Research Of The Impact Of Varying Conditions And Rainwater Resources Utilization On Water Supply In Dalian

Dalian is a resource-based city with serious water shortage issue.According to the existing water resources allocation program,water supply and demand gap is huge in 2030 because of the 430 million-m3 water supply shortage.However,the main way to solving the water supply shortage is to rely on transfer water or seawater desalination instead of taking rainwater resource into consideration.At the same time,the impact of climate change and human activity on water resources is becoming stronger and stronger in recent years,which will continue to affect the change of water quantity in future years.While the existing water resources allocation program does not consider the dynamic quantity changes of water supply.Therefore,aiming at these two aspects and based on the existing allocation program and research development trend,the impact of varying conditions and rainwater resources on water supply of Dalian is studied in this paper.The main contents and results are as follows:(1)Based on the result of water resources allocation scheme from planning of sustainable utilization of water resources in Dalian(2011~2030),the problems in the scheme are analyzed from the impact of varying conditions on water resources quantity and water supply structure.(2)Aiming at the problem that the existing scheme does not consider rainwater utilization,the utilization of rainwater resources in Dalian is studied.First,using rural areas in Dalian as the key research objects and Xiaoying village as the typical region,rainwater utilization measures are chosen according to the characteristics of different water users in typical region.Second,based on the law of water balance,different design volumes of rainwater collecting facilities are calculated as well as cost and benefit.Third,reasonable project and rainwater utilization goal is selected according to the results from step two.Finally,total amount of rainwater resources which can be used is evaluated based on the result of typical area.(3)Aiming at the problem that the existing scheme does not consider the possible dynamic change in water resource in future years,the predication of changing trend of water resource in Dalian is studied in the paper.Using LARS-WG as the downscaling method,CNCM3 、HADCM3 and IPCM4 are selected out from 15 GCMs in the IPCC Fourth Assessment Report based on the performance in simulating precipitation and temperature in Biliuhe Reservoir basin.Future changes of precipitation and temperature are evaluated under A2,A1 B and B1 scenarios,while future change of runoff is evaluated by using ABCD model,the results of which can help provide the basis for water resources planning and management.(4)Based on the results of rainwater resources utilization in Dalian and the predication of dynamic change of water resources,water supply and demand balance is re-analyzed under A2,A1 B,B1 scenarios.Then measures are proposed from the aspects of water conservation,water transfer to ensure the security of water supply in 2030.