Research On Urban Flooding Control Based On Cause Analysis

In recent years,the systematic management of urban flooding has gradually been put on the agenda,and it is urgent for cities to formulate corresponding urban flooding management plans according to the actual local conditions.In accordance with the "Implementation Opinions of the General Office of the State Council on Strengthening the Control of Urban Flooding ",this paper takes cities as organic living bodies and builds sponge cities and resilient cities,and proposes a governance method based on the analysis of the causes of flooding to promote the systematic management of urban flooding.Research.According to human causes,urban flooding can be divided into topographical causes of unreasonable land development,underlying surface causes of altered natural runoff processes,and management causes of inadequate implementation of relevant systems and standards for flooding control.This paper conducts special research on the governance of urban flooding points for each cause,and integrates their respective research results to provide a reference for the systematic governance of urban flooding.The main contents and innovations of this paper are summarized as follows:(1)This paper proposes a method for identifying the urban flooding points of the geomorphic causes.It uses the GIS hydrological modeling technology to carry out the overlapping analysis of hydrological analysis,inundation analysis and TWI analysis on the DEM map of the study area.The intersection of the confluence and the low-lying area is used as the identified urban flooding point.The results of comparing it with the actual investigation of the urban flooding point show that this method can be used to identify the urban flooding point caused by the terrain.The treatment methods for the urban flooding points of such macroscopic causes are as follows: truncate the external confluence path in the area to block the impact of external confluence on its urban flooding,sponge the interior of the area where the urban flooding point is located,and reduce rainfall runoff in this area.(2)The urban flooding model of the study area was constructed through Infoworks ICM to explore the best way of "combining gray and green facilities",and to obtain the best control plan for the urban flooding caused by the local underlying surface in the study area.In this paper,a combination scheme of green roof and drainage pipe network is selected to achieve the above purpose.The results show that the drainage of the drainage pipe network plays a major role in the urban flooding control caused by the local underlying surface,and the green roof plays an auxiliary role.In a larger area,the role of green roofs is also very important.The complementary advantages of the two can achieve effective control of local underlying surface urban flooding.The best combination should be to strengthen the construction of green roofs in the sub-catchment area and the most upstream area of the drainage network at the urban flooding point.(3)Through the literature survey,it is found that the management system and standards of urban flooding have been relatively perfect,but urban flooding still occurs frequently,and it is urgent to solve the urban flooding caused by management causes.Comprehensively considering the spatial relationship and management status of urban flooding points of various causes,a management plan of zonal quantitative drainage is proposed for urban drainage.Allocate the allowable drainage volume of each upstream community to manage and control the drainage volume in the upstream area of the urban flooding points,so as to realize the refined control of urban flooding.In the follow-up,it is necessary to strengthen the supervision and management of systems and standards and personnel training in related fields.Through the research in the above three aspects,it can be found that the urban flooding points caused by the geological formation with difficult governance and wide catchment range have been transformed into the urban flooding points caused by the underlying surface.Under the standardized urban flooding management,the systematic management of urban flooding can basically be realized.