The Coordination Between The Spatial Distribution Of The Green Infrastructure And The Active Rainwater Pipe Network On The Site

With the rapid development of the city,the natural hydrological characteristics of the surface have changed and the impervious surface area is continuously increasing.The heat island effect becomes seriously and the comprehensive runoff coefficient gradually becomes larger,resulting in the runoff of the surface increasing,the peak of the runoff advance,the active rainwater pipe network cannot meet the emission requirements of the site.At the same time,cities are often faced with the water shortage in the process of the development.In this context,the Green Infrastructure(hereinafter referred to as GI),which uses natural means to deal with the rainwater,was born.By planning the GI on the site,the rainwater emission mode is changed from the fast emission to using the GI to remain and store the rainwater,and it can be used when the site needs it.But the GI planning method of our country does not consider the advanced rainwater control technology together with the active rainwater pipe network.The planning method of the GI to deal with the rainwater of the site and the active rainwater pipe network are separated.And the coordination between the spatial distribution of the green infrastructure and the active rainwater pipe network needs to be lucubrated.This paper analyzes the insufficient discharge capacity of the active rainwater pipe network and the reasons for its overflow by analyzing the catchment basin and the layout of the active rainwater pipe network,combined with the analysis the change of the land use and the change of the rainfall,according to the traditional design pattern of the rainwater pipe network.Design the scale of the GI construction based on the maximum increase in the field intercept ability and the lowest cost of the GI by analyzing the types and functions of the GI.Calculate the benefit-cost Pareto frontier of the GI construction scale by using the NSGA-Ⅱ algorithm,and then determine the construction scale of the GI which the site needs.The GI construction scale scheme is optimized by the rainfall distribution plan between the catchments based on the overflow.The spatial coordination design(including the coordination in the plane and the vertical)between the GI and the active rainwater pipe network by analyzing the plane and vertical characteristics of all kinds of the GI based on the overall layout of the current situation,combining with the analysis of the pipeline and the gutter inlet of the active rainwater pipe network on the ground,in order to make them work together and complete the mission of collecting,storing,purifying and reusing rainwater in the city.This paper gives an example of the south college of Xi ’an University of Architecture and Technology.Redesign the scale of the rainwater pipe network and calculate the overflow,and design the GI construction scale based on the multiple objective,the analysis results show that a certain scale of the GI can promote the intercept ability of the site economically.The construction scale of the GI is optimized according to the rainfall distribution plan between the catchments based on the overflow.Analyzing the catchment 13,include the roads,afforest,buildings and impervious areas,according to the plane and vertical properties of the GI,combined with the analysis of the pipeline and the gutter inlet of the active rainwater pipe network on the ground,and then make a spatial collaborative plan between the GI and the active rainwater pipe network,and finally achieve the goal of highly and efficiently deal with the rainfall.