Gradient analysis of urban green space landscape pattern in Shenyang City based on QuickBird image

Based on the urban green space distribution map interpreted by 2006 QuickBird image of Shenyang and under the support of GIS,5 km was taken as the appropriate spatial extent for urban landscape pattern analysis based on the effects of spatial extent,and the gradient analysis in combination with landscape metrics was made to study the landscape structure and its spatial characters along the transect of urban green space in Shenyang City.The results showed that at class level,different types of urban green space across this transect had obvious gradient characters.The dominant landscape type in urban center was public park,while that in rural region was agricultural land.The urban green space had high fragmentation,and patch shape was complex.At landscape level,the landscape metrics along this transect had different variation patterns.It was suggested that urbanization induced landscape fragmentation and heterogeneity.The patch density,landscape shape index,and landscape aggregation index had significant gradient characteristics,while the largest patch index and Shannon's diversity index were in adverse.It was also suggested that gradient analysis in combination with landscape metrics would be a robust tool to study the spatial pattern of urban green space.