Evaluating the effect of land-use change coupled with climate change: A study based on Sal river flow in Goa, India

Abstract

There is a constant conflict for water amongst various sectors. This is further aggravated by climate change. It is crucial to establish interaction between land-use combined with climate change and local hydrology to devise sustainable management strategies. This study used the Norwegian Earth System Model (NorESM) climate model, Land Change Modeler (LCM) and Soil and Water Assessment Tool (SWAT) hydrological model. This ensemble of models was used to predict Sal River flow in Goa, India under two Representative Concentration Pathway (RCP 4.5 and 8.5) climate scenarios. The statistically tested results indicate that the future rainfall and temperature is likely to increase and more pronounced under RCP 4.5 scenario. However, climate combined with land-use change reveals that the streamflow is likely to increase with increase in the urban/concrete areas and decline with reduction in the forest areas. For Sal River watershed, the forest cover is likely to decrease by 5.93 percent up to 2040s, with a corresponding increase in the urban/settlement areas. With the increase in the built-up areas, the surface runoff may increase and lead to an urban flooding-like situation. Dependable flows for this watershed were computed to comprehend future water availability. Site-specific recommendations have been formulated to aid the decisionmakers to implement the timely adaptation measures.