Assessment of geohazard susceptibility based on RS and GIS analysis in Jianshi County of the Three Gorges Reservoir, China

摘要

Geohazards are always followed by many disasters that threaten people's lives and property. They have a characteristic of simultaneous occurrence and regionality. In this century, researchers pay more attention to the mechanisms and assessment methods and techniques of geohazards. The aim of this study is to complete the assessment of susceptibility in Jianshi County, Three Gorges Reservoir in order to avoid disasters and reduce the losses. On basis of the field survey data, the impact factors are chosen and graded. The entropy model is employed to the compute values of different impact factors quantitatively with ArcGIS. All impact factors are weighted based on the calculation results of the entropy model. The result of assessment susceptibility is calculated by different impact factors and reclassified into very high, high, medium, and low susceptibility zones as 10, 20, 30, and 40 % of the total area of Jianshi County, respectively. The percentage is 41.34, 23.90, 21.71, and 13.05 % of the total areas of 162 geohazards and 26.70, 43.52, 23.02, and 6.76 % of the total area of 20 validated geohazards in very high, high, medium, and low susceptibility zones, respectively. There is a significant consistency between the result and validated result. According to the success rate curve, the overall success rate is about 75%. The present results are scientific and useful for the government management of the geohazards and planning for development.