Study On Ecological Security Pattern Of Erhai Lake Basin

With the acceleration of urbanization and industrialization in China,the contradiction between man and the natural environment is worsening and resulted in ecological damage caused by habitat destruction,biodiversity reduction and serious degradation of land carrying capacity,which seriously threaten regional ecological security.Therefore,it is an important way to realize regional sustainable development and environment protection by constructing regional ecological security pattern to improve the ecological security situation.Based on the Erhai Lake basin,this paper analyzed the dynamic changes and driving forces of the landscape pattern from 1995 to 2015 and evaluated the ecological security status of three time points and the trend by PSR model.The ecological red line area was defined by the method of biodiversity conservation and water conservation importance evaluation.Based on the results of the division,the minimum resistance model was used to construct the ecological security pattern of Erhai Lake basin,which provided scientific basis for regional landscape pattern optimization and ecological security management planning.The main conclusions are as follows:(1)The landscape pattern of Erhai Lake basin has changed from 1995 to 2015,and there was a tendency of fragmentation and diversity.The connectivity between the landscapes deteriorated and landscape pattern has decentralized development trend.(2)The ecological security index of Erhai Lake basin was 42.51,41.55 and 41.59.The critical ecosystem was in the critical safety level and the overall ecosystem was degraded in 20 years.(3)The total area of ecological red line in Erhai Lake is 1274.36km2,accounting for 49.01%of the total area of the study area.(4)According to the ecological red line area division results identify the source and based on the theory of land ecological suitability evaluation,the buffer area of Erhai Lake basin was divided into three levels:high,medium and low,with an area of 359.88km2,294.9km2,493.81km2,accounting for 13.84%,11.34%and 18.99%of the total area of the study area.According to the hydrological analysis method,47 ecological corridors and 14 ecological nodes were extracted,and the ecological security pattern of Erhai Lake basin based on "ecological source-buffer zone-ecological corridor-ecological node" was constructed.Compared with other studies,this paper constructed the ecological security pattern by defining the ecological red line to identify the ecological source and it can solve the ecological problems of important ecological function areas,sensitive areas and fragile areas in the region,and then built a more comprehensive and systematic ecological security pattern.