Landslide assessment using radar images and radar interferometryCase area: Nirchai Basin

Radar interference technique is an efficient method in measuring ground surface displacement. So that with the use of this technology, it is possible to monitor small movements of the earth's surface continuously, with high accuracy and in a wide range. This technology has become very common in the study of natural disasters of the earth, including slope displacement, subsidence, earthquakes and volcanic activity. This technique compares the phase taken from two radar datasets at two different times and, by creating an interrogram, is able to measure changes in the earth's surface over time. In this study, in order to identify and measure landslides, radar images of 2015 and 2021 were used. In order to process the information, SARSCAPE software has been used, which has an estimated maximum landslide of 34 cm. Land use map of the study area was extracted using Landsat 8 image and using object-oriented classification. The results of this study showed that radar images have a good potential for detecting the instability of slopes and calculating their displacement. The results of adapting the land use map to the landslide map showed that the highest amount of slope movements are in the vegetation uses with 33 cm and the range with 28 cm, respectively, with the lowest value to the residential area with 9 cm. Sudden landslides and the destruction of vulnerable structures are possible accidents resulting from the effects of sloping movements that cause human casualties in urban areas. In some cases, these accidents can cause heavy and irreparable losses due to high population density or the expansion of the radius of the collapsed lands.