Adaptability Analysis And Countermeasure Research Of Urban Stormwater System By The Future Precipitation Change

Under the background of global warming,flood,drought,and other extreme climate events tend to become stronger.The status of urban waterlogging prevention and control is becoming more and more prominent,and it is very important to deal with the planning and design of urban stormwater management system in the future.How to predict and respond to the impact of future extreme climate events on urban stormwater management system has become a crucial task.Therefore,aiming at the impact of future precipitation change on urban stormwater system,we will combine climate change with urban stormwater management system.Taking a complete and typical confluence system in Zhuanghe of Dalian as an example,it is made a statistical analysis of the historical measured precipitation data in Zhuanghe,so as to effectively determine the location of precipitation and rain peaks of the storm in Zhuanghe.Second,the precipitation data in the Zhuanghe area are interpolated by the NCC/GU-WG 2.0 for nearly 100 years,because of the short detection time of the precipitation data in the Zhuanghe area.Wavelet analysis is used to analyze the law and the cycle of precipitation change in Zhuanghe in the lastest 100 years,and predict the trend of precipitation in the future,fitting the 3a precipitation process of the future Zhuanghe area,combining with the Info Works ICM urban hydrological model,and evaluating the urban stormwater system capacity in the region based on the present situation and the future precipitation change,and the simulation of the urban stormwater system capacity in the region.In order to provide some reference for future urban planning and construction in China,a relatively better urban stormwater management system adaptation plan and Countermeasures for future precipitation change is drawn up.The results show that the annual precipitation in Zhuanghe has a weak upward trend,and 60% of the historical rainfall is single peak rain.After statistics,the peak value appears at 47 persentage in the overall process and similar to the rain type No.I.The average historical duration is 694 min after the statistics of all the rainfall events.The annual average precipitation in Zhuanghe area in the next 100 years is 773 mm.After a series of wavelet analysis,it is found that rainfall will be changed by the precipitation cycle of 18 a and45a in 2017.In the period of the change of 45 a,the annual precipitation may rise greatly,causing great pressure to the city stormwater management system,when carrying out the construction of Major drainage system of storage facilities,the correction coefficient should be considered as 1.1,so as to effectively cope with future rainfall changes.Through the current situation assessment,the drainage area of the Zhuanghe drainage area is mostly0.5~1a,unable to meet the current urban drainage task and can't meet the 3a drainage standard,so the urban stormwater system in this region needs to be upgraded at once,the current 3a precipitation and the future 3a water drop into the current model are simulated to find out the number of waterlogging points caused by the 3a precipitation in the region in the future.The proportion of the amount,the deepest waterdepth,the total area of the waterlogging area and the overloaded state of the pipe network are all higher than the influence of the current 3a precipitation.Therefore,under the situation of the future precipitation change,if the urban stormwater system is upgraded according to the current 3a precipitation standard,the drainage standard of the future 3a precipitation can't be reached during the future precipitation situation.In view of the change of 3a precipitation in the future,6 sets of urban stormwater system upgrading schemes for the two kinds of urban drainage systems for the drainage area in Zhuanghe are formulated.The project of source transformation & terminal storage construction project is relatively high economy and has a certain water quality improvement ability,which can reduce 35% of the pollutants,and reduce 20% of the volume of runoff,the total annual runoff control rate can be promoted to a certain extent,the close to the space of the project is larger in the near and long term,although the confluence drainage system is short In the period of time,the drainage requirements for future rainfall can be achieved.But for the long-term consideration,the diversion system scheme of the diversion system of the source transformation & conduit system & the terminal storage construction should be constructed in stages.Although the project has the largest investment in the project,the water quality improvement effect is the best,the pollution reduction rate can be over 70%,and it can be improved syntheticallyThe most effective construction method to deal with the future precipitation change of the urban stormwater drainage system is improve as these way: make the municipal infrastructure is transformed to the LID infrastructure,with the construction of the terminal storage facilities,the joint flow system is gradually diverted and transformed in the long term,and the urban stormwater system in the region is gradually green transformation,so that the urban stormwater drainage system can reach the future 3a rainfall event.It meets the drainage requirements under the scenario of future precipitation change to adapt to the change of precipitation caused by future climate change.