Research On Water Environment Carrying Capacity And Control Scheme Of The Typical Lake

The water environment carrying capacity was one of the connotation of sustainable development.It was the fundamental way to solve the problem of water environment that the economic development is optimized,water environmental carrying capacity was reasonably regulated.It is important meaning to evaluate the water environment carrying capacity of the important regions and establish the pointed plans for the water pollution control that guide the regional sustainable development of social-economy. Based on he concept and application examples of water environment carrying capacity in Home and abroad,the water environmental carrying capacity was defined for the westside of Hongze lake.its definition.The bear pressure of the water environmental carrying capacity was maximum.that was dependent on the carrying the sustainable social and economic development of the region continuously, and satisfying integrality of ecological function of oneself.Taking the water environment in the westside of Hongze lake as a typical case, the relationship between the pollution characteristics and eutrophication and water quality factors was studied through monitoring data of the comprehensive analysis in the westside of Hongze lake. The important problem of water environment was screened. In view of the ecological environment characteristics in the west lakeside of Hongze lake, and taking population, economy, resources and environment composite system as the study object,the evaluation index system of water environmental carrying capacity was constructed. System dynamics model of water environment carrying capacity and the evaluation model bases on the weight of the factor analysis were established in order to evaluate the state of water environment carrying capacity and analyze the existing problems and main control factors in the westide of Hongze lake. According to the pointed scenarios of social and economic development,the water environment carrying capacity was predicted,the dynamic changes was evaluated,and the way of coordinated development between the water environment and social economy was investigated.The management strategies and suggests were put forward to improve the water environment which can provide the scientific proof for realizing the benign development between the regional society-economical development and water protection.The main contents and research results are as follows:1. Simple factor assessment and comprehensive index were used to assess the current status of water environment. The results showed that, The water quality was be the level of medium-eutrophication and worse in the westside of Hongze lake.The trend of water quality decreased from Ⅳ to Ⅴ,and was be the worse level of heavy pollution for the past few years.78percent of sampling stations were not satisfied with the demand of the water functional zones for2015. High concentrations of nitrogen, phosphorus and more suitable ratio of nitrogen and phosphorus was the material conditions of Algae growth.But the automerism of the sediment state and the algae state is unfavourable for the growth of algae that resulted in the concentration of chlorophyll-a did not reached the eutrophication level.2.The water environmental capacity of TN and TP were computed by the OECD model in the westside of Hongze lake. The water environmental capacity of COD and TP ammonia nitrogen were estimated by the lake largest amount of pollutant of the sewage outfall in the flow river. Based on the water quality requirements and the aim of water quality, The water environmental capacity of COD and ammonia nitrogen were calculated in the westside of Hongze lake.The control target of the total pollutants amount based on water environmental capacity and information entropy was explored. The value of water environmental capacity of COD and ammonia nitrogen were189169.3ton and9458.47ton Respectively,the value of TN and TP were19421.27ton and971.06ton in the normal flow year.The reduced rate of the COD,TN and TP emission loads need to reach100%,101.88%and98.15%in order to meet the requirements of water environment capacity.3. On the basis of the principle of system dynamics, according to compound system including resources, environment, economy in the study area,the evaluation index system was built on pressure(Population, social economy, environment pollution and resource utilization) and support force(Water resources,water environment capacity and social resources allocation) that were based on population, socioeconomic, environmental pollution, resource utilization, environmental capacity,allocating social funds. The valuation model of water environment carrying capacity was built based on the index weights were determined by the factor analysis that could reflect the single index and their t rules of the temporal and spatial variation.4. Water environment carrying capacity of the westside of Hongze lake was comprehensively evaluated based on the valuation model. The results showed that, in recent years,the current status of WCC was "overload".The great pressure of social and economic development and the slow development speed of support capacity including water-resource,ecology system and the allocation of social resources were the major cause of the overload of water environment carrying capacity in the west side of Hongze lake.The principal limiting factors of water environment carrying capacity were the compliance rate of functional area, eutrophication state and the rate of water resources and demand in westside of Hongze lake.The water environment carrying capacity was difficult to improve effectively in the short term because the development of regional economy was still in a stage of rapid development.5. According to the regional social development goals and the pressure and the influence force index that constrained carrying capacity of the west lakeside of Hongze Lake, the two scenarios of the present situation and development situation were set up. Scenarios analysis showed that the water environment carrying capacity was going to be all right in the westside of Hongze lake during recent ten years. Scenario I represents ecosystem changes under the present module,whereas scenario Ⅱ reflects ecosystem changes under improved development.The results show that, the carrying status will significantly be improved under two scenarios compared with the period of2004to2009in the next10years.Under scenario Ⅱ,the carrying status of water environment in the westside of Hongze lake will be improved gradually,which turn into over-loaded from loaded.Under scenario Ⅰ,the carrying status will be over-loading all along. T he scenarios analysis indicated that all of the following measurement, such as adjustment of industrial structure, pollutant total amount control, Increase the proportion of the tertiary industry, increasing investment environmental protection to reduce the amount of COD and wastewater discharge Per unit GDP,saving water, could improve the water environment carrying capacity of the westside of Hongze lake.6. In recent years, economy development speed were faster than that of the water environment deteriorates,the relationship between water environment and economy is disharmonious.Attention greatly attached to economic development than environmental protection will lead to the unbalance relationship between economy and environment,and The coordinated development of economy and environment is hard to achieve.Regulation scheme of simulation results show, a win-win road for economic development and environmental protection is the fundamental guarantee that chieve the goal of the coordinated development between economy and environment.The scientific management target, reducing the pressure,increasing the support force were the main ways to improve WECC of the westside of Hongze lake.In view of the complexity of the water environmental system,the study of water environmental capacity and total polltant control was a long-term and very hard work. This paper had made some achievements,because of the limited knowledge of author,some problems of cognition,analysis,research is not perfect,and need further study.