Study On Current Situation And Changes Of River Sealine Landscape In Guangzhou

The landscape changes of the river sealine not only affect the hydrological processes of the valley,but also affect the energy transmission , the elements flow and the species flow .Because the principles of landscape ecology is applicable to the structure and the ecosystem process analysis of the river sealine landscape very much,so the research of this aspect is an important realm of the principles of landscape ecology,and is also a hot research of the landscape ecology.In this paper, the remote sensing images of Guangzhou in 1979,1990,2000 and 2006 were used. Mosaic ,subset and other preparation were used to handle the remote sensing images,and single-band threshold method, the relationship between spectrum, vegetation index and water index method were used to extract the the water of Guangzhou city, and a buffer analysis was done at last. On this basis,the satellite images covering the study region were classified using a supervised classification method ,with the help of land cover map, the landcape maps of four periods in study area were got at last.The landscape pattern indexes were used to analyse the landscape pattern ,the dynamic changement of landscape.The conclusion is as follows:1. Employing single-band threshold method, the relationship between spectrum, vegetation index and water index ,the main river water of Guangzhou City was extracted from TM image of Guangzhou.At last, water index was considered to be the most suitable one after comparative analysis.2. The big patches are the main body of the structure of the river sealine landscape of Guangzhou, and other smaller patches gathered surrounding the central part .Therefore, a landscape pattern was formed such as: farmland, urban inhabitant land and other land is the main body, with forest land, orchard land, water and unused land gathered surrounding them.3. With the expansion of the buffer zone, the proportion of the water, urban inhabitant land and other land reduced,but the proportion of the farmland, forest land,orchard land and unused land increased,all above instruct that human activities play a significant role in the formation of the river sealine landscape pattern. 4. As the expansion of the buffer zone,the diversity index,the evenness index and the fragmentation index increased with the decreased of the development and utilization of the land by human,but the dominance index reduced.Close to the river sealine more,the human activities are more violent.5. From 1979 to 2006, the economy in Guangzhou gets a fast development,the population increases quickly, the farmland decreases sharply ,the water also decreases but the degree is small; urban inhabitant land and other land expands rapidly, close to the river sealine more, the greater the degree of swelling;the unused land was constantly exploited,the area drastically reduced;the orchard land area increased, and more away from the river sealine, the greater the increase.As such a development,the urban ecological landscape of Guangzhou city will be deteriorated, reducing or repressing the continued development of this kind of process is the important content of river sealine landscape for ecological construct in Guangzhou City from now on.6. By analysing the landscape pattern index for study area from 1979 to 2006 nearly 30years,it is found that the fragmentation index increased,the fractal dimension reduced,the diversity index reduced and the dominance index increased. With the progress of mankind and the development of science and technology, the interference ability of mankind with nature growing stronger and stronger,so the fragmentation of the landscape gradually deepened; the fractal dimension reduced and a simple geometric shape indicated that the human interference degree increased; the diversity index reduced and the dominance index increased is due to the people's programming sorting and effectively intensive exploitation with farmland, urban Inhabitant land and other land,making these two kinds of landuse types distribute concentrated more and more ,and occupy a bigger advantage position within the scope of the whole research area. This kind of pattern is not conducive to the sustainable development of the region.