2001~2016年香港滑坡与降雨的时序特征

Temporal Characteristics of Landslides and Rainfall in Hong Kong,China from 2001 to 2016

随着城市建设步伐加快,城市滑坡灾害对群众生命财产安全的威胁日益突出。降雨造成的滑坡占滑坡总数的90%以上,研究降雨量与滑坡数之间的关系,对城市安全和防灾减灾具有重要意义。根据香港土木工程拓展署发布的滑坡年报中2001~2016年日滑坡时间数据、增强自然地形滑坡清单的滑坡空间数据以及香港天文台日降雨观测数据,分析香港滑坡数和降雨量之间的定量和定性关系。结果表明:日滑坡数、月滑坡数和年滑坡数,与日降雨量、月降雨量和年降雨量成显著正相关关系,其相关系数分别为0.406、0.718、0.682;当日滑坡数除受当日降雨量的影响以外,也受前13 d累积降雨量的影响;当日与前4 d累积降雨量对当日滑坡数影响明显,当日与前1 d降雨量影响权重最大,当日降雨量的权重影响平均是前1 d降雨量影响权重的1.2倍;在降雨量超过200 mm(特大暴雨)的条件下,发生群发性滑坡概率为87.5%;降雨及滑坡最集中的月份是6月,6月至8月降雨集中,滑坡灾害较其他月份更为严重。本研究对粤港澳大湾区防灾减灾和市政建设规划具有参考价值。

With the acceleration of urban construction,the impact of urban landslide disasters on the safety and property of residents has become increasingly prominent.Statistics show that landslides caused by rainfall account for more than 90%of the total landslides.The research on the qualitative and quantitative relationships between rainfall and landslide is of great significance to urban safety and urban disaster prevention and mitigation.Based on daily landslides data from 2001 to 2016 in the annual landslide report published by the Civil Engineering and Development Department of Hong Kong,the spatial landslides data from the Enhanced Natural Terrain Landslide Inventory and the daily rainfall observation data from Hong Kong Observatory,the quantitative and qualitative relationships between landslides and rainfall in Hong Kong were analyzed.The results show that the daily,monthly and annual landslides are significantly correlated with daily,monthly and annual rainfall,and the correlation coefficients are 0.406,0.715 and 0.640,respectively;the occurrence of daily landslide is not only affected by the rainfall of the same day,but also by the accumulated rainfall of the previous 13 days;the daily landslides is significantly influenced by the rainfall on the same day and the previous four days;the rainfall on the same day and the previous one day has the greatest impact on the daily landslide;on average,the impact of the rainfall on the current day is 1.2 times the impact of rainfall of the day before;when the daily rainfall exceeds 200 mm(extremely heavy rain),the probability of mass landslides reaches 87.5%;the month with the highest probability of rainfall and landslide in Hong Kong is June,and landslide disasters are more serious from June to August than those in other months in Hong Kong.This research can provide valuable references for disaster prevention and mitigation,and municipal construction planning in Guangdong-Hong Kong-Macao Greater Bay Area.