains which are situated at lower level are mostly characterized by a meandering river. A disappearing stream shows a desert or limestone area

Presence of canal, wells, tube wells and tanks indicate use of land for agriculture by means of irrigation A meandering river shows a flat area Perennial lined wells indicate a higher water table and are shown by blue dots.

Presence of dry streams, dry ponds, exposed river beds and broken land shown in black indicate an area with scanty rainfall or seasonal rainfall or a desert region. Settlements are generally found on either side of river-wherever irrigation by canals or perennial lined wells is available

MEANS OF IRRIGATION

Irrigation largely depends on relief and land use pattern of area (blue) Hilly region- no cultivation is possible, hence there is no need for irrigation On the flat lands which are coloured yellow, one can see blue, round spots which represent perennial lined wells. therefore one can say that the main source of irrigation in such areas are wells and the occupation of people is farming. Other means of irrigation are canals, ponds, artifical lakes withj embankments and river in case it is perennial. Presence of dry streams and dry ponds with uncultivable lands shown in white indicates that the rainfall in the area is scanty. Presence of artificial man-made lake with embankment shows that water is being stored in off season and is used for irrigation through canals.

OCCUPATIONS

Occupations have to be inferred from toposheets as there are no symbols to show the occupations of people. Sometimes, certain names like farms, orchards provide some evidence of these occupations. The following list gives you some information about occupation of the

people from a topo-sheet.

OCCUPATIONS EVIDENCES Forestry, lumbering Forest or Green Patch Agriculture Yellow Patch or orchards with many wells Cattle-grazing or sheep rearing Meadows or Scrub, grasslands, meadows, pastures Quarrying and mining Mines and Quarries, lime stone beds Trade Settlement near main roads, ports, rivers, etc dense

settlement Entertainment & Cultural devpmnt Gold Courses, Parks, Rifle Ranges, etc Industry Factory, mines, large settlements near roads and

railways, presence of raw materials (lime making and

cement industry near limestone beds) Fishery Coast,l akes, rivers, etc Tourism Hotels and Inns

Thus, the occupation of the people of an area can be inferred from the following : Topography of land Size of settlement Presence of quarry and mines Communication network indicating trade

REMEMEMBER FEW POINTS:

HACHURING: Hachuring are short lines representing directions of a slope. For steep slopes they are drawn closer together than for the gentle slopes. However on flat ground, they cannot be used.

SPOT HEIGHTS: Spot heights are used to provide more information about land surfaces between the contours. These are represented by a

number preceded by a dot. for example 340

TRIANGULATION POINTS: When the spot heights are accurately surveyed

, the dot is enclosed within a triangle and are called the triangulation points.

BENCH MARKS: The marks inscribed stones or shown on buildings to indicate the exact height determined through the surveys, are called the Bench Marks. These marks are shown by letters BM along with height . eg. BM 590

INDEX CONTOURS: To make the maps easier to read, contour lines are thickened at regular intervals. These thickened contour lines are called index contours.

FORM LINES: These are broken lines between contour lines to indicate minor details. They show approximate heights above sea level as they are used to indicate the elevations of the area which are not accessible for proper suvey.Hence they are drawn as broken lines and are called 'form lines'.

TRIGONOMETRICAL STATIONS: These points show height and are marked by a triangle and height. eg. 877