Research On Collection And Utilization Of Rainwater In Building And Residential Area

In China, various water resources problems continuously occurs. Not only water shortage and pollution, but also issues related with water ecological environment, have become a social core problem which is now the main bottleneck restricting sustainable development of economy and society. Besides, in the continuous urbanization, with the expanding urban hardening area year by year and the increase of areal runoff coefficient,the flood season runoff and peak have been increased significantly, which is prone to waterlogging. If much attention could be paid to rainwater collection and the use of engineering method to make full use of rainwater resources, the exploitation of groundwater can be reduced with the groundwater to be covered, which can also minimize urban flood disaster with ecological environment improvement. Therefore,from the perspective of sustainable utilization of urban water resources point of view,collecting and reusing rainwater effectively will be an important measure.Water resources are not limited to river and ocean that we can see. How to make full use of rainwater resources becomes a key point that attracts many people currently.There is a concept that called impervious area. It is roofs of buildings that occupy a large proportion of total impervious area. Rainwater collected from roofs is easier to be cleaned and the quality is much better than that collected from other places. At present,the urban rainwater utilization is mainly focused on the residential area, and in water conservancy engineering, current rainwater collection system don't have enough supportive research and engineering practice in construction area.As a part of the rainwater harvesting system, siphon-type roof drainage system,with its unique technical advantages and characteristics, has been widely used in the large roofs of public buildings, workshops and warehouses. However, whether or not it can be applied to the roofs of small buildings is worth to further analysis and research.This paper mainly researched on the problems of rainwater utilization in the architecture and community. Based upon the deep learning of both domestic and foreign advanced rainwater utilization, according to the design specification, this paper analyzed the type of rainwater collection and utilization, the water quality and affecting factors at initial stage of rainfalls, the water balance of recycling system(including thecalculation of water consumption, collection and abandon), as well as the rainwater recycling treatment technology. The measures of rainwater abandon flow are expounded,the volume of rainwater tanks is determined and the feasibility of rainwater collection and utilization application in small type construction area of water conservancy engineering is demonstrated. The results will have a reference effect in other similar project design of rainwater collection and utilization.This paper also presented the study results related to principle of pressured flow(siphon type) rainwater drainage system, the flow pattern, the key point of hydraulic calculation, design steps and methods. By compared with the technical economy of gravity-type rainwater drainage system, the paper summed up the feasibility of the application of the pressured flow(siphon-type) rainwater drainage system on small roof, which provided scientific basis for choosing drainage system in similar other projects.