Based On SWMM Simulation Study On Hydrological Effect Of Low Impact Development In Luxi New Town, Xixian New District

Urbanization is often accompanied by many environmental problems. Due to land development of city while urban water scarcity, the original state of the underlying surface was artificially changed that led directly to urban runoff coefficient increases, increased runoff and cities waterlogging disasters, such as floods.Low Impact Development (LID) mode provides a way that to solve water scarcity and rainy urban waterlogging disaster in the city. In recent years, good urban hydrological cycle patterns by urban rainwater infiltration, stagnation, storage, clean, use, discharge and other means that has widely studied and utilized in the field of urban stormwater control at home and abroad.This paper took a part of Fengxi new town in Xi'an and Xianyang district as the study area, through inquiring information, field research and using storm water management model (SWMM) for modeling, and also respectively simulated the regional status and hydrological effects after deployed LID facility (sunken lawn, rain gardens, permeable paving, green roofs and rain barrels).The main findings are as follows:(1) This study proposed that to introduce a low impact development model in the study area for the current urban water problems after researched the current domestic advanced stormwater management model.(2) Storm sewer system of the study area was generalized. The author introduced the principle of modeling SWMM and used it for the study area by a simple rainwater pipe network model in Fengxi new town of Xi'an and Xianyang district.(3) Discussed the selection principles and requirements for a variety of LID facilities in stormwater system, and also suitable LID facilities was selected into the simulation model for regional situation.(4) After studying on the simulating of two scenarios that regional status and LID pattern, the author found it is the LID combination in various return period rainfall that P= 0.5, P= 1, P= 2, P= 5, P= 10, P= 20 and so on that was able to effectively improve the underlying hydrology environment in study area, reduce runoff coefficient, reduce runoff peak flow, delay the peak arrival time, effectively reduce rainwater drainage pipe network pressure and reduce stormwater system expansion costs.