Study on evolution of ecosystem health of Dongting Lake wetland

By taking Dongting Lake Wetland as the researched region,the model of decision tree classifi cation was set up and was used to extract the distribution regions with different features in Dongting Lake Wetland based on Landsat remotely sensed images. According to the pressure,state and response model,taking into account the features in Dongting Lake Wetland,the evaluation indicators of the system were chosen,thus the Dongting Lake wetland ecosystem health assessment model was established. Further,the evolution situations of ecosystem health of Dongting Lake wetland in six periods from 1987 to 2013 were analyzed by adopting GIS technology. The results show that the ecosystem health of Dongting Lake Wetland was in a downward trend before 2003 and after that the health state rose again gradually,and there was a time lag between outside pressure and wetland health state.