关键词: 香港, 滑坡泥石流, 成因分析, 防治方法

Abstract: Physiographically, Hong Kong is a hilly terrain with thousands of steep slopes, on which are constructed numerous tall buildings and high-density residential complexes. The rapid pace of urbanization and building construction, coupled with the topographic relief, led to the occur-rence of numerous disastrous landslides during the rainy season. Landslide hazard has thus be-come the major natural hazard in the Hong Kong region. This paper reviews a number of ma-jor landslides which occurred in the past three decades, analyzing the characteristics and causative mechanism of landslides in Hong Kong. It is concluded that the landslides are trig-gered by heavy rainfall, which infiltrates the subsoil, leading to a singnificant increase in its degree of saturation and a corresponding loss in suction and shear strength of the soil. This re-duction in shear strength upon saturation and wetting is the main reason for the occurrence of landslides. Slope failures often occur during the later part of a heavy rainstorm, in decomposed granite and volcanic residual soils. Most of the landslides involve relatively shallow depths. The paper also outlines the slope stabilization measures commonly adopted in Hong Kong, in-cluding shotcreting or chunaming of slope surface to prevent infiltration of rain water, surface and subsurface drainage, anchoring, soil nailing, slope angle and/or slope height reduction, etc. By far, the most effective slope stabilization measure consists of slope surface protection coupled with drainage. It is further noted that the study of debris flows on natural slopes will be a major focal point for research in the years ahead, with particular emphasis on causative mechanisms and predictive capability.

Key words: Hong Kong, landslide, causative mechanisms, prevention and treatment method