Research Of Carrying Capacity Of Water Ecological Based On The SD Model

In the process of rapid development of contemporary society, the contradictionbetween shortage of natural resources and increased demands become more prominent.The constraints of resources, environment and ecology on the research of socialdevelopment carrying capacity gradually have been developing. Currently, waterecological carrying capacity has been studied as a bridge for the developmentrelationship between human activities and water ecosystems. By studying the main lawof development and the responsive mechanism of the water ecological carrying capacitybetween subject and object, the extent and trends of coordinated development betweensocial economy and resource environment can be evaluated and predicted.Based on the basic theory of river basin water ecological carrying capacity of thefound, the Tieling control unit was analyzed as an example. The basic research mainlycomprises connotation and concept, features and characteristics, the principle, influencefactors and coupling relations of the ecological carrying capacity. Moreover，theapplication of system dynamics in the study of bearing capacity of water ecosystem aresummarized. The case study is aimed at the Tieling control unit carrying capacity ofwater ecological research by system dynamics simulation. According to the situation ofthe study area, the problem of water resources and water environmental bearingcapacity in the control unit was discussed, and some of the following solutions wereproposed. The main contributions include:(1) Water demand and the amount of COD into the river in the whole city wereselected as the main evaluation indexes. Calculated with historical data, during 2005-2012, the average water consumption of Tieling city accounted for48.7%of waterdemand, and the average COD discharge into the river accounted for266.7%of thewater environmental capacity. Comprehensive analysis of the Tieling water ecosystemproved that the main cavses for the negative influences on health were the largeamounts of pollutants being dumped into the river.(2) Based on the basic theory of the carrying capacity of water ecological and theactual condition of the Tieling water system, three objective functions are establishedfor evaluation overload. They are water bearing limit coefficient, the water environmentbearing limit coefficient and the water ecological comprehensive bearing limitcoefficient. The higher the bearing limit coefficient, the higher the bearing capacityoverload or limited degree showed.(3) This study considered water resources supply and demand and the waterenvironment carrying system as the main research focus. It established a systemdynamics model for the Tieling control unit. Through this study, a development trend ofthe water ecological bearing capacity was predicted. The results included: the limitingfactors of the water bearing capacity and the water environment bearing capacity thatwould be increasingly under stress.(4) Nine measures were recommended to improve the water ecological carryingcapacity optimization control scheme for the worsening situation of waters environmentsystem in the control unit. After the implementation of the nine program of measures toprotect aquatic ecosystems, water ecological comprehensive bearing limit coefficient bythe target year dropped from4.306to1.635(base year is1.701).It can ensure thesustainable development of population and economic stability In the target developmentsituation basically.