北京雨水管控体系下年径流总量控制率实现效果分析

Analysis on the Realization Effect of Volume Capture Ratio of Annual Rainfall under the Existing Rainwater Management and Control System in Beijing City

北京市基于地方标准《雨水控制与利用工程设计规范》(DB 11/685-2013),提出了“3、5、7”的雨水管控措施体系,并以水影响评价审批制度为抓手,确保实施效果。为探讨该体系能否满足海绵城市建设对年径流总量控制率的要求,综合采用公式计算、实测数据分析和数值模型模拟3种方法进行分析。结果表明,现有雨水管控体系是从源头推动海绵城市建设的有效措施,可以在地块层面上实现年径流总量控制率不低于85%的控制目标;单纯依靠地块层面上的管控措施,无法在建成区实现区域层面的海绵城市建设目标;老旧小区开展海绵化改造受各种因素制约,改造效果并不理想。为此,建议在现有管控制度的基础上,进一步强化规划层面上的雨水管控;增加对面源污染负荷削减、雨水资源利用等指标的管控要求;探索基于水影响评价制度的海绵城市管控体系,并先期在通州国家海绵城市试点区试行。

Based on the Beijing local standard of Code far Design of Stormwater Management and Harvest Engineering ( DB 11/685-2013 ),"3, 5 , 7 " rainwater management and control measures system were proposed, and water impact assessment system was applied to achieve good results after implementation. Under the background of sponge city construction, whether the system can meet the requirement of volume capture ratio of annual rainfall needs to be clarified. Three methods, namely the formula calculation, field data analysis and numerical model simulation, were used to analyze this question. The results showed that the existing rainwater management and control system was an effective measure to promote the construction of sponge cities from the source. It could achieve the target of volume capture ratio of annual rainfall not less than 85% at the lot level. It was impossible to achieve the target at the regional scale by simply relying on rainwater management and control system at the lot level in built-up areas. The sponge transformation in old communities was limited by various factors, and the effect was not ideal. It was suggested that the rainwater management and control system at the planning level should be further strengthened, the indicators such as the reduction of surface pollution load and the utilization of rainwater resources should be added in water impact assessment system in Beijing, and the sponge city management and control system based on Beijing water impact assessment system should be explored and applied in the Tongzhou national sponge city pilot area.