Exploring the rate and potential risk of land subsidence induced by groundwater overexploitation in a multilayer aquifer

چکیده مقاله

This research aims to explore the rate and potential of subsidence while comprehending its relationship with the over-extraction of groundwater. An innovative approach integrating three techniques: InSAR, AHP-Fuzzy, and hydrogeological analysis, enabling the crossvalidation to enhance the reliability of the findings was developed and applied on a multilayer Kuhpayeh–Segzi aquifer, in Iran. Various parameters such as long-term groundwater level, piezometric drawdown, recharge rate, distance from the fault, land use type, aquifer saturated thickness, hydraulic conductivity, and clay layer thickness of unconfined and confined aquifers, along with data from 54 Envisat images spanning from 2003 to 2010 and 97 satellite images from 2014 to 2022 are being considered to achieve the goal. Required data sourced from the Water Authority Regional of Isfahan Province, Google Earth, satellite images, and insights from 20 experts. The results showed that the groundwater level in the western, northern, and southern parts of the unconfined aquifer decreased by 11.5, 7.5, and 8.5 m over 19 years, respectively, and the significant piezometric level decline appeared in the central-western part of the plain with a maximum value of 32 m. The study identified subsidence-prone regions with an index ranging from 0.08 to 0.65, with the highest values assigned to the eastern and western. As a result of the InSAR technique, the subsidence rate was estimated to be up to 27 and 39 in each period, respectively. The findings highlight that the significant subsidence is a result of groundwater over-extraction, prompting the need for strategic interventions