Research On Safety Of Water Supply In Chang-Ji Economic Circle

The Changji economic circle is an economic community formed to improve the rapid economic development of the central area of jilin province with changchun and jilin city as the center.Due to the uneven spatial and temporal distribution of water resources in the study area,especially the extreme shortage of water resources in changchun city,and the existence of certain degree of water pollution in the area,the water supply safety evaluation of the study area is the premise to ensure the sustainable economic development and the normal life of the people in the area in the future.The evaluation results provide a scientific and theoretical basis for local governments to make decisions and management.To this end,this paper relies on the“Geological Environment Comprehensive Survey of Changji Economic Circle”project[121201007000150012]of the Shenyang Geological Survey of the China Geological Survey to evaluate and analyze the current situation and forecast of supply and demand water in the district.Taking the influence factors of water supply security into consideration,20indexes were selected from the 4 subsystems of water source-water supply engineering-water user-ecological environment to establish a complete set of evaluation index system for water supply security evaluation.The main results are as follows:(1)Comprehensive evaluation of water resources quantity and quality and analysis of supply and demand balance:Based on the research results of water resources calculation in the area completed by the predecessors,the Nemero index method is used to comprehensively evaluate and adopt the water quality of the area.The ration method analyzes the supply and demand in the district and the corresponding balance of supply and demand.It shows that the average annual surface and groundwater resources in the area are 19.15×10~8m~3 and 9.87×10~8m~3 respectively,and the total water resources amounted to 26.42×10~8m~3.The water is mainly composed of III~V water,and the groundwater is mainly II and IV water.Under the current conditions,there is water shortage in Changchun City in 2015,and there is no shortage of water in other areas.It is planned to reach 2020 and 2030.There is no shortage of water in the study area.(2)the construction of safety evaluation index system of water supply:considering the influence factors of water security and the correlation between different indicators,respectively from the water,water supply project,water user,and four subsystems of the ecological environment,the comprehensive and representative 20 indexes,create a set of complete index system of water supply safety.Entropy weight method and analytic hierarchy process are used to calculate the objective and subjective weights of each index,and finally determine the combined weight of each index.According to calculations,the top four weights in 2015 are annual precipitation,per capita water resources,centralized treatment rate of sewage,and the length of water supply pipeline for ten thousand people.By 2020,the top four are rainfall,water quality compliance rate,per capita water resources and surface water utilization rate.By 2030,the top four are rainfall,water performance,surface water utilization,and per capita water availability.(3)water supply safety evaluation:TOPSIS method is adopted to calculate the water supply safety of the index system established in 2015,2020 and 2030,and to obtain the safety schedule of the water supply system in the whole research area.In2015,the safety proximity degree of the whole water supply system was 0.52,which was in the critical safety state.The water source subsystem is in an unsafe state.Water supply engineering and ecological environment subsystem are in critical safety state.The user subsystem is in a safe state.In 2020,the safety paste schedule of the whole water supply system is 0.58,which is in the critical safety state;Water source and water supply engineering subsystem are in critical safety state.The water user and ecological environment subsystem are in a safe state.In 2030,the safety paste schedule of the whole water supply system is 0.63,in a safe state;Where the water source is in a critical safety state;Water supply engineering and water user subsystem are in a safe state;The ecological environment subsystem is in an ideal state of safety.(4)countermeasures and measures:according to the safety schedule results of the regional water supply system,corresponding safety countermeasures and protection measures are given from the perspectives of water source,water supply project,water user and ecological environment.In terms of water sources,qijia drinking reserve water source of changchun city and jilin emergency drinking underground water source of jilin city are built to provide emergency water sources of 2.87×10~4m~3/d and12.53×10~4m~3/d respectively.In terms of water supply projects,we will strengthen the security of water conservancy projects and make rational plans for water conservancy projects.In terms of water safety,we will optimize the industrial structure and formulate water-saving indicators.In terms of ecological environment,waste will be classified and treated,and incentive policies will be established to promote management with awards.