A RS/GIS-based Study of Changes in Land Use Patterns and their Fractal Analysis in the Pingtong River Watershed

By use of TM satellite photos in 1998 and 2006,as well as topographical maps,changes in land use patterns in the Pingtong River watershed were analyzed on the basis of Markov spatial probability model with support of RS/GIS software.Besides,the complexity and stability of land use were explored in terms of the dimensional theory.The results showed that prevalent changes happened in land use from 1988 to 2006 in the Pingtong River watershed.The proportions of farming land,forested land,bush land,grassland,water body,construction land and non-used land transformed respectively from 10.88%,57.62%,2.84%,1.58%,0.26%,1.30% and 1.525 in 1988 to 9.31%,59.13%,27.47%,1.72%,0.24%,1.38% and 0.74% in 2006.The complexity and stability change in fluctuating ways,the average dimensional values were 1.444 and 1.357 in 1998 and 2006 respectively;and the average stability indexes were 0.056 and 0.143 respectively.Within the second period,the average stability of land use type were as follows: grassland(0.233)water body(0.206) construction land(0.198) non-used land(0.175) bush land(0.143)forested land(0.138)farming land(0.042).Farming land,forested land and bush land were of poor stability,but there was no more changes for grassland and water body.The studies of land use pattern,complexity and stability could provide valuable reference for rational land use,spatial arrangement and structural optimization of protection forest systems in the watershed.