Identification of landslide hazards based on multi-source remote sensing technology:A case study of the Changli area in Hunan Province
Due to the intricate geographical and geological environment,the mountainous-hilly area of Changli in northern Hunan Province is challenged by numerous,widespread,scattered,and frequent landslide hazards,which constitute the most significant geologic hazard that causes casualties and economic losses.The multi-source remote sensing technology integrating InSAR,optical remote sensing,LiDAR,and GIS is currently a high-feasibility and high-precision landslide hazard identification and monitoring technology,meeting the requirements for macroscale and timeliness.This study identified and extracted landslide hazards in the Changli area based on InSAR deformation rate data,multispectral images,and DEM data.First,two decision tree classification methods were employed to classify the land use types based on multispectral images,facilitating the observation of land use types and their distributions in the Changli area.Then,five topographic factors,including elevation,slope,aspect,undulation,and curvature,were extracted from DEM data to evaluate the landslide risk in the Changli area.Then,five topographic factors,such as elevation,slope,aspect,undulation and curvature,are extracted from DEM data to evaluate the landslide risk in the study area.Furthermore,the time-series surface microdeformation of the Changli area was measured based on SBAS-InSAR technology.Finally,landslide hazards were extracted and delineated in the GIS by combining risk assessment results and deformation rates.Additionally,based on the classification and regression tree(CART)results and the river system distribution in the Changli area,risk inference was conducted on zones with deformation rates exceeding-0.01 m/a except the delineated landslide hazard sites.This study identified several small-scale landslide hazards with high concealment in vegetation-covered and bare zones,delineating their spatial distribution ranges,which covered an area of 0.126 km2.The multi-source remote sensing technology proved effective,demonstrating certain practical application value.
landslide hazardDEM datadecision tree classificationSBAS-InSARChangli area in Hunan
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