The Healthy Assessment Of Wetland Ecosystem In East Dongting Lake

Wetland is one of the most important ecosystem on the earth, it makes great effects on regulating climate, conserving water resources, normalizing flood, accelerating silt's building land, purifying environment and protecting the biodiversity. However, as the development of the industrialization, the acceleration of the urbanization and the irrational human activities for the unilateral seek of economic growth, the wetland resources have been excessive exploited and utilized, which lead to the reduction of the quantity and quality of the wetland, even lead to the recession of it's function on ecological service and it's biodiversity. Since the 1900', fifty-percent of the natural wetlands have disappear. The important significance and the large pressure that the wetland has to face gradually enhance the human's consciousness of protecting wetland. As the task of wetland protection being promoted thoroughly, the core task of wetland will be transformed from wetland protection to wetland management. As the healthy assessment of the wetland ecosystem is the basis of the wetland management, researching the way and method of the healthy assessment of the wetland ecosystem can provide technical support in order to make us run the task of wetland management and restoration better in hence. The dissertation regard the east Dongting Lake wetland natural reserve as the research object, which is one of our country's first array of the international important wetland, establish the index system and assessment model for healthy assessment of wetland ecosystem in east Dongting Lake, evaluate the healthy condition of wetland ecosystem in east Dongting Lake by the method of BP neural network, analyze the major trend of it's ecosystem's healthy condition, finally propose a series of countermeasure and step to promote it's healthy condition. Major result to the research show as follow:(1) Conclude the characteristics and function of east Dongting Lake. It is the biggest natural and seasonal lake of east Dongting Lake at present with best protection, It's diversity, systematicness and property is precious in the world, with it's special water and wetland environment, it has produced a plentiful of resources such as aquatic, plant and birds, besides, it's also abundent in sandrock and travel resources.(2) By analyzing it's characteristic and function and combining the principle of the index filtering of healthy assessment of wetland ecosystem, we establish the index system of healthy assessment of wetland ecosystem in east Dongting Lake through three aspect of the wetland ecosystem such as pressure, state and response which is based on the PSR model, then we filter the index through brainstroming method and in and out of the meeting method. We consult the national and international standard on the wetland healthy assessment and sort the score from the high to the little in order to reflect the healthy alteration from good to bad, then we divide the healthy condition into five levels,they are so healthy, relevant healthy, normal healthy, normal sick and morbid.(3) It comes over the influence made by artificial factor in determining the weight of the assessment index by using the method of BP neural network in building the healthy assessment model of wetland ecosystem in east Dongting Lake, which makes the assessment more objective and scientific. The results show that the healthy conditions of wetland ecosystem in east Dongting Lake from 2005 to 2009 are respectively normal sick, normal healthy, normal sick, normal healthy, normal healthy out of healthy level.(4) The result also shows that the healthy condition of wetland ecosystem in east Dongting Lake is in better trend, but the integral healthy level is low. Therefore, we must set up the correct consciousness in resource utilization to build and perfect the model of community co-management, and we should also control the plane source pollution strictly and implement a series of laws and regulations relevant to the wetland protection actively in order to promote the healthy level of wetland ecosystem in east Dongting Lake and give full play to it's ecological service function on regulating flood and maintaining biodiversity.