Quantifying Geotechnical Changes in the Rafsanjan Plain in Time Series and Finding Out Their Causes Using Radar Remote Sensing Techniques

Subsidence is the earth’s surface movement towards down relative to a datum such as sea level. The main reason of subsidence in Iran is groundwater overuse which if not managed correctly, it causes irreparable damages. Therefore, the first step in solving this problem is identification of subsidence areas and estimating the rate which will have a significant role in controlling this phenomenon. One of the most suitable methods of identification of subsidence is using Interferometric Synthetic Aperture Radar (InSAR)technique. This method is superior to other detection T in terms of cost, precision, extent of the study area and time and it can provide an accurate estimate of the area. In this research, zone of the Rafsanjan plain has been investigated between ۲۰۰۶ and ۲۰۱۰. In order to calculate subsidence rate, SAR data related to the ASAR sensor in C-band and ALOS PALSAR in L-band were used. Generalized linear models in C-band and L-band with values of ۰.۹۱ and ۰.۸۹ and RMSE coefficient of ۰.۳۷ and ۰.۶۱ represented a strong linear relationship. Also the relationship between subsidence and the changes inpiezometric levels (groundwater extraction) in the study area showed that for each ۴.۷ centimeters groundwater level decrease, there has been ۱ centimeter subsidence.