Frequency-volume relation and prediction of rainfall-induced landslides

Rainfall-induced landslides constitute a major public concern in Hong Kong. This paper investigates two aspects of critical importance to landslide ha zard and risk assessment and management: magnitude-cumulative frequency rel ationship for landslides, and relationship between rainfall and the occurre nce of landslides. The results indicated that landslides with a failure vol ume of not less than 4 m(3) have a cumulative frequency-size distribution w ith a power-law dependence on volume of failure. Analysis of rainfall/lands lides showed that the 12-hour rolling rainfall is most important in predict ing the number of landslides. Failure volume dependency in the relationship s between rainfall and the number of landslides is also presented. However. with an increase in failure volume of landslides, the most important rainf all variable may vary from rainfall of short duration (12-h rolling rainfal l) to that of relatively long duration (74-h rolling rainfall). (C) 2001 El sevier Science B.V. All rights reserved.