Watershed problem and management ; study on Khulna University,Bangladesh

Presentation On Watershed Survey

Course Title: Watershed Management Sessional / Field work

GROUP: B

Watershed Objectives of watershed survey. Measurement areas in a watershed Buildings, roads and other constructions of Khulna

University Water bodies of Khulna University Vegetative areas of Khulna University Survey results Problems to the watershed of Khulna University area Overall condition of Khulna University Watershed.

CONTENTS

“

Watershed

A watershed, also called a drainage basin or catchment area, is defined as an area in which all water following into it goes to a common outlet.

It can be defined as a unit of area that covers all the land which contributes runoff to a common point

What is watershed?

The area of land that drains water, sediment, and dissolved materials to a common outlet at some point along a stream channel”.(De Barry)

According to FAO (1986) “Watershed is a topographically delineated area that has drained by a stream system i.e. the total land area that is drained to some point on a stream or river”.

Watershed

To know how to estimate the watershed of any given area.

To know the drainage condition of the area. To know the health of the vegetation . To identify watershed problems and potential

sources of pollution. To determine the possible cautions to preserve

watershed. To help in proper management of watershed.

Objectives

To know the features of watershed Carrying capacity assessment Health assessment of watershed Risks assessment of watershed Planning and design Implementation Monitoring Readjustment of the plan of monitoring

Objectives

Vegetation: Including trees, grasses, It prevents soil erosion and land degradation

Topography Soils: Drainage system, water holding capacity,

texture all the properties control watershed Water body: Main component of watershed.

Pollution of water is responsible for changing ecosystem and environment. Propagation of fishes and other aquatic animals depends on water body.

Components of watershed

Functions of watershed

Watershed function

ecological function

hydrological function

Confluence function

water conservation function

regulating function

the function of chemical transport

Habitat function

The Watershed of Khulna University area

KHULNA UNIVERSITY

Areas to be measuredTo measure the watershed of any area, the following area measurements are required

Concrete Surface.• Roads• Buildings• Other

constructions

Vegetative Land.• Forest• Grass land• Bare field• Fallow Land• Agricultural

land

Water Body• Lakes• Ponds• Canals• Rivers

Concrete Surface

Water Runoff

Disturbance in recharging groundwater

Concrete Surface

Concrete surface or Runoff areas of Khulna University

Roads

Buildings

Other constructions

Roads

Roads

Roads

Roads

19

Design of Roads

Road Area(sq. meter)Brick road from Aparajita hall to teachers’ quarter

1824

Brick road to employees building 272Brick road beside Khan Bahadur Ahsanullah Hall

1000

Brick road in front of Bangabandhu hall

1032

Pucca road from Khanjahan Ali hall to Aparajita hall gate

4632

Pucca road from KU lake to Aparajita hall gate

80

Pucca road from KU main gate to Hadi Chattor

3048

Pucca road in front of KU Medical 152Brick road in front of Khan Bahadur Hall

648

Pucca road in front of bus stand 324

Area measurement of roads

Road Area (sq. meter) Cafeteria road 164Pucca road(s) from administration building to teachers quarter

2368

Brick road beside teachers quarter

868

Brick road to the play ground 128Brick road beside administration building

1152

Brick road beside post office, bank

268

Brick road beside bank 144Brick cover beside 2nd academic building

448

Brick road in front of Adammo Bangla

1056

Brick road from central library to the back of 2nd academic building

2088

Area measurement of roads

Problems to the roads (Erosion)

Problems to the roads

Moderate to severe surface erosion Road Shoulder erosion Direct flow to water body

Problems to the roads

BUILDINGS

BUILDINGS

The buildings and constructions have a negative

effect on a watershed.

The clearing of vegetation due to construction, leads

to erosion. Building materials are also washed into the

water bodies. This has an adverse effect on stream and

river health too.

