机构地区:[1]北京建筑大学城市雨水系统与水环境教育部重点实验室,北京100044 [2]北京建筑大学北京未来城市设计高精尖创新中心,北京100044 [3]北京建工建筑设计研究院,北京100044 [4]北京建筑大学建筑与城市规划学院,北京100044
出 处:《环境工程》2020年第4期83-88,共6页Environmental Engineering
基 金:国家自然科学基金面上项目“建筑与小区绿地的径流削减效果影响因子及径流系数研究”(31870704);北京未来城市设计高精尖创新中心资助课题(UDC2016040100)。
摘 要:土壤渗透性是影响雨水入渗的关键因素之一,是分析土壤蓄积雨水能力的重要前提条件。针对目前城市绿地土壤渗透性能实测数据缺失、评估方法单一、指标选取较少的现状,采取实测法获取北京不同城市功能区的绿地土壤渗透速率、孔隙比、含水率等数据,并采用相关性、因子分析和多元线性回归分析法,分析影响城市建筑小区土壤渗透性的主要因素,探索建立精度更高、数据需求量更少、计算时间更短的土壤渗透模型。运用该模型得到北京市城市绿地雨水入渗能力水平,建立土壤-降雨产流之间的联系,得到以实测数据为基础,更贴近实际产流过程的径流系数。结果表明:试验样地内3种功能区土壤渗透性能排序为:居住区>文教区>商业区,实测入渗曲线均符合霍顿渗透模型;土壤内部因素中孔隙比、初始含水率和初始入渗速率三者相互关系紧密,外部因素中植被覆盖度与人为干扰情况呈强负相关,考虑到内外部因素共同作用,初始入渗速率可与初始含水率和植被覆盖度建立初步线性关系式(R^2>0.9);入渗量对雨量径流系数的影响随着降雨量和不透水区域面积比例的增大而减小,入渗量占年径流总量控制率对应的降雨量的比值为37.6%~58.2%,并与降雨量呈负相关。研究结果可为海绵城市建模和下垫面优化设计提供理论参考。Soil permeability was one of the key factors affecting rainwater infiltration,and also an important prerequisite for analyzing the ability of soil to storage rainwater.In view of the current situation that the measured data of urban green space soil permeability was missing,the evaluation method was rare,and the index was insufficient,this paper obtained the data of soil permeable rate,void ratio and moisture content of different urban functional areas by using the actual measurement method.Correlation analysis,factor analysis and multiple linear regression analysis were used to analyze the main factors affecting the soil permeability of urban communities,and exploded to establish a soil permeability evaluation model with higher precision,less data demand and shorter calculation time.This model was used to obtain the infiltration capacity of urban green space rainwater in Beijing,establish the relationship between soil and rainfall-runoff,and get the measured data-oriented,closer to the actual runoff coefficient.The results showed that the soil permeability of the three functional areas in experimental plots were in order of residential area>cultural and educational area>commercial area,and the measured infiltration curves were all consistent with the Horton model.The void ratio,initial moisture content and initial infiltration rate of the internal factors of the soil were closely related to each other.The degree of vegetation coverage in the external factors had a strong negative correlation with human disturbance.Considering the combined effect of internal and external factors,the initial infiltration rate could establish a preliminary linear relationship with initial moisture content and vegetation coverage(R^2>0.9).As the proportion of rainfall and impervious area ratio increased,the infiltration amount had smaller impact on runoff coefficient.The ratio of infiltration to rainfall corresponding to the total annual runoff control rate was between 37.6%and 58.2%,and it was negatively correlated with rainfall.Th
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