Managing landslide risk systematically using engineering works

The dense urban development on a hilly terrain, together with intense seasonal rainfall, gives rise to acute slope safety problems in Hong Kong. This is reflected by a death toll of over 470 fatalities due to landslides since the 1940s. Site formation works form an integral part of infrastructure and building development in a steeply sloping terrain. In the mid-1970s, the Hong Kong government embarked on a slope retrofitting programme, known as the landslip preventive measures programme, systematically to reduce landslide risk by upgrading substandard man-made slopes to modern safety standards. By 2010, some 4500 high-risk government man-made slopes had been upgraded through the implementation of engineering works. In 2010, the government launched the landslip prevention and mitigation programme to dovetail with the completion of the previous programme. The new rolling programme aims to contain the overall landslide risk to an ‘as low as reasonably practicable’ level by upgrading the remaining substandard man-made slopes and systematically mitigating the landslide risk posed by vulnerable natural terrain catchments. In this paper, the advances and innovations arising from this unique systematic slope safety programme are described.