| The Yangtze River Delta,located in the southeast coast of China,is one of the famous estuarine deltas in China and the world.In the past 20 years,the Yangtze River Delta region in the city's industrialization and rapid development process,the social economy made great progress at the same time,with the rapid expansion of city construction land also occupy a lot of farmland and ecological land,exacerbated the degree of habitat fragmentation,resulting in a series of ecological and environmental problems,land the dramatic changes in the profound influence on the regional ecosystem health and ecological security.The negative effects of land use/cover change and urban expansion have seriously threatened the ecological environment of Yangtze River Delta,and become the main obstacle for regional sustainable development.In the background of sustainable development,regional ecosystem health has attracted more and more attention,research on ecosystem health assessment although there have been considerable development,but because of the nature of the health indicators to reflect the characteristics and ecological system will be insufficient due to its limited.Land use and land cover change of ecosystem structure and ecosystem function(Health),and from the land use and land cover change reflect from the perspective of the construction of ecosystem health,elastic force and vigor index,is a possible approach to regional ecosystem health evaluation method,which can not only reflect the characteristics of regional ecosystem health also,convenience,availability and real-time updates the index,drivers can also directly reflect the regional ecosystem health change.The study on land use change is the most severe in the Yangtze River Delta as an example,based on the dynamic change of land use and landscape area transfer matrix and the analysis of landscape pattern index and habitat quality on the construction of ecosystem health assessment,including elastic organization and dynamic model of regional ecosystem health theory based on the the ecological system of flexible choice of habitat quality index mainly reflects the habitat patches of different land use threat source resistance stability;ecosystem organization by spatial heterogeneity and landscape connectivity to decide,Shannon diversity index,the spread of the 6 landscape pattern index to characterize the ecosystem;activity to vegetation coverage index characterization.The main conclusions of this paper are as follows:(1)The Yangtze River delta takes cultivated land as the main land use type,and the area of construction land has increased significantly in 1995-2015 years,and the total area of water and forest land has decreased because of the reclamation of farmland and deforestation.During the 1995-2005 years,the area of the forest land in the Yangtze River Delta turned out to be large,which was mainly transformed into the landscape of cultivated land;in the 2005-2015 years it turned out to be large and turned into cultivated land and construction land.The change of construction land is the main feature of land use change in the Yangtze River Delta.In 20 years,the percentage of construction land area has increased by 101.44%,and the area is increased to 9376.44 km2.(2)The Yangtze River Delta of the land 20 years dynamic habitat quality change was analyzed by using the dynamic change of In VEST and habitat quality model based on the analysis results show that the Yangtze River Delta regional habitat degradation degree increasing,the overall decline in habitat quality is obvious,the landscape fragmentation degree and rise.But the local area,especially a large area of woodland and water landscape is to maintain a high index of habitat quality,landscape patches around the present environmental quality was decreased gradually,which is mainly due to the development of city land use/cover change makes intense woodland,water landscape surrounding areas transfer to non habitat the landscape,the threat factors enhance sensitivity,degree of habitat degradation due to intensified.(3)Over the past 20 years the overall health level of the ecological system in the Yangtze River Delta region showed a downward trend,the rapid city caused by land use/cover change in the Yangtze River Delta regional habitat landscape fragmentation increased,which is the main reason affecting the ecosystem health change,but the high degree of aggregation of forest and water landscape still can obtain higher regional ecosystem health this is because the value of forest land and water landscape has an important contribution to regional stability and habitat quality,dynamic resistance. |
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