UNIT- 1INTRODUCTION TO WATER

RESOURCESENGINEERING

STAFF: Vijaya Kumar R

Water resources engineering 15CE52T

V sem civil

INTRODUCTION:-

• Of all the planet’,s renewable resources, water has a unigue place. It is essential for sustaining all forms of life, food production, economic development, and for general well being. It is impossible to substitute for most of its uses,difficult to de-pollute,expensive to transpoitgand it is truly a unique gift to mankind from nature. Water is also one of the most manageable of the natural resources as it is capable of diversionttranggort.storage. and recycling. All these properties impart to water its great utility for human beings. "

WATER RESOURCES DEVELOPMENT

• lndiais rich in Water resources, being endowed with a Network of great rivers and vast alluvial basins to hold ground water Conditions, however, vary Widely from region to region. Whereas there are some chronically drought affected areas, there are others which are frequently subject to damage by floods. On the whole, under the pressure of rapid population growth, the available resources of water are being developed & depleted at a fast rate & the situation seriously underlines the need for taking up integrated plans for water conservation & utilization for every agro-ecological area to meet the increasing demands of irrigation, water harvesting, human & livestock consumption, expanding industry, hydro-electric power generation, recreation, navigation & other uses.

• PTO

In general, sustainable Development of water resources necessary due to following reasons

> Increase in water requirements due to increase in population.

> Easily available sources of water tapped already.

> Delay in project initiation time due to increase in social and environmental concern.

> Contamination of available water sources due to increase in human activities.

> Industrial development.

The water resources development projects are planned to serve the following purposes

1) Irrigation

Objective : Agriculttual production.

2. Domestic and industrial water supply

Objective: Provision of Water for domestic, industrial, commercial, municipal, and other uses.

3)Flood control

Objective : Prevention or reduction of flood-damage, protection of economic development,

Hydroelectric power

Objective: Generation of electrical power for economic development and improved living standards.

Navigation

Objective: Transportation of goods and passengers.

Watershed management

Objective: Conservation and improvement of soil, sediment abatement (reduction), runoff retardation, forests and grassland improvement, protection of water supply.

Recreational use of water

Objective: Increased well being and health of people.

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Drainage

Objective: Agricultural production, urban development, protection of public health. The various works and measures: Ditches, tile drains, levees, pumping stations, soil treatment.

Sediment control

Objective: Reduction or control ofysilt load in streams, protection of reservoirs.

SALINITY CONTROL

POLLUTION ABATEMENT

ARTIFICIAL PRECIPITATION

WORLD WATER RESOURCESFor proper control and use of water it is essential to have an idea of availability of water-

1. Saline Water (Oceans & sea)- 97.3%

2. Fresh Water — 2.7%

1. Polar Ice Caps- 77.2%

2.Ground Water & Soil Moisture-22.4%

3. Lakes, Swamp & Reservoirs- 0.35%

4.Atmosphere- 0.04%

5.Rivers & Streams- 0.01%

WATER RESOURCES OF INDIA

India, with a geographical -area of 329 Mha (million hectares), is blessed with large river basins which have been divided into 12 maior and 48 medium RIVER BASIN comprising of 252.8 Mha and 24.9 Mha of total catchment area, respectively. It possesses about 4 per cent of the total average annual runoff of the riversof_tlle world. The per capita water availability. of natural runoff_is, however, only 2,200 cubic metre per year which is about one-third of the per capita-water availability

in usa and japan.

the annual precipitation in the country is estimated a about 4000 cubic km.

Irrigation

Irrigation is defined as the artificial application of water on the agriculture land for the assured gowth of crops.

necessity of irrigation

• > When rainfall in the region is insufficient and unreliable.

• > When the rainfall in the region is not distributed throughout the crop period or year.

• > In arid (dry) and semi-arid regions that is, places Where cultivation is impossible without irrigation.

• > When it is necessary to grow a particular crop more than once in a year.

• > When perennial crops to be grown, which requires wawr throughout the year.

advantages of irrigation

• It helps in increasing the food production by assured and increased crop yield.

• Irrigation helps in making the country self-sufficient in food production.

• It helps to raise those crops which cannot be grown only on rainwater.

• help of irrigation, mixed cropping may be eliminated and single superior crop may be grown to get the maximum benefits.

• It is possible to grow more than one crop in a year with the help of irrigation.

• Major irrigation projects can be design for generation of power, water supply and other purposes which leads into general prosperity of a country.

• It is possible to have cheaper communication systems either in land navigation through

• irrigation canal or by using the service roads by the side of irrigation canal for transportation.

disadvantages

• Overirrigation leads to water logging and thus results in reduced crop yields.

• If the water logging unchecked in its initial stage the land gets salt effected and it is impossible to raise any crop on such land.

• Intense irrigation may results in colder and damper climate causing out break of diseases.

• Due to excessive application of water and due to leakage from canals, the pits and depressions get filled up with water. These stagnant pools of water act as breeding places for mosquitoes and the region becomes malaria prone.

• Valuable land may be submerged due to construction of reservoir by dam, weir and barrages.

• In unlined irrigation canal, excessive seepage of water through bed and sides takes place which raises the water table of the surrounding areas.

water resources project of india

water resources project of karnataka

multipourpose river vally project