Dongtai Weikenou Mudflat Wetland Ecological Security Evaluation And Its Ecosystem Service Value Analysis

The beach wetland is not only an important land reserve resource for the economic development of Dongtai, but also provides powerful ecological service function and resources environmental value. Nevertheless, series of changes evolving the environment of beach wetland in Dongtai have taken place in recent years, due to the natural processes and high strength of human activities, i.e. wind power projects, reclamation project et. al, serious challenges are imposed on the resources exploitation and protection of beach wetland. However, the key question for salt and water environment management in reclaimed areas is to investigate the beach wetland changes, therefore, it is of much significance to optimize the model of land utilization and realize the farmland efficient and sustainable usage practically.A beach wetland located in Dongtai in Jiangsu province is chosen as the study area in this thesis, with the help of RS, GIS technologies methods and SPSS software, the data of land usage is obtained by translating the three phase remote sensing image data in1984,2001and2011. Based on landscape pattern changes of the specific research area caused by land usage in the past27years over1984-2011, evaluation on the ecological security situation tamper with the wetlands dynamically and analysis on the value changes in the Dongtai coastal wetland ecosystem have been conducted. It is desired to offer the fundamental data and policy-making evidence for the sustainable development and environment protection of wetland resources in Dongtai. The results shows that:①As compared with the reclaimed areas in Dongtai in1984, the plant area of Spartina alterniflora L. and Suaeda glauca Bunge had been reduced by4,359.67hm2and2,467.99hm2respectively in2001, but on the contrary, the area of aquacutural ponds and crops had been considerably increased, they had been increased by1,881.94hm2and11,596.97hm2respectively;②From2001to2011, the area of aquacutural ponds had been dramatically increased due to the exploitation of the beach wetland in the past ten years, it had reached11,313.90hm2with a net increase of9,128.66hm2;③The ecological security index of the reclaimed areas in Dongtai was3.242in1984, and droped to0.279in2001, but further decreased to-3.521in2011, the ecological security level decreased year-by-year, more importantly, the trend of decline was accelerating. When analyzing the subsystem level of the ecological security, it could be found that the state indicator was the key factor affecting the ecological security, the deterioration of state indicator was closely related with the decline of driving force, pressure and response indicators;④The variation of ecosystem services value of various vegetation types was inconsistent with each other over the range of1984-2011, but in general it all appeared to rise, it had been increased by137,762,900RMB.