WATER RESOURCES LESSON:6
INTRODUCTION
Water scarcity will pose the greatest challenge in future
Water, a cyclic resource covers 71% of the earth’s surface but only 3% is fresh water
The contested issues of the present day world are the tensions &
disputes on sharing & control of the scarce resource
Assessment, efficient use & conservation of water are necessary to ensure development
WATER RESOURCES OF INDIA
India accounts 2.45% of the world’s surface area, 4% of the world’s
water resources & 16% of the world population
Total water from precipitation in the country in a year is 4,000 cubic km
Availability from surface water & replenishable groundwater is 1869 cubic km
Utilisable water resource in India is 1,122 cubic km
Precipitation is high during monsoon season
SURFACE WATER RESOURCES
Sources of surface water are rivers, lakes, ponds
The mean annual flow in all the river basins in India is 1,869 cubic km
Due to topographical, hydrological and other constraints, only
about 690 cubic km of the available surface water can be utilized
Water flow in a river depends on size of its catchment area or river
basin and rainfall within its catchment area
GROUND WATER RESOURCES
The total replenishable groundwater resources in the country are 432 cubic km
Level of groundwater utilization is high in river basins of N-W region
Ganga, Brahmaputra basins have high replenishable groundwater resources
Ground water utilisation is very high in Punjab, Haryana & Rajasthan
Kerala, Chhattisgarh utilize small proportion of ground water
Gujrat , UP , Maharashtra, have moderate rate of utilization
TABLE 6.1 (Deleted from 2020-21 edition but mcqs can be asked )
Highest total replenishable utilization: Ganga
Lowest replenishable utilization: Subaranrekha
Highest level of groundwater: Indus
Lowest level of groundwater: Brahmaputra
LAGOONS & BACKWATERS
Lagoons: Shallow area of salt water completely or partly separated
from open sea by some obstacle like sand bank
Backwater: Part of a river in which there is little or no current
Lagoons & Backwaters are formed due to large coastline &
indented coast
These are used for fishing & irrigating crops like rice
Found in Kerala & West Bengal
WATER DEMAND & UTILISATION
India has traditionally an agrarian economy
Two third of population is dependent on agriculture
Development of irrigation has been assigned a high priority in FYP
India’s water demand is presently dominated by irrigational needs
Multipurpose projects :
▪ Bhakra Nangal- Sutlej-Himachal Pradesh
▪ Hirakud- Mahanadi- Odisha
▪ Damodar Valley-Damodar-West Bengal
PIE CHARTS
Agriculture sector uses groundwater & surface water the highest
In future with development the share of domestic & industrial sectors
of country are likely to increase
DEMAND OF WATER FOR IRRGATION
In Agriculture water is mainly used for irrigation
Needed due to spatio-temporal variability in rainfall in the country
Large parts of country are water deficient & are drought prone
Winters & Summers are dry in most parts
Irrigation should be ensured to practice agriculture
Water needs of certain crops are not fulfilled by monsoon alone ,
they need irrigation as well like rice & jute
ADVANTAGES OF IRRIGATION
It makes multi cropping possible
Irrigated lands have higher productivity
HYV crops requires regular moisture
Made Green Revolution successful
- More than 85% of the net sown area is under irrigation in Punjab, Haryana , West UP
- Wheat & Rice are two crops grown mainly by irrigation in Punjab & Haryana
- Of the Total net irrigated area 76.1% in Punjab & 51.3% are irrigated through Wells & Tubewells which shows that these state utilize large proportion of groundwater
- Overuse of groundwater has led to decline in groundwater table
- Intensive irrigation has resulted in the increase in salinity in soil also led to depletion of groundwater table
- Highest net irrigated area irrigated by Tubewells & Wells- Gujrat
EMERGING WATER PROBLEMS
Per capita availability of water is dwindling day by day due to
increase in population
Available water resources are getting polluted with industrial ,agricultural & domestic effluents
Availablity of usable water is shrinking
DETERIORATION OF WATER QUALITY
It refers to purity of water , without unwanted substances
Pollute ground water & affect aquatic life as well
Ganga & Yamuna are two highly polluted rivers in the country
WATER CONSERVATION & MANAGEMENT
Availability of fresh water is declining & its demand is increasing
Need to conserve & effectively manage water for sustainable development
We cant avail water from sea/ocean due to high cost of
desalinization
Water Saving Methods & Technologies need to be made for
conservation
Rain water harvesting & watershed development should be
encouraged
PREVENTION OF WATER POLLUTION
CPCB with SPCB monitors water quality of national aquatic resources
Public awareness & action can be very effective in reducing pollutants from agriculture , domestic & industrial activities
Legislative measures like Water Act 1974 , Water Cess Act (1977) & Environment Protection Act 1986 should be implemented effectively
Watershed development , water recycling & reuse should be encouraged
Govt. has also launched programmes like Namami Gange to curb water pollution
Methods of rainwater harvesting: Through recharge wells, service
wells, watershed management & lakes
WATERSHED DEVELOPMENT
Refers to efficient management & conservation of surface & ground water resources
Involves prevention of runoff & storage of ground water through recharge wells
Aims to bring balance between natural resources & society
Success of watershed development depends upon community
participation
In broad sense it includes conservation, regeneration & judicious use
of all natural & human resources within a watershed
WATERSHED DEVP. PROGRAMMES
- Haryali
▪ Sponsored by Central Govt.
▪ Aims to enable rural population to conserve water for drinking , irrigation
etc. - Neeru Meeru
▪ Initiated in Andhra Pradesh
▪ Water harvesting - Arvary Pani Sansad
▪ Initiated in Rajasthan
▪ Water harvesting
- Tamil Nadu has made water harvesting structures in the houses compulsory
METHODS TO IMPROVE FRESHWATER AVAILABILITY
By recycle & reuse
Water of lesser quality can be used for cooling in industries &
firefighting
Water after bathing can be used for gardening
Such measures would conserve better quality of water for drinking
use thus improving freshwater availability
RAINWATER HARVESTING
It is a method to capture & store rainwater for various uses
It is also used to recharge groundwater aquifers
Low cost & effective technique of water conservation
Increases water availability & quality
Traditionally done in rural areas using lakes, ponds, irrigation tanks
INDIA’S NATIONAL WATER POLICY
Launched in 2002, specifies water allocation priorities as:
- Drinking water
- Irrigation
- Hydro-power
- Navigation
- Industrial & other
Irrigation & Multi purpose projects should include drinking water component where there is no alternative water source
Drinking water to animals & humans is first priority
Exploitation of groundwater be limited & regulated
Surface & Groundwater to be monitored regularly
Conservation & awareness of water as a scarce resource should be spreas through education , regulation & incentives
JAL KRANTI ABHIYAN
Water availability is limited & climate change will create water stress conditions in many regions
Launched : 2015
Jal Kranti Abhiyan aim to ensure water security through per capita availability of water in the country
Aims to involve local bodies ,NGOs & citizens to create awareness
- Selection of one water stressed village in each 672 districts of the country to create a Jal Gram
- Identification of model Command Area of 1000 hectares in different parts
- Abatement of pollution- water conservation, reducing ground water pollution & construction of Arsenic free wells
- Creating mass awareness through social media , print media, etc.
- It is deisgned to provide livelihood & food security through water security