Study Of Water Resources Carrying Capacity Based On System Dynamics Model In Tieling City

Based on the relationship between sustainable development and bearing capacity, through summarizing the literatures home and abroad, the definition of water resources bearing capacity was given and intensive analyses on the connotation, characters and influential factors of water resources bearing capacity were conducted in this paper.On the basis of understanding the conception of water resources bearing capacity and the theory of sustainable development, the study regarded the situation of the utilization of water resources in Tieling city in the year of 2004 and the basic data of the water environment as the starting point and combined the bearing capacity of water resources with the sustainable development. From the population, economic, social, environment and resource perspective, the study investigated the level of water supply and demand and the situation of the water environment in Tieling city, analyzed the interrelationship of the factors intensively, and established the system dynamics model of water resources bearing capacity of Tieling city. By the computer simulation model, the trend of the society and economy, the water supply and demand and the pollution of the water environment from the year of 2010 to 2020 can be observed. Meanwhile, 14 core variables were collected from the model as the evaluation index of water resources bearing capacity. To analyze the trend of the bearing capacity, the values gained from the model were managed, and the bearing capacity in the following 10 years was computed.The result indicated that in accordance with the status of the present development program the water resources bearing capacity of Tieling city declines every year in general. By 2020, supply and demand of water balance will be as high as 11.42 billion cubic meters, and industrial wastewater will reach 12727.3 million tones. The situation of the water resource and environment cannot support the long-term development of Tieling city. In short, the present social and economic development of Tieling city has no sustainability.In view of the existing situation, three optimized programs (economic development scheme, water-saving and sewage treatment scheme and comprehensive development scheme) were proposed to solve the declining bearing capacity. Then, the programs were compared and the optimum one was determined. Compared with the existing development program, although the GDP of industry would reduce by 5.77% till 2020, the volume of industrial wastewater discharged, the COD emissions of point source, non-point source and the total COD emissions would reduce by 53.29%, 9.8%, 20.56% and 17.78%, respectively. To a large extent the non-point sources were controlled, which would effectively control the water environment of Tieling city and largely enhance the water resources bearing capacity of Tieling city. Finally, for the optimal development program, effective measures were suggested to improve the water resources bearing capacity of Tieling city.