Study On Ecosystem Health Assessment Of Dianchi Lake Basin Based On Land Use And Landscape Pattern Change

The Dianchi Lake Basin has important ecological,social and economic benefits,but it is now facing problems that are difficult to balance between ecosystem health and regional coordinated development.This not only seriously threatens the ecosystem health of the Dianchi Lake Basin,but also contributes to the sustainable development of human beings.Therefore,the evaluation of ecosystem health in the Dianchi Lake Basin is conducive to promoting the change of land use landscape pattern and the update and development of the theory and application of watershed ecosystem health in terms of theoretical guidance.It is conducive to the comprehensive development and management of the basin in practical sense.And the sustainable development of the basin.This thesis takes the Dianchi Lake Basin as the research object,and takes the ecosystem health theory as the theoretical basis.The 2010,2015 and 2017 global land cover datasets FROM-GLC are the main data sources,and the land use degree comprehensive index model and land are adopted.Using the model of type transfer matrix and landscape pattern index,the data of land use/cover change and landscape pattern index were extracted,and the land use/cover change and landscape pattern change in Dianchi Lake Basin were analyzed and selected as indicators.17 evaluation indicators were constructed to construct the Dianchi Lake Basin ecosystem health evaluation index system based on the PSR model.After the standardized value,the analytic hierarchy process was used to assign weights to each evaluation index,respectively,for the Dianchi Basin 2010 and 2015.Quantitative description of the ecosystem health status of the year and 2017,analysis and discussion of the evaluation results,and propose corresponding countermeasures and recommendations.The main conclusions of this thesis are as follows:(1)The area of agricultural land,forest land,water body and wetland,and other land used in the study area decreased by 457.85km~2,22.39km~2,38.04km~2,and54.35km~2,respectively.The area of grassland and construction land increased by248.89km~2 and 323.32km~2 respectively.The highest degree of dynamics is grassland,reaching 15.75%,followed by construction land,which is 13.79%.The comprehensive index of land use degree has been increasing from 2.49 to 2.58,and the land transfer type area has the largest amount of agricultural land,of which274.88km~2 is transferred.Into the construction land,209.83km~2 was transferred to grassland.(2)Since 2010 to 2017,the landscape fragmentation index of Dianchi Lake Basin has increased from 0.44 to 0.59,the average patch area has decreased from2.29km~2 to 1.70km~2,and the fractal dimension of the perimeter area has increased from 1.56 to 1.63.From 63.75 to 56.66,the shape of the plaque is more and more complicated and scattered,and the degree of fragmentation is increasing.(3)According to the classification scale of ecosystem health assessment,CEI=57.59 in 2010,CEI=58.17 in 2015,and ecosystem health value between 40 and60,indicating that the ecological health status of Dianchi Lake Basin is Grade 3,which is generally healthy.In 2017,CEI=62.64 in the Dianchi Lake Basin,the ecosystem health value is between 60 and 80,that is,the health status of the Dianchi Lake Basin ecosystem has risen to level 2,which is a healthy state.In response to the actual situation of ecosystem health in Dianchi Lake Basin,policy recommendations are proposed:relevant departments timely establish ecosystem health including ecosystem health management system,ecosystem health assessment and prediction system,ecosystem health decision support system and ecosystem health policy supporting system.