Groundwater sustainability under land-use and land-cover changes

Abstract

In recent decades, agricultural activities have increased water withdrawals from the Shazand plain in the Markazi Province (Iran). In this study, the Soil & Water Assessment Tool (SWAT) model was used to estimate recharge content as an essential component of groundwater models. MODFLOW2000 in the GMS10.5 software was used for groundwater modeling, and the extent of land use change in the Shazand plain was investigated. The results showed that the agricultural sector allocated the largest change with an 18% increase. During 2009–2016, the water table declined by 5 m due to the decrease in recharge and the increase in exploitation. Therefore, the management scenarios of removal of irrigated crops, optimization of cultivated area, and reduction of the cultivated area by 10, 20, and 30% were applied. The results showed 3, 0.28, 0.49, 1, and 1.5 m increases in the water table at the end of the 7-year study period. Every year, reduction of the cultivated area by 10, 20, and 30%, almost 31, 20.5, and 10.3 million m3 less will be extracted from the aquifer.