Participatory Modelling of Surface and Groundwater to Support Strategic Planning in the Ganga Basin in India

Abstract

The Ganga Basin in India experiences problems related to water availability, water quality and ecological degradation because of over-abstraction of surface and groundwater, the presence of various hydraulic infrastructure, discharge of untreated sewage water, and other point and non-point source pollution. The basin is experiencing rapid socio-economic development that will increase both the demand for water and pollution load. Climate change adds to the uncertainty and future variability of water availability. To support strategic planning for the Ganga Basin by the Indian Ministry of Water Resources, River Development and Ganga Rejuvenation and the governments of the concerned Indian states, a river basin model was developed that integrates hydrology, geohydrology, water resources management, water quality and ecology. The model was developed with the involvement of key basin stakeholders across central and state governments. No previous models of the Ganga Basin integrate all these aspects, and this is the first time that a participatory approach was applied for the development of a Ganga Basin model. The model was applied to assess the impact of future socio-economic and climate change scenarios and management strategies. The results suggest that the impact of socio-economic development will far exceed the impacts of climate change. To balance the use of surface and groundwater to support sustained economic growth and an ecologically healthy river, it is necessary to combine investments in wastewater treatment and reservoir capacity with interventions that reduce water demand, especially for irrigation, and that increase dry season river flow. An important option for further investigation is the greater use of alluvial aquifers for temporary water storage.

Cleaning the River Ganga: Impact of lockdown on water quality and future implications on river rejuvenation strategies

“…Major Himalayan tributaries of the Ganga are Yamuna, Ghagra, Gandak and Kosi which supply the majority of the water to the plains ( van der Vat et al, 2019 ). The river flow exhibits a marked seasonality with average monsoon season discharge 6 to 7 times higher than the average dry season discharge ( Singh and Pandey, 2019 ).…”

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“…Van der Vat et al [7] present a case study of participatory modelling for the Ganges River Basin in India, that demonstrates the integration of Earth observations with in situ data within a basin modelling framework, coupled to a customized dashboard to support collaborative interactions and to guide basin planning decisions. While building on past modelling efforts for the Ganges, van der Val et al present the first attempt to bring together analytical models for surface and groundwater hydrology, water quality, riverine ecology within an IWRM framework to explore the potential impacts of both future climate change and socio-economic development for the Ganges Basin.…”