Spatial Differentiation of Arable Cultivated Land in China

Based on spatial analysis methods of GIS,the terrain elevation and gradient classification maps were produced by using digital terrain elevation map.And then,the terrain distribution data of the cultivated land of counties of 2000 was extracted and arable cultivated land area of counties of 2006 was calculated,by overlapping the terrain elevation classification map,terrain gradient classification map,cultivated land distribution map of 2000 and administrative division map of counties.Taking arable cultivated land index and per capita arable cultivated land area as indicators,the spatial differentiation of arable cultivated land in China was analyzed.As a result,this paper found:1) The terrain distribution characteristic of cultivated land in China was that the cultivated land area descends sharply with the increment of terrain elevation and gradient.Cultivated land was mainly distributed in the region where the altitude was below 500 meters and the slope gradient was under 3°.2) The spatial differentiation of arable cultivated land was mainly controlled by terrain condition.The arable cultivated land index usually exceeded 50% in plain,basin and river valley where the altitude was relatively low and the hypsography was mild.But the index value was generally below 30% in those plateau,mountainous land and hilly-gully regions where the altitude was relatively high and the hypsography was complicated.3) The whole characteristic of spatial distribution of per capita arable cultivated land area in China was that the value of the north of China was more than the south,the types of Higher and High where the per capita arable cultivated land area was above 0.2 hm2 mainly concentrated in the north of China,and the types of Lowest and Lower where the per capita arable cultivated land area was below 0.067 hm2 mostly located in the Qinghai-Tibet Plateau and the southeast coastal areas of China.