Impact of Urbanization on the Hydrology of Ganga Basin (India)

Large scale emigrations from rural areas to urban areas and population growth have been uninterrupted and accelerating phenomena in parts of Ganga basin, where urbanization is increasing at an unprecedented rate.

Urban agglomeration is causing radical changes in groundwater recharge and modifying the existing mechanisms. Majority of the cities are sited on unconfined or semi confined aquifers depend upon river water and groundwater for most of their water supply and disposal of most of their liquid effluents and solid residues to the rivers and ground. There has also been an inevitable rise in waste production.

Drainage of surface water has been disrupted as the small natural channels and low lying areas have been in filled, often with municipal waste. Total water potential of the Ganga basin including surface water potential and ground water potential is around 525.02km3 and 170.00km3 respectively. Basin supports approximately 42% of the total population in India.

Water tables are declining at approximately an average of 0.20m per year in many parts of the basin and there is a trend of deteriorating groundwater quality. The demand of water has been increased many folds and most of the areas are highly reliant upon the groundwater to meet this increasing demand for water, but unfortunately degradation of groundwater both in terms of quantity and quality has deteriorated the situation.

Studies shows that change in climate may increase temperature by 2 to 6°C and can reduce precipitation up to 16%, which could reduce the groundwater recharge by 50%. In densely populated Ganga basin urban drainage consumes a high proportion of the investments into urban infrastructure and needs integrated approach for the sustainable development of water management, water education regarding conservation and pollution caused by urbanization.

Keywords:  Urbanization, Population growth, Ganga basin, Soil salinity, Water quality, Climate change, Urban infrastructure

Taxonomy

• Basin Irrigation
• Quality
• Integrated Urban Water Management
• River Studies
• Climate Change
• River Engineering
• River Restoration

1 Comment

1. An integrated smart water system is required to be developed which will include both fresh water and waste water management in urban areas within Ganga river basin.  A brief overview can be given as follows –

   - Connectedness- Using ICT as an integrator integrating and documenting data pertaining to all forms of water use within the urban area. ICT network integrated with  sustainable water network shall provide all essential information in hands and thus will help providing improved service. Now connecting this ICT with GIS will give holistic view of water resource management in urban areas.

   - Water based infrastructure - Efficient management of  water supply, sewerage, drainage and storm water management and integrating and making those an integral part of ecological networks of  cities. For  e.g. permeable pavements for run-off storage and pollutant removal through filtration and absorption. Also use of natural processes and use of landscaping for storm water treatment may also help in this regard.

   Use of smart devices, even for micro water management may result into bigger success. For e.g. installing water sensor technology in tree-pits in gardens (and eventually in street side trees) will not only helps saving water but also will alert civic authorities when trees will be in need of water.

   - Optimization of water use from all the sources of water use and matching water quality with the purpose of water use. Using proper  ICT tools shall really help in this regard.

   - Water accumulation  is another important aspect in urban areas.  Developing rainwater harvesting system in different parts of the city, especially in gardens and green areas will also help recharging groundwater. Rooftop ground water may provide important support to domestic water consumption. However, it will not be the alternative to water supply from municipal authority.

   - Planned use of waste water will turn it into productive water.  Treated waste water can be reused in urban gardening, urban forestry and industrial processes. Even nutrients in wastewater can be used in fertilization production. Also, turning wastewater into alternative energy source , like Ethanol.

   Treated wastewater can also be used in domestic areas for reusing in toilets for WC. This will significantly reduce pressure on water consumption in urban areas.

   - Water loss management and monitoring will have significant positive impact on urban water management as municipal authorities are really struggling to coping with population growth and water scarcity on urban areas.

   - While Ganga flowing through one side of the city, landscapes of other three parts of  peri-urban areas  must be dominated with waterbodies like, wetlands, ponds, lakes etc.  This will not only help in recharging ground water and support  development of natural ecology in the regions but also provide employment in the form of fisheries and aquaculture which will eventually reduce pressure on Ganga.

   - Smart water system also means engineering alternatives to design of the drainage network. Drains which receive filtered surface run off are designed with permeable edges that in‐turn help grow riparian vegetation that supports aqua flora and fauna.

   - Life Cycle Assessment (LCA) of water use, waste water treatment  etc.  will help efficient water use in urban areas.  

   All of these steps will help in reducing pressure on Ganga from water use in adjacent urban conglomerations. Next consideration shall be given to reducing waste and pollutant pressure on Ganga from urban areas.