ارزیابی و پهنه‌بندی خطر فرونشست زمین با استفاده از روش تداخل‌سنجی راداری روزنه مصنوعی با پراکنده‌سازهای ماندگار (PSInSAR) در حوزه‌های آبریز استان اصفهان

This study uses artificial aperture radar interferometry using permanent scatterers (PSInSAR) to accurately measure and monitor land subsidence in a number of the most important watersheds in Isfahan province, including Isfahan-Borkhar, Najafabad, North Mehyar, South Mehyar and Kohpayeh-Segzi which are in It covers the major area of the province. The PSInSAR method is efficient in detecting very small displacements on the order of millimeters by focusing on radar-stable reflective structures known as persistent scatterers. This research has identified and measured the deformation of the earth in a period of time from 1393 to 1402, by using Sentinel-1 ascending and descending satellite images and the PSInSAR technique. The results of the research show a significant cumulative subsidence in the studied area, so that the maximum subsidence, especially in the catchment areas of Isfahan-Borkhar and South Mahyar, reaches 55 cm during the period of 2013 to 2014. The annual subsidence rate also reaches a maximum of 60 mm per year in these areas. Land subsidence hazard zonation maps have identified areas with high and very high risk of subsidence, which are mainly located in Isfahan-Borkhar and South Mahyar watersheds, while other watersheds have moderate to low hazard levels. The results show significant land subsidence in areas that correspond to the extent of urban areas, agricultural lands and pastures, and the ranges of clay layers. Integrating ascending and descending data and using the PSInSAR technique increases the accuracy of the prepared subsidence maps and is more compatible with ground observations.