Health Evaluation of a Lake Wetland Ecosystem Based on the TOPSIS Method

Wetlands, sea, and forest are the three most important ecosystems on our planet. Considering the rapid degradation rate of wetlands, health evaluation of wetlands has become one of the hot points in the research field of wetlands. In this research, health and the pressure-state-response model of ecosystem was used as the tool, data was collected with remote sensing technology, field investigation and social statistics were used as the basis, and a health evaluation index system for Poyang Lake Wetland was created, which was composed of a pressure subsystem, a state subsystem, and a response subsystem with an established evaluation criteria. The values of weight of the subsystems were determined through the analytic hierarchy process (AHP), which were then introduced into the TOPSIS model for calculation. Furthermore, the index values were compared with the ideal values and the grade criteria, through which health conditions of Poyang Lake Wetland were evaluated and the limiting factors of wetland health were determined. Through the comparison between the approach degree of ideal alternatives in 2008-13 and that of 5 evaluation grade and ideal alternatives, the health states in 2008-13 were finally determined as: sub-healthy, sub-healthy, sub-healthy, sub-healthy, subhealthy, sub-healthy. Finally, countermeasures for the ecological restoration and protection of the wetland were put forward.