Research On The Measures And Impacts Of Low Impact Development For Urban Areas

By gradually accelerating process of urbanization, land layout has changed a lot. Thetransition from a native landscape to a built environment increases the impervious surfacecoverage of roads, parking areas, sidewalks, rooftops, and landscaping. These changes reduce,disrupt or entirely eliminate native vegetation, upper soil layers, shallow depressions, andnative drainage patterns that intercept, evaporate, store, slowly convey, and infiltratestormwater. As development progresses, the hydrological characteristics of the area in smallwatersheds have been changed and the natural water cycle have been destroyed. As a result ina series of problems of urban water environment. Conventional stormwater managementwhich dominated by the end treatment has already can’t meet the requirements of thesustainable development of our city. The low impact development (LID) approach combines ahydrologically functional site design with pollution prevention measures to compensate forland development impacts on hydrology and water quality. It will be a new tool to solvingwater environmental problems of urban areas.This paper analyzes the problems of water environment in the urban and reasons ofincreasingly serious water-logging. By reviewing the connotation, the core idea characteristicsof LID, comparative analysis between LID and traditional stormwater managementtechnology and BMPs reveals that LID is a kind of more economical, more simple,environmental protection stormwater management technology. On the basis of further studyof LID typical technological measures and construction, the author uses the SWMM modelsimulating the runoff coefficient and the runoff peak of different land layout with differentrepetition period of rainfall. Results showed that the higher urbanization, greater runoffcoefficient, lower flow duration time, greater variation in flow magnitude; and LID caneffectively maintain runoff volume and reduce flood peak, especially facing rainfall eventunder0.1-year and2-year; and subcatchment with rain garden and infiltration landscapeareas (HSQ3) is more effective than other subcatchments (HSQ4, HSQ5, HSQ6),whichproves that LID integrated practice is more effective than single LID control. As a conclusion, by comprehensive analysis and deep research, LID technology hassignificant theoretical and practical value to improve the state and level of urban development,and SWMM model has important application to analyze the effect of LID.