Research On Annual Runoff Control Rate Evaluation Method Based On Sponge Module

The annual runoff control rate is an important inspection index for the current acceptance of sponge city construction.The existing evaluation method of this indicator has the problems of limited evaluation scope and high monitoring difficulty.In view of the above problems,this study replaces regional monitoring with sponge module monitoring to study the runoff control effect of the single sponge module and the combined binary sponge module and its parameter values in the model.Control rate-weighted sponge city annual runoff control rate evaluation method,and applied research in pilot areas.Taking the single sponge module as the research object,using Morris screening method and artificial trial and error method,combined with simulated rainfall device and field monitoring,it has runoff control on permeable pavement,green roof,sunken green land,biological retention facility and water storage facility,etc.The typical single-sponge sponge module is used for parameter selection,calibration and runoff control effect evaluation.The results show that with runoff and peak runoff as response indicators,the sensitive parameters of permeable pavement are pavement layer thickness,hydraulic conductivity,impervious surface,and clogging factor,and the annual runoff control rate of its single facility is about 30%,biological retention The sensitive parameters of the facility are surface water storage depth,soil field water holding capacity,soil layer porosity,soil withering coefficient,and soil layer thickness.The annual runoff control rate of the single facility is about74%,the sensitive parameter of the green roof is the surface Water storage depth,soil layer thickness,soil layer porosity,and soil field capacity,the annual runoff control rate of its single facility is about 45%,the sensitive parameters of submerged green land are surface water storage depth,depression slope,and The annual runoff control rate of a single facility is about 42%.Using the same method as the single sponge module,the three typical binary sponge modules for permeable pavement and biological retention zone,permeable pavement and submerged green land,green roof and submerged green land are used for parameter screening,rate determination and runoff control effect evaluation.The results show that: when facilities are combined,the sensitivity levels of the parameters of the combined facilities in the SWMM model will not change,at an area ratio of 0.5-8 in the binary module,the annual runoff control rate of permeable pavement and biological retention zone is Variation within 69%-40%,annual runoff control rate of permeable pavement and sunken green space varies within 50%-36%,annual runoff control rate of green roof and green space varies within 52%-45%.Based on the above research results,the implementation process of the sponge city-based sponge city annual runoff control rate evaluation method was studied and applied in the pilot area.An evaluation process of research area investigation,drainage area division,construction area statistics,determination of typical underlying surface control targets,evaluation result calculation is formed.The pilot area was evaluated,and its annual total runoff control rate was 40%,and compared with the monitoring simulation method evaluation results,the difference was only4%,indicating that the sponge city-based annual urban runoff control rate evaluation method can be effective The annual runoff control rate assessment of the area.