Water Flashcards
Water scarcity causes
- variations in seasonal and annual precipitation
- over-exploitation, excessive use, unequal access to water
- large and growing population
> greater demand for domestic use
> produce more food : expand irrigation for dry season agriculture - industries
> users of water
> hydroelectric power (22% of total electricity produced) - urban areas societies and colonies: own groundwater pumping devices, farmers: own wells and tube wells
Need of the hour with respect to water
- conserve and manage water resources
- safeguard ourselves from health hazards
- ensure food security, continuation of livelihoods and productive activities
- prevent degradation of our natural ecosystems
Hydraulic structures in Ancient india
- 1st cent BC, Sringaverapura (near allahabad): water harvesting system channeling the flood water of the river ganga
- Chandragupta Maurya, dams lakes and irrigation systems built
- Kalinga, Nagarjunakonda, Bennur, Kolhapur
- 11th cent., Bhopal lake, one of the largest artificial lake that time
- 14th cent., tank in Hauz Khaz, Iltutmish, water to siri fort area
Dams purpose
Irrigation
Electricity generation
Water supply for domestic and industrial use
flood control
recreation
inland navigation
fish breeding
Dams examples
Satluj-Beas river basin
> Bhakra-Nangal Project
-hydel power + irrigation
Mahanadi Basin
> Hirakud project
- conservation of water + flood control
What did J Nehru say about dams and why
‘Temples of India’
integrate dev of agriculture and the village economy with
rapid industrialization and growth of urban economy
Scrutiny against dams + movements
- Affect natural flow of river, cause excessive sedimentation and make beds rockier: poorer habitats
- Fragment rivers making migration for spawning difficult
- Submerge and cause decomposition of existing vegetation and soil
- Large scale displacement of local communities, loss of livelihood and control over resources
‘Narmada Bachao Andolan’
‘Tehri Dam Andolan’
Narmado Bachao Andolan
- NGO
- mobilised tribal people, farmers, environmentalists and human rights activists
- against sardar sarovar dam, narmada river in GUJARAT
- initially focused on env issues (submerging of trees)
- now focused on enabling poor citizens esp oustees to get full rehabilitation facilities from the govt
How have dams affected agriculture society etc
- irrigation has changed cropping patterns: farmers are switching to water intensive and commercial crops
> salinisation of soil
> social gap between land owners and landless - creates conflict between people wanting different uses and benefits from the same resource
Eg: Sabarmati-basin farmers agitated, higher priority given to urban areas, esp during drought
Eg: inter state disputes with regard to sharing costs and benefits
Krishna Godavari Dispute
More water diverted to Mhrshtr at Koyna
Opposed by Karnataka and Andhra Pradesh
Negative failures of dams
- Trigger floods due to sedimentation
- Big dams unsuccessful in controlling floods during heavy rainfall
> 2006, release of water from dams during heavy rain aggravated flood in Gj and Mhrt - Extensive soil erosion
- flood plains deprived of silt, a natural fertilizer
- induce earthquakes
- cause water borne diseases
- pests and pollution due to excessive use of water
Rainwater harvesting in Ancient india
- Hilly/mountainous regions: diversion channels
Ex: guls/kuls of western himalayas for agriculture - Rj: rooftop, store drinking water
- Flood plains of bengal, inundation channels to irrigate fields
- aird/semi: agricultural fields converted into rain fed storage structures that allowed water to stand and moisten the soil
ex: Khadins of Jaisalmer, Johads of rj
Tankas
Rj, (bikaner, phalodi, barmer) all houses traditionally had underground tankas for storing drinking water
- as big as a room
- rooftop rw hvsting
- built insde main house or courtyard
- sloping roofs, pipes
- first spell of rain to clean pipes and roofs
- reliable sources of drinking water when other sources dry up
- rainwater/ palar pani is considered the purest form of natural water
- constructed adjoining underground rooms, keep the room cool
RW hvsting in present day western Rj
- has declined as plenty of water is available due to the perennial Indira Gandhi Canal
- some houses still maintain tankas due to taste of tap water
Gendathur
remote backward village in Mysuru, Karnataka
nearly 200 households have installed rw hvsting system
80% collection efficiency
