Conjunctive Use Modeling Using SWAT and GMS for Sustainable Irrigation in Khatav, India

Abstract

AbstractThe present study engages two powerful models viz., Soil and Water Assessment Tool (SWAT) and Groundwater Modeling System (GMS) to simulate groundwater and surface water conditions to aid conjunctive use applications. This work elaborates a robust coupling of these two models for conjunctive use studies. The study area, Khatav in Maharashtra, is mostly drought-prone, semi-arid and has an average annual rainfall of about 560 mm. In order to have a sustainable and efficient water resource management in this semi-arid region, conjunctive use of groundwater and surface water is essential. Therefore, the SWAT and GMS models were calibrated and validated by using observed data for a period of twelve years, from 2000 to 2012. The basin area considered for the study purpose is 470 km2. After the SWAT model has been processed, study area was divided into 51 hydrological response units (HRUs) and 5 sub-basins. The methodology used in this work was, the Soil Conservation Service (SCS) curve number was used to estimate surface runoff. As the SWAT model cannot be used to predict groundwater levels in the basin, the Groundwater Modeling System (GMS) has been used to model the groundwater processes. The sensitivity of work was assessed by using SWAT-CUP tool and with SUFI-2 algorithm. The results showed that the average annual flow from the basin is 3.059 × 103 m3 and average curve number is 87.43. The study recommends recharging of the wells which are already available in the basin by operating them continuously to induce recharging by available surface water. The simulation shows that altogether due to reduction in evaporation and surface absorption, the groundwater level in basin is raised by 0.6 m. The validity of the simulations and acceptance of the SWAT model for the present study has been confirmed by values of RSR (0.60) and NSE (0.82) parameters.KeywordsSurface waterGroundwaterConjunctive useSWATGMS