Abstract:

In order to provide valuable ecological benefits to urban ecosystems and properly design plan and use the wetland in Changsha, spatial statistics (geostatistics) was employed in analyzing the changes of size and distribution of wetlands during the 1955-2007. The results showed that: (1) from 1955 to 2007, human activities played a key role in spatial-temporal change of wetland of Changsha. All wetlands ring distributed around the city of Changsha. The wetland area was increased firstly and then decreased. (2) The area of ponds and ditches were increased significantly from 1955 to 1990, however, were substantially decreased from1990 to 2007. The area of lake and reservoir was fluctuated, it decreased ceaselessly from 1955 to 1972, and increased from 1972 to 1990, then decreased from1990 to 2007.The change of the area of river was small. River was more stable. (3) In the four period, according to Moran's I index, Moran scattered point diagram, the distribution of the ponds was concentrated, the distribution of the river was dispersed, the distribution the lakes and canals was random. And in 1970, 1990 and 2007, the distribution of the ponds was high value formed by the aggregation of spatial autocorrelation. Furthermore, the distribution of a lot of ponds presented positive local spatial autocorrelation in each period. In summary, an examination of changes in wetland size and distribution was useful in wetland management, especially in urban and fast-growth regions. Locations where wetland losses were occurring most frequently could be identified, as well as the types of wetlands most frequently destroyed and the predominant causes of loss. This information, in conjunction with information on projected population increased, could be used to help resource managers and regulators anticipate where increased demands on wetlands were likely to occur. These areas could then be targeted for protection prior to urbanization and the consequent wetland destruction.