Study On Land-Use/Cover Change Of Liang-zi Lake Area Based On Remote Sensing Technique

The RS conception and current trend using RS inside and outside of the country were simply introduced. The general natural and social situation was illuminated. The TM types and the theories and methods to judge the types were introduced.It gave a detailed introduction about the classification process of Liang-zi Lake land use supported by Erdas Imagine 8.5 software with the resource of LandsatTM of 1987, 2000 and 2004. The total classification accuracy was 88% for 2004, 86% for both 1987 and 2000 respectively; Then used mathematic method to analyze the change of land use, and it was found that all the land use types changed to some degree, but the amount and degree of change was different obviously. Based on the analysis of land use, the area of arable land and orchard land decreased in first land grade, and others showed increasing trend. In the second land grade the area of water land, dry land and paddy land decreased, and others seemed to increase. To analyze from the change of land use, the area of arable land changed greatly with decreasing of 4787.3 hm~2 in 17 years. Second is water area , which is 3341.92 hm~2 , residential area increased with 1229.24 hm~2 , however the change of orchard land, grass land and forestland was not obvious. Analyzing from the degree of change, orchard land changed greatly with 27.92% in first land grade, then is the residential land with 26.94%, other showed limited change. In the second grade the area of pond changed greatly with 42.44%, then is the paddy land with 26.29%, and others changed little. To analyze from the yearly change of land use, the residential land changed mostly with 1.91% and then is orchard land with 1.28% from 1987 to 2000; from 2000-2004 orchard land changed mostly with 3.38% and then is water area with 1.90%; from 1987 to 2004 orchard land changed mostly with 1.64% and then is residential land with 1.58%.The change of land-use was analyzed qualitatively and the reason for the change of orchard land, arable land, residential area, traffic and water area was analyzed detailedly. The result showed that from 1987 to 2004 the main reason for the change of land-use types was the great economic development in the investigated area, the change of population configuration, the increasing of people consuming, the increasing of travel industry and the complication of market economy. The study indicated that the land-use changed in some degree in the area, although the main land -use type did not change, but the arable land decreased yearly, and residential area and traffic area increased, which is the main reason to restrict the continuing use of land.Totally, because of the change of land-use types, the biodiversity was threatened in the area, and this was disadvantaged for the natural economic system.