Indian Water Resources – An Overview

Embassy of India, Berlin1

Indian Water Resources –An Overview

Dr. K.V. Devi Prasad

Embassy of India,

Berlin

Embassy of India, Berlin2

India -factsIndia -facts

Has many types of ecosystems – from deserts to tropical evergreen to alpine ecosystems

Total area >3.3M sq. km.

Population >1.1 billion

Population is young and growing

Demand for food and water increasing

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India Projected growthIndia Projected growth

Economy expected grow rapidly

More than 7% p.a. in the last decade and a half

Population expected to grow to ~1.6 billion by 2050.

roughly 50% increase

Per capita growth rates are high

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India – water resources at a glanceIndia – water resources at a glance

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Indian MonsoonIndian Monsoon

The largest weather phenomenon in the world

Creates a distinct “rainy season”

The rainfall is asymmetrically distributed

Creates periods of excess and periods of shortage in water availability

Even the rainiest place on earth can have water shortage for a short period!!

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Rainfall in India from Rakesh Kumar, singh &Sharma 2005

Rainfall in India from Rakesh Kumar, singh &Sharma 2005

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Water – what the future holds!Water – what the future holds!

Gross per capita water availability will decline from ~ 1820 m3 /yr in 2001 to ~ 1140 m3 /yr in 2050.

It was more than 5000 m3/yr in 1950!!

Total water requirement of the country for various activities around the year 2050 ~ 1450 k m3 /yr.

current estimate of utilizable water resource potential (1122 km3/yr)

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The decline in water availabilityThe decline in water availability

From Mall et al. 2006.

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India – the land of RiversIndia – the land of Rivers

Rivers are the basis of everything

Rivers do not “drain” their catchments ; but they irrigate their deltas!!

Most food production depends on river water irrigation – especially peninsular India

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Major River Basins of IndiaMajor River Basins of India

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Anticipated water requirements sectorwiseAnticipated water requirements sectorwise

[from Gupta & Deshpande, 2005]

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Water Availability in Indian river BasinsWater Availability in Indian river Basins

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What can be done?What can be done?

Problem is complex and there can be no simple solution

Agriculture would still be the largest demand segment

Changes in Agriculture practice may help

Conventional rice farming requires ~1m per hectare per crop; Alternate wet & dry methods can save around 30%; SRI methods can save upto 50%

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The way forward ….The way forward ….

Conservation and reuse of waste water

Most of non-agricultural use degrades the quality of water

Poses the double problems of waste and pollution

Conservation is key success

Another area would be augmenting sources

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Ground water rechargeGround water recharge

Rain water harvesting and ground water recharge are now recognised as important

Mandatory in some urban areas

3 year deficient rainfall in Chennai in 2001,02 and 03 caused major problems

But it has downside

Water flow and sediment transport is important to oceans as well!!

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Large dams??!!Large dams??!!

Would dams impounding water help/

Many criticisms of this approach

Interference to hydrogeology

Loss of biodiversity

Catastrophic failure

Sediment transport issues

Some deltas of the world are sinking!!

Rising seas and sinking deltas => human misery

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Can we engineer on large scaleCan we engineer on large scale

Some river basins have some water to spare

Can we transport water across the basins?

Costs?

Environmental consequences?

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From Mishra et al. 2007

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