城市典型下垫面空间构型对降水蓄渗率的影响

采用人工模拟降雨装置,定量研究了城市典型下垫面空间构型与降水蓄渗率的关系.在保证降雨量和降雨历时不变,改变不透水斑块的重要值、形状、均匀度和分离度,测定降水产流量,并计算降水蓄渗率.结果表明,降水蓄渗率随不透水斑块重要值、形状、均匀度、分离度的改变而发生相应变化,不透水斑块的重要值对降水蓄渗率的影响最大,不透水斑块的形状、分离度和均匀度对降水蓄渗率的影响也很显著.研究证明,在城市景观中,不透水斑块重要值一定时,合理配置不透水斑块的形状、均匀度和分离度,可以有效调控城市降水蓄渗量.

Effect of Spatial Structure of Typical Urban Underlying Surface on Rainfall Infiltration Rate

The objective of the study describes the quantitative relationship of the spatial structure of urban underlying surface and rainfall infiltration rate.The rainfall simulator is designed to study the proportion,shape,evenness and separation of impervious patch influence on rainfall infiltration rate in the same initial condition.The results show that changing the proportion,shape,evenness and separation of impervious patch causes different rainfall infiltration yield.Factors of affecting rainfall infiltration rate of urban underlying surface spatial structure,proportion of impervious patch have great contribution to the rainfall infiltration rate.The effect of shape,evenness and separation of impervious patch is less than the contribution of the proportion of impervious patch.However,the effect of shape,evenness and separation of impervious patch on rainfall infiltration rate is also very prominent.In urban landscape,arrange the shape,evenness and separation of impervious patch rationally will be very effective on controlling urban rainfall infiltration yield.