Investigation of subsidence phenomenon and impact of groundwater level drop on alluvial aquifer, case study: Damaneh-Daran plain in west of Isfahan province, Iran

Abstract

The subsidence phenomenon is influenced by several factors, the most important of which is the overutilization of alluvial aquifers or reduced aquifer recharge as a result of climate change and drought. Alluvial Damaneh-Daran aquifer in central Iran is an unconfined aquifer. But due to its lithological diversity, behave similarly to a confined aquifer. Therefore, the aquifer is susceptible to subsidence. The subsidence in the study area was investigated using a hybrid numerical approach. Therefore, the rate of subsidence in the aquifer was first determined by the radar interferometer method. Then, to investigate the effecting parameters on subsidence, a groundwater model was constructed that showed a negative water budget. The fifty percent exploitation decrease scenario from the aquifer showed the significant and considerable effect of reducing pumping on the decrease in subsidence. Therefore, it was concluded that one of the primary and compelling reasons for the subsidence event in the Damaneh-Daran alluvial aquifer was the overexploitation of the aquifer. Given the lack of suitable and portable water resources in the catchment, changing the pattern of cultivation and optimal utilization of groundwater resources is a management strategy to control the current trend of overuse of aquifer and subsidence events.