| Using Rs and GIS, Hefei Landsat TM imagery of 1989, 1995, 2003 and 2007, the paper analyzed the land use change and landscape configuration change, the study area covers 716km2 of 4 urban districts. Using Fragstats3.3 the paper analyzed the feature and layout change of urban forest. And also the driving force of the layout change was summarized from the aspect of population, policies, and economics and so on. The results were as follows:(1) The land type was divided into six categories: the farmland, the building and pavement area, urban forest, general green land, water and the bare land. The results indicated that: The farmland and urban forest decreased 20790.36 hm2 and 486.18hm2 respectively in the period of 1989-2007; 73.27 and 7.7 percent of the studied area was distinguished as farmland and urban forest land in 1989, but both of them decreased to 44.3% and 7.03% respectively in 2007, the annual change rate is 2.19% for farmland and 0.49% for urban forest land. The other land categories had an increase trend in generally. The building and pavement area increased 19404.9hm2 in 2007 compared with that in 1989, whose proportion of total area decreased from 11.98% to 39.01%, and its annual change rate reached 12.7%. The general green land increased 450.9hm2 in this period, and its annual change rate is 14.6%. The bare land and water increased with fluctuation. In summarized, in the period of 18 years the land use change of Hefei urban district was mainly transformed in farmland, building and pavement, and urban forest.(2) During 1989 to 2007, the number of landscape patch and the edge density increased, indicating that the landscape pattern was more complex. The shape index increased significantly, indicating both of the shape of patch and the landscape edge was more irregular and complex. The landscape fractal dimension had little change, indicating the shape of landscape element patch in Hefei had not changed too much. The landscape diversity index was increased, indicating the diversity level of landscape in studied area of Hefei was improved. The landscape fragmentation index had an increasing trend, indicating urban forest pattern became dispersed because of distribution from human activity.(3) During 1989 to 2007, the number of urban forest patch, the patch density, the patch size index, and the edge density increased, indicating that the size of urban forest patch was more irregular and complex. The shape index increased, indicating the shape of urban forest patch was more irregular and complex. The urban forest patch shape feature of three periods is different: During 1989 to 1995, the shape index increased from 59.2238 to 103.0047, which indicated that the shape of urban forest patch had a great change; During 1995 to 2003, the shape index increased from 103.0047 to 107.4157;During 2003 to 2007, the shape index decreased form 107.4157 to 109.3692, the change of which is mild. The fractal dimension index is increased from 1989 to 2003, which indicated that the shape of urban forest patch was more irregular and complex. But after 2003, the fractal dimension index decreased from 1.4595 to 1.2873,which indicated that in recent years some big urban forest patches were founded and the complication became decreased. During the 18 years, the patch density increased and the aggregated index decreased from 90.7309 to 77.6591, indicating urban forest pattern became dispersed and distributed by human beings. The change of patch density was fierce during 1989 to 1995, while the other two periods changed mildly.(4) Analyzing Hefei Statistical Yearbook, the urban land use is closely related to the increase of population, the development of economics, and the driving force of policies. During 1989 to 2007, the farmland and urban forest were decreased, while the building and pavement area was increased, which had direct relationship with the increase of population, the development of economics, and the driving force of policies. |
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