Landslides on natural terrain: Physical characteristics and susceptibility mapping in Hong Kong

Steep terrain and high frequency of tropical rainstorms make landslide occurrence on natural terrain a common phenomenon in Hong Kong. The present article reports on the use of a geographical information system (GIS) database, compiled primarily from existing digital maps and aerial photographs, to describe the physical characteristics of landslides and the statistical correlations between landslide frequency and terrain variables on Lantau Island in Hong Kong. This database is then used to obtain a logistic multiple regression model to predict landslide susceptibility. Slope gradient, lithology, elevation, slope aspect, and land use cover are indicated as statistically significant in predicting landslide susceptibility, whereas slope morphology and proximity to drainage line are not important and are thus excluded from the model. This model is then imported back into the GIS to produce a map of predicted landslide susceptibility. This study demonstrates that landslide susceptibility can be effectively modeled by using GIS technology and logistic multiple regression analysis.