Improved slope unit method for fine evaluation of regional landslide susceptibility

Abstract

Susceptibility evaluation is the basis of regional landslide risk early warning and stability analysis. Scientific and reasonable division of evaluation unit is the key to landslide susceptibility evaluation. For large-scale fine landslide susceptibility evaluation, the traditional slope unit division method based on hydrology and geomorphology generally results in low accuracy of the evaluation. In this paper, an improved slope unit method based on the slope geological environment is proposed. Dazhou Town was selected as an example and the obtained results from the proposed model were compared with the results from hydrological analysis method and curvature watershed method. The results show that the size uniformity of the evaluation units divided by the proposed method is better, and no fine units or deformed long strip units were generated. The overall morphological characteristics of the evaluation unit are more reasonable, and the morphological index is between 1 and 2, which generally presents circular-like or square-like shape. At the same time, the superposition degree between the results of the improved slope unit division and the range of the existing disaster boundary is the highest, which can better reflect the physical significance of landslide risk assessment. The proposed model has significant potential for improving the accuracy of regional landslide susceptibility evaluation.

Keywords

• regional landslide
• susceptibility evaluation
• slope unit
• division method
• arcgis