The Analysis On The Spatial-temporal Change Of Land Use/cover Of Dongjiang Source Region

It is well known that the study of LUCC has been one of the important foci.The technology of Remote Sensing(RS) and Geographic Information System(GIS) offers an effective and scientific tool for monitoring dynamic changes in land resources rapidly and accurately.In this paper,the utilization of RS and GIS techniques,3 remote-sensing images data of the research area,and the method that combined supervised classification and unsupervised classification technology were made use of acquiring the 3 land use/cover maps in 1986,1995 and 2005 and database of land-use changes from the year 1986 to 2005 in Dongjiang Source Region.We firldly analyzed the temporal and spatial characteristics from several aspects such as the quantitative change of land,the spatial change of land structure,change velocity,the transformation of land,and further explored the dynamic changes law of land-use during the last 20 years in the study area.Secondly,taking advantage of the principles/theiry of landscape ecology, we analyzed the landscape pattern of year 1986,1995,2005,further gave a brief introduction of the spatial and temporal changes of the region mentioned above.The principal conclusion is as follows:(1)During the two spans of time 1986-1995 and 1995-2005,most of the land classes not only had distinctly changed in quantity,even moving to the contrary direction,with the early augmentation and later reduction,or vice versa.Globally speaking,the area of other woodland,the arid land and the farmland was added by 19.45km2,11.90km1,8.79km2 respectively,however the region of the forestedland, the loosened woodland,the high coverage grassland decreased by 34.57km2, 5.56km2,3.13km2 separately.(2) From the point of view of conversion,most of the land pattern,to some degree, converted mutually.Of them,two types of cultivated land and four kinds of forest land converted not only frequently, but also greatly.There existed a few roll-out types:the area of the forestedland reduced by 61.16km2;the region of the other woodland decreased by 16.88 km2;the 16.31km2 area was reduced from the loosened land.There existed a few roll-in types:the 36.33km2 area of the other forest land was changed over from the other three kinds of woodland else;The forestedland accepted the 26.59 km2 area.The area of arid land and farmland increased by 17.63km2, 12.82km2 respectively.(3)In the course of research,the fragmentation of landscape and the shape of it had certainly changed.The shape of some landscapes was becoming more complex and irregular,that of others was getting more structured.But the richness density index had no change.The diversity index and evenness index of the landscape had augmented,indicating that the landscape was slowly toward the direction of diversification,with more heterogeneity,and all types of patches evolved toward the even distribution.At the same time the value of the dominance index of landscape was still 0.539 in 2005,showing that the landscape was subject to one or several dominant patch classes even if it was moving into the balanced development.