南宁市设计暴雨空间异质性特征

Spatial heterogeneity of design rainstorm in Nanning

针对我国城市暴雨频发,空间异质性增强,内涝严重的问题,基于1998—2015年TRMM 3 h卫星降雨数据,以海绵城市试点城市——南宁市为例分析各重现期暴雨频次、空间异质性及下垫面要素的影响特征。结果表明:①南宁市实际暴雨发生频次显著高于其对应理论频次,且在城市中心与非城市化之间过渡带区域多出现暴雨中心;②研究区各重现期暴雨均具有较显著的空间总体和局部正自相关性,局部聚集类型以“高高”和“低低”为主;③研究区各重现期暴雨空间分布总体受经度和纬度的影响最大,坡向和海拔高度的影响次之,坡度的影响最小且其影响的空间格局具有空间非平稳性。研究结果可为南宁市整体海绵城市建设方案及雨洪内涝应对的顶层规划设计提供重要科学支撑。

Aiming at the problems of frequent urban rainstorms,enhanced spatial heterogeneity and severe waterlogging in China,basing the research on the rainfall data of TRMM 3h satellite from 1981 to 2015,we took Nanning,a pilot city of sponge city,as an example to analyze the influence characteristics of rainstorm frequency,spatial heterogeneity and underlying surface factors in each recurrence period.The results show that:①the actual frequency of heavy rain in Nanning is significantly higher than the corresponding theoretical frequency,and more heavy rain centers appear in the transition zone between the urban center and the non-urbanization area.②the rainstorm in each recurrence period of the study area has a significant positive autocorrelation between the spatial population and the local area,and the local aggregation types are mainly“high”and“low”.③the spatial distribution of heavy rain in the study area in each recurrence period is affected by the longitude and latitude the most,followed by the slope direction and altitude.The spatial distribution of heavy rain in the study area was least affected by the slope in the whole,and the spatial pattern affected by it was non-stationary.The research results can provide important scientific support for the overall sponge city construction scheme and the top-level planning and design of the flood and flood response in Nanning.