Study On Ecosystem Integrity Evaluation Method In Fujian Delta Region

With the accelerated pace of economy in C hina,the dramatic changes in land use and cover caused by human activities undermined the integrity of the ecosystem,which has a far-reaching impact on the sustainable developme nt of the social,economic and ecological environment in the region.Fujian Delta Region is one of the most developed areas in C hina and Fujian province,which has entered the period of accelerating urbanization,but there are also the ecological environment problems of declining of ecosystem integrity.It is of great significance for the sustainable development of Fujian Delta Region to monitor and assess the the ecosystem integrity status.The paper assessd the ecosystem integrity of 2005,2010,2015 and 2017 in Fujian Delta Region based on the framework of the pressure-state-response(PSR)using a principal component analysis(PCA).The spatial heterogeneity characteristics of ecosystem integrity were analyzed by spatial autocorrelation analysis and semivariance analysis.The main contents and conclusions of this study are as follo w :(1)This paper analyzes the integrity of the ecosystem in the county as the evaluation unit,and in the 2005-2017 years,the degree of ecosystem integrity in each city and county of the Fujian Delta Region showed a decreasing trend.The county area with the maximum and minimum value of ecosystem Integrity index is located in Quanzhou,which indicated that the degree of ecosystem integrity varies greatly between cities and counties in Quanzhou,mainly because of the obvious difference of urbanization between cities and counties in Q uanzhou.The difference of ecosystem integrity between Xiamen and Zhangzhou cities and counties was small.From the change trend of time period,the change of ecosystem integrity in 2005-2017 was not much,which is mainly due to the saturation of the level of urbanization development in Xiamen after 2005,which indicated that the level of urbanization was the dominant factor to determine the change of its ecosystem integrity.For Quanzhou and Zhangzhou,in the 2005-2010 years,the coastal city and county(Shishi,Jinjiang,Quanzhou District,Zhangzhou District,Longhai)change degree;2010-2015,Zhangzhou,Q uanzhou C ity and county ecosystem Integrity degree change degree was not significant;There was also a marked downward trend during the 2015-2017,which was mainly influenced by the level of development of the region and the urbanization process.(2)Based on the results of spatial autocorrelation analysis and semi-variance analysis,this study considered that 600×600 m was a most suitable grain size to reduce the impact caused by the scale effect.The result of spatial autocorrelation analysis and semivariance analysis indicated that there was spatial correlation in the spatial distribution of ecosystem integrity.The distribution of ecosystem integrity with higher degree and lower degree were concentrated in inland regions and coastal regions,respectively.The values of nugget/still ratio,the sill,the nugget and the range showed a decreasing trend from 2005 to 2017.Based on the analysis of spatial clusters and spatiotemporal clusters,the results showed that the spatial distribution of ecosystem integrity was not random.In addition,a hole-effect semnvariogram was observed,which indicated that a high level of human intervention in Fujian Delta Region.During the study period,with the acceleration of urban expansion in Fujian Delta Region,the degree of ecosystem integrity was constantly decreased.