ANALYSIS ON THE CLASSIFICATION OF SLOPING CULTIVATED LAND AND ITS BASIC CHARACTERISTICS IN THE NORTHEAST MOUNTAIN REGION OF YUNNAN PROVINCE

From the point of studying soil erosion and rational utilization of sloping cultivated land in mountain region, the paper puts forward the concept of sloping cultivated land in general sense, sets up the classification system of sloping cultivated land. According to this system and the data of land use status investigation, the paper gains the amount of every sloping cultivated land type in the northeast mountain region of Yunnan provice. Using six indexes, this paper analyses the basic characteristics of sloping cultivated land in this region. The main conclusions are: 1. The sloping cultivated land in general sense is defined as all cultivated land in the slope of 2°. 2. The classification system of sloping cultivated land is the following: Contour__cultivated landterraced paddy fieldterraced irrigated paddy field wait_to_rainfall paddy field terraced landterraced irrigated land terraced non_irrigated land vegetable land Slope_cultivated landslope non_irrigated land rotation_fallowed land 3. In the northeast mountain region of Yunnan provice, the distribution of sloping cultivated land is very broad, and its area is very large, the value of sloping cultivated land index (I) has arrived at 94.52%. Slope_cultivated land area occupied an advantage in all sloping cultivated land, the value of slope_cultivated land index (I S) has arrived at 87.87%, and contour_cultivated land index (I C) was only 12.13%. Moreover, the topographic slope of sloping cultivated land is big, the area of steep cultivated land in the slope of 25° (I SS ) has occupied 17.71% in total sploping cultivated land area, and the index of slope of 6° and 15° (I S6 and I C15 ) arrived at 78.97% and 90.74% respectively. This is the concrete embodiment of exploiting intemperately land and destroying long_standingly forestry, also the main causes for the serious soil erosion in this region.