Study On The Influence Of Different Land Use Patterns On Rainfall RunoffPollution

In recent years, with the rapid urbanization progress, the proportion of urban pervious area accounts for more and more low, especially the blind pursuit for "Metro" model of wide roads and large neighborhood, result in more unreasonable urban land use pattern, thereby exacerbated the trend of individual motorized travelling, more and more vehicles crash into the city center, causing increasing traffic congestion, but also led to water pollution and public health crisis.Road as the main underlying face of the city, with the rainfall runoff erosion, makes legacy on pavement SS, heavy metals, organic matter and PAHs and many other substances directly with the road of rainfall runoff erosion into receiving waters, causing eutrophication aggravation and water environment ecological system destruction, which becomes the important influence of the pollution source on water environment quality. With the rapid growth of the volume of motor vehicles in Hangzhou city, urban road runoff pollution is increasingly serious. Therefore, study on relationship between the pattern and rainfall runoff pollution in different land use can control and manage the urban non-point source pollution, at the same time, improving the water quality of urban river has important significance.This paper takes Hangzhou as the research object, combined with the existing regulatory management unit division, selected Hangzhou Wenxin, Tang Bei, Cui Yuan, Gu Dang, Zhao Hui, Da Guan and Gong chen bridge as 7 regulatory management units. Based on the land use classification, draw out 7 research units of land use map, and select the density of road network, non traffic road network density, traffic road transit site density, non traffic road transit site density, residential ratio, non traffic road shops along the street length ratio to analyze the characteristics of land use pattern. At the same time, a total of 6 games at the beginning of rainfall runoff water quality on the 2014 March to 2014 July, each unit is monitored, selected on the basis of SS(suspended solid concentration), CODCr(chemical oxygen demand), TN(total nitrogen), Pb four indicators to characterize the initial rainfall runoff pollution,analyzing the characteristics of rainfall runoff pollution and its relationship with land use pattern index by using the software of SPSS, revealing the land use pattern and mechanism of water environmental influence, to explore the city road traffic layout and possible approaches of land use structure optimization and strategies, in order to provide decision-making basis for the research and management of city road runoff pollution. The main conclusions of this paper are follows:(1)Among the seven units road initial diameter water quality involved in the study, besides the Gong chen bridge unit size water quality is relatively good, other units are more than inferior to V class water standards with poor runoff quality.(2)Except the TN as the major pollutants of Road runoff at the primary stage is mainly from atmospheric deposition, other pollutants are all from road runoff and the pollutants have significant relationship. Therefore, by the effective removal of SS can reduce the initial road runoff pollution.(3)The non traffic road bus station density and water quality indicators showed a significant negative correlation, indicating that the increase of non traffic road bus station density can help to improve road diameter water quality to the decisive role. In the future planning we should give priority to the bus station which is set in non traffic roads, and prompt people to choose to travel by public transport.(4)High density networks can effectively disperse traffic flow and alleviate runoff pollution especially the poor traffic road network to improve the unit internal regional accessibility, effectively inhibit the frequency of use of motor vehicles, and create a good travel environment for walking.(5)Balanced commercial ratio and non traffic road shops along the street length ratio have the ability to achieve regional vocational balanced living and reduce cross commuting, prompting residents nearby shopping and employment, to ease the traffic pressure, and reduce the concentration of pollutants in the water quality of diameter.