岩溶区德保县极端降雨事件时空演变趋势分析

岩溶地区暴雨内涝成因复杂,其中直接外因是连续高强度降雨,内涝受灾损失严重,因此迫切需要系统地分析岩溶地区的极端暴雨演变规律。广西区德保县是一个典型的岩溶地区,遭受过几次重大内涝灾害,利用该县7个雨量站1983~2013年逐时及逐日降雨资料,采用线性倾向估计法、累积距平曲线法、MannKendall法和ArcGIS技术,研究了德保县极端暴雨事件的时空演变规律。结果表明,近30年来德保县集中度高的短历时暴雨强度增加,该县西北部的短历时暴雨较强,极端降雨事件的突变年份在1998、2011年附近,应加强该地区的防洪排涝设施建设。

Temporal and Spatial Evolution Law Analysis of Extreme Rainfall Events of Karst Area in Debao County

The cause of water logging in Karst area is complex. The most direct cause is continuous high intensity rainfall which causes serious losses, and there is an urgent need to analyze the evolution law of extreme rainstorm events in Karst area. Debao County in Guangxi Zhuang Autonomous Region is a typical Karst area, which suffered several major disasters. In order to understand the cause of water logging, based on the hourly and daily rainfall data of seven stations in Debao County during 1983 to 2013, the spatial and temporal evolution law of extreme rainfall events was analyzed using the methods of linear trend estimation, cumulative anomaly curve, Mann-Kendall test and the technology of ArcGIS. The results show that the intensity of short duration rainstorm with high concentration increases, and short duration rainfall in the northwest of Debao County is strong. Extreme rainfall events appeared a sudden change around 1998 and 2011. We should pay attention to the flood control and drainage measures in the area.