Investigating the height changes of the land surface using the SBAS radar interferometry technique in a part of Sarab county

Land displacement is known as one of the most obvious invisible effects of natural earthquake hazards. In the present study, the radar interferometric technique (SBAS) using the images of Sentinel 1 (2018 to 2021) was used to estimate the land subsidence, and the Landsat 8 image of 2018 was used to extract the land use classes in a part of the Sarab county. Also, the data obtained from the regional water organization has been used to investigate the condition of underground water in connection with the subsidence caused by displacement. According to the findings and survey of the land use map of the study area, the subsidence can be seen in different places and it reaches 9 cm per year around the agricultural areas and pastures. Also, in some places, the rising rate is estimated up to 12 cm. Examining the condition of aquifers shows a drop in the level of underground water in most stations, especially a sudden drop since the beginning of 2018. Considering that the direct relationship between groundwater withdrawal and subsidence has been fully proven; But after the 5.9 magnitude earthquake in November 2018, sudden changes have occurred in the subsidence of the region. Therefore, it seems that the subsidence of the region is more affected by the earthquake.