Research On Outdoor Environment Design Of Zhengzhou Residential District Based On Sponge City Theory

In the wake of expedited urbanization in China in the 21 st century,issues such as urban water logging,water shortage and water environmental pollution appear to be increasingly standing out.In the context of policies for sustainable development at the macro level,scholars in China have proposed the concept of “sponge city”,claiming that a city should act as resilient as a sponge to deal with rainy weather in a way that it can store stormwater when it rains and release and utilize the water whenever necessary,with the functionality of self-purification.Residence areas,accounting for a high percentage in urban construction,form a critical link in the urban ecosystem.However,it turns out that the existing fast stormwater drainage for the residence areas fail to tackle severe urban water issues,impelling the progressive transition to the stormwater management model claimed by the sponge city concept,namely,“governance at source,reduction in process and controlling in the end”.With regard to outdoor residential environment design,according to the new standard,it is required to take into account of a systematic stormwater management approach integrating “permeation,storage,stagnation,purification,consumption and drainage”in one;it is also crucial to combine professionalism of such disciplines as architecture,landscape and water supply & drainage,properly arrange roads,green space and squares,and give play to stormwater permeation,storage and purification functions of the sponge facilities,so as to maintain or regain natural hydrologic cycle that existed before the site development to the utmost extent and eventually for sustainable and integrated management of stormwater in outdoor environment of the residence areas.The paper,targeted to outdoor environment of residence areas,firstly starts with a summary on sophisticated stormwater management theories and practices outside China,goes through how stormwater management of foreign residential complex has evolved,uncovers what is underlying the evolution and identifies what tallies the foreign stormwater management practice and experience with outdoor environment of residence areas in China.The paper,then,systematizes history of stormwater management for residence areas in China,comprehensively analyzes what the sponge city concept means to the construction of residence areas,and eventually studies excellent practices in this respect.All these will serve supportive,theoretically and practically,for future outdoor environment design of residence areas.Secondly,this paper presents discussions over effects of climatic environment,topography and landform,soil,and other factors on stormwater management in an outdoor environment.Field survey on status quo of stormwater management in residence areas in Zhengzhou discovers issues and helps acquire related experience in construction.The feasibility of the sponge city concept in the outdoor environment is analyzed by referring to related local management measures for sponge cities.Moreover,concrete design strategies for the stormwater management in an outdoor environment is delved into,from such micro-level perspectives as roads,landscape,squares and parking lots,so as to further optimize what is covered in design of residence areas in sponge cities.Last but not least,the present paper case studies the top talent apartment neighborhood of Henan Provincial Pharmaceutical Innovation and Transformation Base.In specific,it provides performance evaluation and general analysis on three stormwater management models,namely,traditional model,economical model and the optimal model,by using a SWMN hydrologic model and simulating various precipitation scenarios,based on acquired measurements,engineering data and related norms and according to control targets and design standards of the country and Henan Province.Comparison over pros and cons of the three proposals concludes the most feasible one for outdoor environment design of the residence area,which can tackle exiting water issues,and construct a systematic and coordinated stormwater management model for the outdoor environment.To sum up,the ultimate findings are believed to serve as a reference for design and study of Zhengzhou residential sponge city based on the sponge city concept.