Investigating the effect of groundwater loss on land subsidence, a case study: Chenaran city

The phenomenon of land subsidence is one of the dangers that has occurred in many areas of the plains of our country in recent years and has led to many problems. Identifying areas subject to land subsidence and estimating its rate has an important role in managing and controlling this phenomenon. The radar interferometry technique is a powerful tool in estimation and has the amount of ground subsidence with an accuracy in the millimeter range using phase observations. In this research, the data of Sentinel 1A satellite from 2017 to 2021 have been used in order to monitor the subsidence that happened in Chenaran city by sensor-radar interference method. To investigate the subsidence of Chenaran city, radar interferometric method, Sentinel 1 satellite images and available information of piezometric wells in the area were used and the piezometric changes of the water level of the wells were analyzed. According to the results of the current research, the amount of land subsidence for each period is 9 cm for 2017-2018, 10 cm for 2018-2019, 10 cm for 2020-2019, and 13 cm for 2020-2021. be Also, the results of the radar interferometric technique showed that during the statistical period, 42 cm of subsidence occurred in the studied area. In addition, the areas with severe land subsidence, especially in the areas of Seyed Abad, Akhlamed, Haji Abad, Chahcheh, Hashem Abad, Kalate Sheikha, etc., corresponded to the areas with the highest level of underground water level drop. In general, the most important and main cause of land subsidence in the studied area is the excessive extraction of underground water resources, which has caused the dangers of land subsidence.