城市土壤特征对降雨径流控制的影响

城市范围土壤受到人为扰动而出现生态功能退化,总结了城市土壤的物理化学和水文生态特征,分析了城市土壤对降雨径流量和水质的影响,探讨了低影响开发(LID)工程土的要求,以期为改善LID措施控制降雨径流效果提供理论依据和参考。研究表明:以下渗为主的LID措施,土壤饱和导水率是重要参数;以去除污染负荷为主的LID措施,土壤质地、容重是重要参数,pH及本底养分、重金属含量也是影响因素;应以此为基础设计改良工程土配方;施工过程中,应避免场地土壤的机械人为压实;定期清理设施区域的垃圾,防止阻塞土壤表层;在污染严重区域,定期检测土壤污染物浓度,若超过土壤负载需更换土壤。

Influence of Urban Soil Characteristics on Stormwater Runoff Control

: The characteristics and ecological functions of urban soil are degraded by human activities. The influence of urban soil characteristics on stormwater runoff quantity and quality is analyzed, the requirements of LID engineering soil is discussed, so as to provide theoretical basis and reference for improving rainfall runoff control effect of LID measures. It is showed that the saturated water conductivity of soil was an important parameter for LID measures mainly focused on infiltration. For LID measures mainly aimed at removing pollution load, soil texture and bulk density are important parameters, and pH value, substrate nutrients and heavy metal content are also influencing factors, based on which the engineering soil formula should be improved. During construction, mechanical compaction of soil should be avoided. The garbage in LID facility area should be regularly cleaned up to prevent blocking soil surface. In heavily polluted areas, soil pollutants should be periodically checked, and replaced if they exceed the soil load.