香港暴雨中心迁移与滑坡位置关系分析

香港地区每年均有一定数量的滑坡灾害发生,诱发滑坡灾害的主要因子是强降水,即暴雨.暴雨过程中,降水强度的时空分布存在一定差异性,这种降水强度的时空与滑坡灾害的时空分布存在一定的联系.以香港地区1992年5月8日暴雨为例,以30 min为时间间隔,分析了暴雨中心时空变动与滑坡事件时空分布及出现频率之间的关系,发现空间上滑坡均出现在暴雨中心或暴雨中心的边沿地区;时间上滑坡事件出现在暴雨中心出现或上一阶段时间内;并且降水的强度与滑坡的出现频率也有一定关系.

Spatial and Temporal Relationship Between Rainstorm Center and Landslide Occurrence in Hong Kong

Triggered mainly by intensive rainfall or rainstorms during rainy season, tens or hundreds of landslides occur each year in Hong Kong. During one rainstorm, however, rainfall intensity is riot equal though out the storm covered area. The rainstorm center where the rainfall intensity is heaviest varies spatially and temporally during the process of one rainstorm. To analyze the relationship between landslide distribution and rainstorm center and its variation, the rainstorm occurred on May. 8, 1992 was selected as an example. Aided by geographical information system, it calculated spatial distribution of the rainstorm centers at 30 minutes temporal interval. The distribution and other characteristics of landslide occurred during the rainstorm can be extracted from landslide database supplied by Geotechnical Engineering Office of Hong Kong. The landslide distribution and other features and rainstorm center for each 30 minutes can be presented at one geographical map. Based on those relationship maps, some conclusions were given as . landslides always distribute just at rainstorm center or at the marginal area of rainstorm center, temporally, landslides occur during the same 30 minutes interval or the coming 30 minutes one. The occurrence frequency of landslide is also connected with rainfall intensity that usually the more intensive rainfall, the high possibility of landslide occurrence.