Buildings

Measurement of BUILDING AREABuilding Name Area (sq.m)Academic Building- 1 2580Academic Building -2 5432Academic Building -3 5040Khan Jahan Ali Hall 2980Khan Bahadur Ahasanullah Hall

2800

Aparajita Hall 6012Shaik Mujib Hall 2980Caféteria 532Central Mosque 360Motor Cycle Stand 130Primary School 280BNCC Office 105Purnendo Gain Lab 72

Measurement of Building AreaBuilding Name Area (sq.m)V.C Banglo 244Stuff Quarter - 1 580Stuff Quarter - 2 600Sharli Islam Library 415Central Library 2556Adohmmo Bangla 144Shahid Miner 120New Bank 85Administrator Building 2292Post Office 80Agroni Bank and KU Studies 288

Measurement of Building AreaBuilding Name Area (sq.m)Teachers Quarter - 1 180Teachers Quarter - 2 185Mukto Mancho 155Medical Office 256Agro-technology lab - 1 240Agro-technology Lab - 2 240Green House 54Police Fary New 205Forestry Lab - 1 245Forestry Lab - 2 244Roterate office 72

Run off after precipitation Roof run off causing erosion Improper ground water recharge

Problems due to buildings and constructions

Total area of roads : 5.359 Acres. Total area of buildings and other

constructions :8.50421 Acres. So, total runoff area is 5.359+8.50421=13.8632 Acres

SURVEY RESULT

Water Body

Crucial part of a watershed.Consists mainly of

Water Body

Lakes Ponds

Channels Rivers

Seas Ocean

Ponds

Water Body

Water Body

Water Body

Map of water body

Survey Area Name Area(m2)

Pond of Khan Bahadur Ahsanullah Hall

2368

Frontage pond of Khan Bahadur Ahsanullah Hall

576

Ponds behind the Khan Jahan Ali Hall

1728

Central library(frontage side) pond (small)

360

Canal behind the 3rdaceademicbulding

3712

Pond Behind the quarters 1272

Fisheries' area beside the 2nd academic building 4340

Pond(small) behind the Odommo Bangla monument

3311

Fisheries area beside the 1st academic building

3358842

Pond behind the Aporajita Hall 1356

Pond beside the Mosque 2688

University lake 14776

Total: 40075

The total area of water body = 9.899 Acres.

Survey Result

Disturbance and pollution

Moderate to severe erosion Ditch erosion Throwing plastics, bottles, garbage etc to the paths of

water flow Filling the water channels with sediments and waste

materials.

Problems to the water body

Vegetative Area

Another inseparable element in any watershed is vegetation.The vegetation in watersheds have impacts on The quality of the water Reducing sedimentation Wildlife and bird habitat, Soil health. Air quality, etc. Grasses, shrubs, and trees make up the majority of plant

cover . As leaves fall and decompose, they add the organic matter to the soil

Vegetative Area

Vegetative Area

Vegetative Area

Total Vegetative area =81.8378 Acres.

Survey result

Pollution

Slight or moderate surface erosion Direct flow or runoff to water bodies Throwing various waste materials Using some forest grounds as parking lot.

Problems to the vegetative land

Satellite map of Khulna University

Ridge line

Sub Stream

Outlet

Main Stream

Figure-1: Watershed in river basin with sub stream

Sub Watershed

Sub Watershed

Sub Watershed

Sub Watershed

Main channel

Sub channelSub channel

Sub channel

Outlet

Figure-2: A watershed with sub watershed and sub basin

Play ground and

Agricultural land of Khulna

University

Components Area (acre)Water Body 7.319

Building 9.408

Road 5.359

Vegetative land 81.40

Total area 105.6

Coverage Area

7%9% 5%

79%

Area DistributionWater Body Building Road Vegetative Land

RIVER

Main Channel(Lake)

Agricultural

Field

PLAY GROUNDPOND

DRAINAGE

AGRICULTURAL FIELD

Pond

Lake

Khulna University area possesses sub parallel and radial type of watershed

Result

The End