Integrated Salt and Water Balance Modeling for the Management of Waterlogging and Salinization. I: Validation of SAHYSMOD

Abstract

Irrigated agriculture faces serious threats of waterlogging and soil salinization in the arid and semiarid regions of the world. In this paper, an integrated spatial-agro-hydro-salinity model (SAHYSMOD) was used to analyze water and salt balances of an irrigated semiarid area located in the Haryana State of India where the groundwater level is rising continuously. The calibration, validation, error analysis, and sensitivity analysis of the model parameters were performed. The sensitivity analysis revealed that hydraulic conductivity is the most sensitive model parameter for both groundwater levels and salinities, followed by effective porosity of the aquifer. The leaching efficiency of the soil is sensitive only to the groundwater salinities. The results show a good agreement between the simulated and observed groundwater levels and salinities for almost all the nodes during the calibration and validation periods. The results are also substantiated by the high R-squared values and low mean error (ME) and root mean square error (RMSE) values. On the basis of the results, it could be concluded that the SAHYSMOD performed very well in predicting groundwater levels and salinities during the calibration and validation periods.