Study On Optimal Selection And Application Strategies Of Rainwater Utilization Techniques In Jing-jin Area

With the rapid development of urbanization, many cities in our country arefacing the problems of water shortage and pollution. As a crucial part of natural watercirculation system and water environment, storm water utilization can alleviate theshortage of clean drinking water, and help improve the regional ecological balance.Besides, it can help establish a virtuous water cycle and achieve sustainabledevelopment of water resource. So in recent years, much more attention is beingattached to rainwater utilization.During the research, an investigation was conducted on the current situation ofrainwater utilization in Jing-Jin Area. The results revealed that roof, road andgreenbelt surface are usually used as the underlying surface to collect storm water,adopting ecological technologies as the major techniques. The reclaimed rainwater isoften used to recharge the groundwater; few projects used the reclaimed rainwater asgrey water.Based on the survey, analytical hierarchy process (AHP) and multi-objectivedecision-making model were utilized to select an optimal technical program. First,following scientific, systematic principles and the combination of both qualitative andquantitative indexes, an evaluation system was constructed, which consists oftechnological, economic and environmental indexes. Then, the weights of criterialayer and index layer were determined through AHP, and the results showed that thewater quality, the application potential and the cost of the techniques are the top threeindexes. Last, the optimal program-ecological rainwater utilization technologies, wasobtained by multi-objective decision-making model.Based on the optimal technological program, application strategies wereanalyzed from technological level and political level. In technological level, atechnological system was constructed, which includes various ecological technologies,such as sunken green space, bioretention, permeable pavement and so forth. Thesemeasures were arranged in different urban spaces in Jing-Jin Area such as urbantraffic, urban residential areas and parks. In political level, we explored the policiesand regulations from many aspects, including the discharge license, economicincentives, the construction of governing bodies and so on. The atmosphere was formed which is beneficial for the application and development of the selectedtechnologies.