Study Of Geo-Hazards Investigation For Baihetan Reservoir Bank By InSAR Technology

Baihetan hydropower station,the second largest hydropower all over the world,is located in the downstream of Jinshajiang River.The hinterland of southwest China has strong tectonic activities with Xiaojing active fault getting through aand Jinshajaing River valley is extremely steep.The elevation of valley varies hugely and the rock erosion is severe.Besides that,there are lots of old landslides here,the problem of geological hazard has been increasingly serious.Foreseeably,the situstion of new landslides generation and old landslides alive will get worse after Baihetan hydropower station reservoir storaging.It is significant for migration,geologicial hazards control and study on varies of geologicial hazards before and after storaging to investigate information of slope deformation and distribution of geologicial hazards in reservoir bank.InSAR technology can work in any time and any climates,it also has an advantage on large-scale measurement and precise result.Combined Optical remote sensing technology with practical investigation of Qiaojia-Luji area,there is a preliminary conclusion about type and distribution of geologicial hazards in Baihetan hydropower station reservoir bank.By analyzing typical slow-moving landslides of InSAR measurement,the following recognizations can be listed:(1)Geologicial hazards recognization by optical remote sensing and pratical investigation of Qiaojia-Luji area indicate that landslide is major geologicial hazards in Baihetan hydropower station reservoir bank,including dangerous slops and rock deformations,and most of landslides are large-scale in size.Most of rockfall hazards are small-scale in size,which usually destroy road.The number of debries flow hazards is small and most of them have low activities;(2)The study area is monitored in multiple angle,multiple dimension and multiple series by using PALSAR-1(L band)and Sentinel-1(C band)data.It is proved that effective monitoring area can be increased to 95%by using ascend and descend SAR data at the same time.Repetitive measurement area is less than 10%between ascend and descend monitoring.(3)D-InSAR,Stacking-InSAR and IPTA-InSAR technologies have a good effect on geologicial hazards recognization by working together.The result of distinguishing dangerous region of landslides by InSAR is consistent with pratical investigation,and it is proved that InSAR technology can be applied in distinguishing dangerous region and valuing macroscopic stability of geological hazards correctly and conveniently.The component of landslide can be divided and its movement can be analyzed by using InSAR technology.IPTA-InSAR method can acquire highly precise deformation rate historical deformation curve of target,it is proved that InSAR technology has an advantage and potentiality on geological hazards monitoring.