Hydrological modelling of an agricultural watershed in India using the Soil and Water Assessment Tool.

摘要

Water availability is influencing crop yields in the Padmalaya watershed in Central Maharashtra, India, which are currently below potentially attainable yields. A number of rainwater harvesting structures such as in-stream check dams have been put in place, with the aim of improving water availability for agricultural production. The SWAT model was manually calibrated for hydrology using measured streamflow data from January to July 2010. Simulations were carried out for the period from 1977-2007 under various biophysical management conditions, with climatic data collected from the Jalgaon meteorological station. Future scenarios encompassing rainwater harvesting, climate change, land use change, and water conservation practices were evaluated. The simulation outputs were used to assess the impacts of the different factors on hydrological processes and crop yields for a 30-year period. Results show that in-stream structures significantly increase groundwater recharge. In addition, increased precipitation associated with climate change is likely to contribute to increased agricultural yields and crop water productivity. While the specific results from the simulations are limited to the Padmalaya watershed, the lessons learnt in terms of applicability of rainwater harvesting strategies in the context of climate change can be extended to similar agro-ecoregions of India..