Abstract
Steep natural terrain in Hong Kong, combined with deep weathering profile and high seasonal rainfall, is highly susceptible to rain-induced, shallow landslides. With over 35 years of practice in landslide risk management, Hong Kong has progressively built up a series of important databases that facilitate conducting state-of-the-art research and development works on landslides. Amongst others, there is a dense network of raingauges that provides state-of-the-art rainfall records, a high-resolution inventory of historical landslides and a LIDAR-based digital terrain model for natural terrain. This paper will firstly discuss the previous landslide susceptibility map for natural terrain in Hong Kong, and then present a new territory-wide rainfall-based landslide susceptibility analysis for natural terrain that takes cognizance of effect of slope angle. The year-based susceptibility model correlates landslide density with normalized maximum rolling 24-hour rainfall for eight different slope angle classes. The potential applications of the outcomes of the landslide susceptibility analysis will also be discussed.
