SPATIO-TEMPORAL DYNAMICS OF COASTAL WETLAND LANDSCAPE PATTERNS IN YANCHENG, JIANGSU PROVINCE

Abstract

Using the land-use dynamic degree model,conversion matrix and landscape pattern indexes obtained by the RS and GIS,the authors quantitatively analyzed the dynamic process of the coastal wetland landscape pattern in Yancheng city during the past 15 years(from 1992 to 2007).Some conclusions have been reached:(1) Owing to the development of coastal economic and the increasing requirement for land resources,the area proportion of natural landscape in Yancheng coastal zone decreased by 12.63%,while the proportion of man-made landscape rose continuously.(2) The area of original natural landscape types was reduced by 763.62 km2 totally,the number of patches decreased,the total edge shrank,the shape of the patches tended to become more irregular,the preservation ratio became lower,the massive original natural landscape types were converted to the artificial landscape types,and hence the wildlife's habitat decreased badly.During the same period,the area of Spartina alterniflora was expanded,resulting from the initial introduction of 144.92 km2 by 2007,which occupied a large area of tidal flats between the Sheyang river and the Liangduo river in Yancheng coastal zone.(3) The dominant conversion processes indicate that the human reclamation of coastal wetland was enhanced,and the effect of human activities on the change of local environment was also intensified gradually.The achievements in this study can provide scientific basis for the sustainable utilization of land resources and the protection of coastal wetland resources in Yancheng.