Landslide hazard and risk assessment: The Malaysian experience

Abstract

Each year, landslides around the world create huge economic loss and disruption, and often result in loss of life. Landslides can occur almost anywhere, from man-made slopes to natural and pristine ground. Social and economic loss due to landsliding can be reduced by means of effective management and planning. This involves landslide hazard and risk assessment and mapping, mitigation measures, and warning systems. For the past few decades, there have been a number of methodologies developed for a better understanding of landslide hazard and risk. Hazard and risk assessment have become an important tool in addressing uncertainty inherent in mass movement. In Malaysia, due to its rapid development since the 1980s, suitable low-lying areas for development have become increasingly unavailable. As a result, development of highland or hilly terrain has increased, particularly in areas proximal to densely populated cities. Development of slope assessment systems in Malaysia to predict the likelihood of landslide occurrence began in the early 1990s. Various parties, including government agencies and private organizations, are involved in an effort to reduce landslide hazards and their consequences. Slope assessment projects carried out in Malaysia can be divided into two categories by the scale of assessment: large-scale or medium- to small-scale. Large-scale assessments are widely used in prioritizing slope maintenance along roads and highways while medium- to small-scale assessments are a tool for controling development in hilly areas. Large-scale assessments are mostly carried out by the Public Works Department (PWD), the main technical department in Malaysia, whereas the medium- to small-scale assessments are carried out by the Department of Mineral and Geosciences (DMG) and the Centre of Remote Sensing (MACRES). This paper will present experiences of various parties in Malaysia in the use of landslide hazard and risk assessment.