Early identification of hidden dangers of lanslides based on the combination of ascending and descending orbits InSAR and high spatial resolution optical remote sensing: A case study of landslides in Longde County, southern Ningxia

Longde County in southern Ningxia is located at the western foot of Liupan mountain. Geological conditions is complicated. Affected by seasonal heavy rainfall, landslides and geological disasters occur frequently in the area, which poses a serious threat to local people's lives and property. In consideration of the high fractional vegetation in study area, integrated remote sensing technologies combined of Synthetic Aperture Radar Difference Interferometry technology and high spatial resolution optical remote sensing have been used in early detection of Landslides in the Longde county. Stacking technology has been used to calculate the rate of deformation from 2019.01 to 2021.05, in the direction of ascending and descending orbit. Combining high spatial resolution optical remote sensing images and digital elevation model (DEM), the interpretation key of landslide in the area deformation has been established. Then the early detection of landslides and ground survey in Longde county have been done. Through the integrated remote sensing technologies, 47 landslides were detected. 21 landslides were surveyed by field, of which 16 were verified, with an accuracy rate of 71.4%. The results of field survey demonstrated the applicability and feasibility of integrated remote sensing technology in the detection of landslides in southern Ningxia. Meanwhile, and the accuracy of the results in Longde county has been testified. The results of the early detection through integrated remote sensing technology provided significant scientific bases for the landslide protection and emergency response to sudden geological disasters in southern Ningxia.