绿色屋面对雨水径流控制效果及影响因素

Experimental study on performance and its influence factors of green roof on stormwater management

为了评估杭州地区绿色屋面对雨水径流的控制效果,提出基于实测数据进行对比分析和统计分析的方法.建立7个绿色屋面装置和1个非绿色屋面装置,一年内连续监测降雨、屋面的径流流量特征以及屋面的水分蒸腾量(2016年2月-2017年3月).根据土壤水分蒸腾速率的变化规律,分段进行绿色屋面截留率的多元回归分析.结果表明:相比于非绿色屋面,绿色屋面能够有效减少屋面径流量,截留率均值高达53%~62%,径流峰值平均削减50%,延迟8min.绿色屋面的截留效果不仅受屋面坡度、基质和是否栽种植物的影响,还与降雨深度、前期干燥天数(ADWP)显著相关.分段回归分析大大提高了回归模型的预测精度.

A comparative analysis and statistical analysis was developed based on experimental data to evaluate green roof performance on stormwater runoff control under Hangzhou climate conditions.Seven different green roof setups and one conventional roof setup were constructed.Rainfall,runoff and evapotranspiration（ET）data from the setups were collected over a year from February 2016 to March2017.The period was divided into stages according to the evapotranspiration rate,and multiple regression analysis was developed for each stage,respectively.Results indicate that the green roofs can effectively reduce 53%-62% runoff volume,lower the runoff peaks by 50% and delay the peak runoff by 8 min compared with the control roof.Runoff retention is significantly affected by roof slope,substrate,plants,rainfall depth and the antecedent dry weather period（ADWP）.The prediction accuracy of the regression model was improved by the regression analysis in stages.