Research On Water Resources Carrying Capacity In Haidong City In Qinghai Province

Water resources are fundamental to social development. With the development of economy and the increase of population, water demand increases year by year. Water resources shortage has become one of the most prominent problems around the world. The overuse of water resources causes the problem that the limited water supply cannot satisfy the needs of social development. How to solve the contradiction between water resources and social population, economy and environmental development, and taking the path of sustainable, is very crucial in the field of current water resources research.Based on the concept of water resources carrying capacity and relevant theories, the paper analyzed the situation of water utilization in Haidong city, Qinghai province. And build the analysis index of water resources carrying capacity in Haidong city. The paper adopts the composite fuzzy evaluation model and the principal component analysis to analyze city water resources carrying capacity and its driving force. The system dynamics model is also used to simulate and forecast its supply and demand ability. The main contents and conclusions of this paper are as follows:(1)Based on the composite fuzzy evaluation model, the result from 2004-2011 shows that water resources carrying capacity of 2007 is affordable, but the rest of the years is critical.From 2012 to 2013, the situation of water resources carrying capacity turns better and the carrying capacity is affordable.(2) By using qualitative and quantitative analysis method, the paper apply the principal component analysis, considering natural and humanistic factors, to analyze the factors that affect water resources carrying capacity in Haidong city. As a result, economy,population, urbanization level, environmental protection and the degree of rational development and utilization of water resources are the main factors that influence the city water resources carrying capacity.(3)Using the system dynamics, this paper establish the model on the premise of water resources. According to scenario analysis method, the development and utilization of water resources, is designed respectively as trend scheme, water-saving scheme, pollution control scheme and comprehensive scheme. Results show that:( i) Under the trends scheme,namely on the premise of not taking any measures, only keeping population growing and thesocial economic development unchanged, the rest of the parameter values of the decision variables follow the trend of development. In 2019, the total water resources demand of Haidong city is 578 million cubic meters, total water supply411 million cubic meters, water supply balance 167 million cubic meters, and the water shortage degree is 0.29(value between0 and 1, the bigger the value is, the more serious water shortage is). By 2025, the total water resources demand is646 million cubic meters, total water supply 325 million cubic meters,water supply balance 321 million cubic meters, and the water shortage degree is 0.496.(ii)Under the water-saving scheme, in case of ensuring water for industry, agriculture and other industries as well as for life, by lowering the domestic water quota less than the planning value, some water-saving measures can be taken such as improving irrigation, adjusting the industrial structure, strengthening industrial water-saving and improving the technology of water-saving as well as improving the utilization ratio of water resources at the same time. In2019, the total water resources demand of Haidong city is 536 million cubic meters, total water supply410 million cubic meters, water supply balance 126 million cubic meters, and the water shortage degree is 0.235. By 2025, the total water resources demand is 566 million cubic meters, total water supply 325 million cubic meters, water supply balance 241 million cubic meters, and the water shortage degree is 0.425.( iii) Under the pollution control scheme, namely on the basis other trend scheme, increase sewage reuse level and give the initial value of sewage treatment ratio, sewage reuse rate respectively 60%, 30%. By 2020,sewage treatment ratio and sewage reuse rate will respectively reach 70% and 45%. By 2025,sewage treatment ratio and sewage reuse rate will respectively reach 80% and 60%. In 2019,the total water resources demand of Haidong city is 578 million cubic meters, total water supply422 million cubic meters, water supply and demand balance 156 million cubic meters,and the water shortage degree is 0.270. By 2025, the total water resources demand is 646 million cubic meters, total water supply 374 million cubic meters, water supply and demand balance 272 million cubic meters, and the water shortage degree is 0.421.