Improving hydro-social process representation of the hydrological model CWatM at the example of the Upper Bhima basin in India

The Community Water Model (CWatM) is an open-source hydrological model designed to assess water availability, anthropogenic and non-anthropogenic water demands, and environmental need. Here we apply CWatM to the Upper Bhima basin in India of around 50,000 km2. The basin and especially the city of Pune are already facing increasing water demands that leads to competition between urban and agricultural sectors. To assess the interaction in the basin concerning changes in land cover, climate, water use, reservoir management, irrigation water management and distribution, and groundwater management we use the hydrologic model at a daily resolution and a spatial resolution of ~1 km (30 arc second). It is coupled to the MODFLOW groundwater model at 500 m resolution, includes an improved reservoir management dedicated to irrigation together with the inclusion of the irrigation channel network. We show results on optimising groundwater pumping and reservoir management for irrigation and domestic water use under changing socio-economics and changing climate. This study is part of the Food-water-energy for Urban Sustainable Environments (FUSE) project, which looks at the interactions among food, water and energy (FWE) and requires an integrated approach that takes into account coupled human-natural system and incorporates stakeholder participation. In this project frame the improved model representation will enable us to test pathways to sustainable land use for different sectors and to develop together with the stakeholders potential policy interventions that improve the sustainability of FWE resources.