Research On The Assessment And The Carrying Capacity Of Water Resources In Chang-Ji Economic Circle

The Chang Ji economic circle,including Changchun and Jilin,is the political and economic center of Jilin province.The spatial distribution of water resources in the area is quite different,and some areas are facing a certain shortage of water.Facing the actual conditions such as water quality deterioration,water shortage and overexploitation,the water resources in the area must be analyzed to determine the capacity of water resources in the study area,and to determine the development scale of the future cities according to the situation of water resources,and provide the basis for the government to make decisions.The water environment capacity is used as a part of the evaluation index of water resources carrying capacity,and the water resources carrying capacity of the study area is analyzed and calculated with the dual indexes of water and water quality.This paper gives full consideration to the effect of water quality on water resources carrying capacity,and puts forward different water use schemes and suggestions according to the recent and long-term national economic development plan and the calculation results of water resources carrying capacity.The main results are as follows:(1)Evaluation of water resources:using frequency analysis to calculate the falling water of different guarantee rates,using the Tyson polygon method to determine the surface precipitation,combined with hydrological station data,runoff modulus and runoff depth contour,the runoff coefficient method is used to calculate the amount of surface water resources,according to the boundary line of the flow field,the lithology of aquifers and the water rich and so on.The research area is subdivided into 29 calculation sections.The amount of groundwater resources in the plain area and mountain area is calculated by the equilibrium method and the straight line slant method.The annual surface water resources of the study area are19.05×10~8m~3,the groundwater resources are 9.865×10~8m~3 and the total water resources are 26.40×10~8m~3.(2)Analysis of supply and demand balance:analyzing the annual supply,water demand and development trend of the current level,using the method of grey correlation analysis and multiple linear regression model,the supply and demand water demand of different planning levels is predicted and the supply and demand balance analysis is carried out,and the water shortage appears in the current level of Changchun urban area.There is no shortage of water in the Changji economic circle in 2020 and 2030.(3)Water quality evaluation:the improved Nemero index method was used to evaluate the water quality of surface water,and the water environment capacity was calculated by the zero dimension model of the overall standard calculation method on the basis of water function zoning.The results showed that the water quality of the surface water in the area was not good,the water quality of the river was not equal to the class II to V type water,and the ammonia nitrogen and COD water environment capacity was small in the area.The protection and control of surface water should be strengthened;groundwater quality is evaluated by adding annotation scoring method.The groundwater quality is dominated by class II water.Type III water distribution is mainly distributed in the northern part of Jilin city and Shuangyang district.Type IV water is mostly distributed in Changchun urban area,Jiutai,Yongji county and Jilin section of Songhua River.Types I and V are distributed in a scattered manner.(4)Water resources carrying capacity:combining water and water quality,the water environment capacity is taken as part of the evaluation index of water resources carrying capacity,and the mathematical concept model and evaluation system of water resources carrying capacity are set up in accordance with the sustainable development of society and economy.The fuzzy comprehensive evaluation method is used to analyze and evaluate the water resources,and 4 of them are put forward.The water resources carrying capacity of the study area is analyzed by the water use prediction scheme.The water resources carrying capacity of the district is moderate,and the water resources carrying capacity of Chaoyang District is the least.The water resources carrying capacity is maintained at the middle level by the plan two planning,while the project three considers the water saving project and the water resource carrying capacity is in the middle.The water resources carrying capacity of some areas in Jilin is better.In scheme four,the water resources carrying capacity of the whole region is obviously improved,the water resources carrying capacity of the whole region is generally better,and the water resources can support the rapid development of the social economy.Through comprehensive analysis using the project four as a recommendation,it can be seen that taking advantage of the transit water resources is conducive to the rapid development of the Changji economic circle.