Studies Of Urban Rainwater Utilization

As China's economy and the rapid development of urbanization, the increasing number of cities, expanding the scale of the urban population and economic activity is highly concentrated, leading to a serious shortage of urban water resources, urban underlying surface conditions are constantly changing, impervious area expansion caused by rainwater runoff coefficient increases, runoff increases, urban stagnant water lasted shorter, a lot of rain run-off through the sewer discharge into the river within a short time to focus and increase pressure on the city as well as the confluence of river flood-type drainage network drainage pressure on the river crest of peak increased and the peak is now ahead of schedule, resulting in urban flooding problems have become increasingly prominent. In addition to rainwater resources, we should be given adequate attention and rainfall rational development and utilization of resources can achieve its objectives to save water, water conservation, to control soil erosion and water logging, to reduce the load of urban drainage, water treatment systems and water pollution, recharge groundwater, to ease a series of ground subsidence caused by urbanization, the three major water issues, namely, water shortage, water pollution, urban flooding. That can be said to make full use of urban rainwater resources to solve China's urban floods, droughts, water shortages and urban water pollution and achieve sustainable development of cities to ensure the factors.In this paper, the basic theory and system analysis and research on urban rainwater resources based on a wide range of access to information about domestic and international urban rainwater utilization of resources, mainly including urbanization on urban hydrology and urban ecological environment, the concept and characteristics of urban rainwater resources as well as the relationship between with urban development. The domestic and foreign resource utilization status of urban rainwater, as well as the latest research and technological achievements, the final system described in the current use of rain water utilization key technologies.The first step of Urban development and utilization of the rainwater resources is analysis and evaluation of potential of the rainwater resources, and the results determine the feasibility and rationality of rainwater resources, this paper proposed by Chinese scholars ZHAO Ke-qin 1989 Uncertainty Analysis -- set pair analysis, is proposed based on set pair analysis of regional development and utilization of rainwater resources potential of a comprehensive assessment of resources in urban life from the rain water, agricultural irrigation and industrial areas the proportion of objective evaluation of the implementation of urban development and utilization of rainwater resources potential.Another key part of urban development and utilization of the rainwater resources and forecasting of water resources, hydrological forecasting is often necessary to forecast urban rainfall. This paper presents the analysis of rainfall prediction and its applications based on set pair analysis. Set pair analysis method can be used to quantificationally compute the similarity between the nonce and history collections from the views of identical, discrepant and contrary sides, the most similar samples regard the standardized self-correlation coefficients as weights which reflects the relationships of the nonce and history rainfall, then get the forecast.