Urban fringe area ecological vulnerability space-time evolution research: the case of Ganjingzi District, Dalian

Based on the land use data of 1998 and the remote sensing data of 2003,2007,and 2013 SPOT5,the Ecological Vulnerability Index(EVI) value of the communities was calculated using the Exposure Susceptibility Coping Capacity(ESC) model combined with spatial analysis and linear weighting,and the ecological vulnerability of the Ganjingzi area was divided into five grades. To establish the evaluation index system,the change slope was calculated using the multiplication method. When the F value was significant,the change slope and significance were divided into four grades.Temporal distribution of ecological fragility in Ganjingzi District of Dalian,from 1998 to 2013,was also studied. The results were as folloes:(1) From the perspective of the distribution characteristics of ecological vulnerability in urban fringe areas,the ecological environment of the urban fringe area showed the same level of aggregation,and the neighborhood adjacent to the Shahekou District showed a distinct radial pattern,with obvious differences between the east and the west.(2) From theperspective of the ecological vulnerability of the communities,the ecological status of the communities within Ganjingzi District was significantly different. The ecological vulnerability of the communities adjacent to the urban area was remarkable,and the ecological environment was rapidly deteriorating. The mean EVI increased from 0. 62 to 0. 73. The change index,for significant differences,was 2.26. The ecological environments of some communities distant from the urban areas did not change remarkably,and were maintained in a good condition. In some communities,changes in EVI showed negative growth and the ecological environments gradually recovered.(3) From the urban fringe ecological vulnerability of the overall trend of change,the change of ecological vulnerability in Ganjingzi District between 1998 and 2013 was closely related to the speed of urbanization. With 2007 as the node,the average change or slope index in 1998-2007 was 0.51 and that in 2007-2013 was 0.19,showing a slow down after the first slow trend.