| The land is the carrier of economic activities for human beings; the use of land is the mode and intensity of producing materials; and the dynamic changes of the land use reflect the trend of the land use mode.This paper makes use of the TM images of Sanheyuan in 1996 and 2006 and obtains the data of using land with the aid of Remote Sensing & GIS technology. Firstly, the writer analyzed the characteristics of land use condition; secondly, the writer discussed dynamic changing rules of land use in this area; thirdly, analyzed the factors which effect the change of land use in general. The results of this research are as follows:1) Seen from the area and variation amplitude of land use type, from 1999 to 2006,during the same period, the reduced rate of the bare land is the biggest in total of 12.38 kilometers, the amplitude was 11.78%.2) Seen from the speed and trend of the type of land use type, the sequence of the area change in one year Rs was the cultivated land, next is the water area and contribution land of town; it is consistent with the above point; moreover, the fastest in reduced rate was the rare land. The cultivated land was the fast one in the rate of changing in the Rss. The low-covered grassland was also changed faster which get to 1.38%. Each type of land has the consistent direction in changing.3) Analyzing from the transfer of different land type, the low-covered grassland increased mostly which increased 299.14kilometers from 1999 to 2006. The water area also increased much which increased 96.56 kilometers. The transferring matrix of land use type showed that the unchangeable land type was much more than the changeable land type. The general trend of land use transfer is that the rare land and barren lands turned into low-covered grassland and the woodland and swamp turned into high-covered grassland. The transfer of land types influence by the human beings activity and the change of natural environment, especially the cultivated land, the water area and the contribution land have close relationship with human beings activity and the development of community. As the participation of human beings, there exists hidden problem in the change of land use type. In the recent years, the sand land,Gobi and woodland showed the trend of expansion. As to the reduced land types, the most obvious is barren lands;The swamp and woodland are next to it.4) The climate, landform and soil and so on affect the change of land use in Sanheyuan. This area gathers the area which rainfall is less than 400mm; the main activity there is animal husbandry. In the recent 8 years, the change of land types place between 200mm to 400mm, moreover, it is bias on the northwest of rainfall line. It is because this area is affected by human beings activity much and it is also the combining area of agriculture and animal husbandry,so the most obvious changing land are the grassland, unused land, woodland and cultivated land. The main changeable area is the source of river where human being activity is intensive. The factors of human being contain urbanization and industrialization, the lead of policy,the change of population and the development of economics. The change of land use is the result of the function of natural and socio-economic factors together. Moreover,the change of temperature and precipitation affect the change of grassland and unused land directly; besides, the state's policies,population and socio-economic development together impact the change of land use way. |
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