简单屋顶绿化的滞蓄特性

Rainwater retention features of extensive green roof

设计了模拟降雨与数据采集系统,研究了短时强降雨下简单屋顶绿化基质(配比:陶粒57.0%、草炭41.5%、保水剂1.5%)的降雨产流过程,基于37次模拟降雨实验,归纳了降雨产流的一般过程、规律和特性,分析了降雨强度、基质厚度和基质初始含水率对简单屋顶绿化滞流蓄水特性的影响。结果表明:基质厚度和基质初始含水率对简单屋顶绿化的蓄水特性有显著影响,基质初始含水率越低、基质厚度越厚时蓄水特性越佳。建立了产流时间数学模型,简单屋顶绿化降雨产流时间与降雨强度呈负相关,同时也受初始含水量和基质厚度影响。随着干湿循环次数增加,基质的厚度总体呈现下降趋势,储水性能逐渐下降,延迟产流时间逐渐缩短。

An artificial rainfall device and a data acquisition system are designed to study the rainfall-runoff processes of an extensive green roof with matrix of 57.0% ceramsite,41.5% peat,and 1.5% super absorbent polymer.Based on 37 times artificial rainfall tests,the fundamental processes of rainfall infiltration and runoff are illustrated.The effects of rainfall intensity,matrix depth and initially water content on the rainwater retention features are studied.The results show that the effects of matrix depth and initially water content are significant.The rainwater storage in matrix will increase with lower initially water content and higher depth.A multiple linear regression equation is presented for the delayed time of runoff.It shows that the delayed time of runoff is negative related with rainfall intensity.Meanwhile the delayed time of runoff are affected by initial water content and depth.With the increase of wetting and drying times,the matrix depth tends to decrease,the rainwater storage gradually declines,and the delayed runoff time tends to shorten.