Study On Ecological Assessment At Shuangtai Estuary Wetland Of Panjin

Wetland as the unique natural complexes is formed by the interaction between earth surface and waters; it is an extremely important and irreplaceable ecological system, which is listed as the three global ecosystems together with forests, oceans. In recent years, the effect on global warming, population growth and the pressures of economic rapid development, it also led to unnormal evolution of wetland ecological, causing the ecological system structural imbalance or functional imbalance, the wetland area decreased greatly, the degradation of the function, and it is in a serious position. Wetland protection has become a global task. To establish an effective framework is very important to wetland protection mechanism and system, it also has very important significance for sustainable development of wetland and society and economy.PanJin ShuangTai estuary wetland as the national nature reservation is located in LiaoNing province, which is listed as "the territory of international important wetland nature reservation", located in shuangtai estuary, the top of BoHai LiaoNing bay, is the world’s largest reed marshes and the national nature reservation in China. In recent years.PanJin ShuangTai estuary wetland began to appear the degeneration phenomenon, in order to save the wetland, protect the precious natural resources, this paper studies the status of the wetland taking the sustainable development as the basic guiding thought.This paper analyzes from the wetland existence, formation, based on the research results which were fully absorbed, summarizing the research advancement of various evaluation methods, studies on wetland vulnerability, water environmental health and function representation, it provides the basic theory for further the treatment of wetland environment management work.1. Based on the PSR model, this paper established the evaluation index system, it also did the understanding of translation during the years of 1995 and 2007 in ShuangTai estuary wetland by using the remote sensing technique comprehensively, which completed the macro survey of the wetland resources situation, retained the foundation data of ShuangTai estuary wetland the results shows that the area of paddy field increased by 1000 hm2 during the 12 years, the area of natural reed decreased about 5000 hm2, the area of aquaculture ponds added about 5000 hm2,these data displayed and expressed that the USES of some natural wetland are quietly changing. It established the wetland ecological vulnerability evaluation mathematical model by using the factor and multiple factors model, it also did the vulnerability evaluation combining with the landscape ecology, wetland vulnerability and other basic theory during the process of evaluation.The results shows that the ecological vulnerability belongs to potentially vulnerable (0—0.2) in research area, the natural state of landscape has begun to show signs of recession, the function level also exists the possibility of degradation, restoring force of outside interference also begins to appear the signs of deterioration. Overall wetland ecological system natural landscape still keeps a good state, structures are complete, energy level remains basically normal, restoring capacity is stronger.2. Collecting the basic materials, based on the principles of function evaluation and evaluation system establishing, this paper does the descriptive assessment of shuangtai estuary wetland function, and mechanism analysis of the substance formed and pollution purification of wetland, the research result of the material production shows that and irrigation water depth is the effect of main factors that influence the growth of reeds. From the experimental results,we know that the irrigation water level depth has positive effects on the yield, the study found that the reed appropriate depth range should be from 20cm to 25cm. Keep the irrigation mode of the water during the depth range from 20cm to 25cm can achieve the purpose of increasing water saving.Pollution purification research result shows that the content of heavy metal has a close relationship with the growth of wetland plants, with the reproductive growth of plant, the heavy metal content basicly presents:the change process with higher—reduce—rise, the periods of the largest amount of increasing and reduction respectively appear in:May to June and June to August. Through comparing the changes of the heavy metal contents in the water andsoil, it found that the heavy metal contents in the soil declines basicly higher than in the water, it also showed the wetland plants absorb the heavy metal mainly by the root.This paper does the quantized comprehensive evaluation to the wetland function with the method of quantification analytic hierarchy process. Evaluation results show that the comprehensive function index of shuangtai estuary wetland is 0.4323; the comprehensive function belongs to general category. Wetland has played a crucial role in habitat, pollution purification, substance formed and adjusting the floods, it also has played an important role in regulating climate, scientific research and education, historical and cultural heritage and breeding function, compared with the aesthetic value and entertainment function, it is not very prominent.3. Adopting the matter-element analysis method and fuzzy comprehensive evaluation method, this paper does the comprehensive evaluation of water quality in ShuangTai estuary wetland, the results shows that:in outfall area, the evaluation results of matter-element extension method and the fuzzy mathematics method are basically the same, while in core area and infall area, the results of assessment are only one grade. Comprehensive comparison of the evaluation results with two kinds of methods, it shows that during flood period and frozen period, the water quality in core area and outfall area is better than infall area; during non-flood period, the water quality in core area is better than outfall area and infall area. The water quality is not optimistic, water levels are already exceeded the level of national nature reservation, water qualityⅠ, the best state of water environment quality just belongs to water qualityⅡ, the worst water quality has been in class V.The research methods and results in this paper have important theoretical significance and practical value for realizing the sustainable development of wetland ecological environment, this paper provides method and means for finding out the reasonable utilization of wetland resources, curbing wetland degradation and keeping wetland ecological environment from being destroyed.