Fatemeh Mahmoodinasab, Neda Mohseni,
Volume 8, Issue 3 (12-2021)
Abstract
Despite extensive studies on the relationship between land subsidence and groundwater level, less research were focused on the impacts of distance to pumping wells on variation of land subsidence area. This study presented the linkage between the ground surface displacement rate and groundwater pumping area and the associated geomorphic consequences. The land subsidence rate was extracted from Sentinel-1A images. Then, to evaluate the relationship between the ground surface displacement extent and distance from the pumping wells, 30 pumping wells were identified within the study area. Different buffers at specified distances (500, 700, 1,000, 1,300, 1,500, 2,000 m) were created around each well. To test the effect of the distance to the pumping wells on the spatial extent of critical and slight subsidence areas, average annual images of land subsidence were classified into two classes, including areas with a maximum subsidence rate and a minimum subsidence rate. Further, earth fissure identified by GPS were transformed to the land subsidence classification map. The results showed that there is a significant relationship between the distances to pumping wells and displacement extent. The spatial extent of areas with the maximum subsidence rates decreased as the distance from the pumping wells increased. By contrast, the spatial extent of areas occupied by the minimum subsidence rates increased with increasing the distance from the pumping wells. Also, the density distribution of the earth fissures increased in areas with the maximum subsidence rate.
