Analysis of the dynamic change and spatial difference of cultivated land pressure in Gansu Province

The changing features of cultivated land area were analyzed based on 64-a statistical yearbooks,the minimum per capital cultivated land area and pressure index of cultivated land in Gansu Province were calculated,and the tendency of pressure index of cultivated land in the future 15 years was estimated using the GM( 1,1)model. The results showthat cultivated land had increased 1. 67 × 104hm~2,the minimum per capital cultivated land had reduced 0. 526 hm~2,and the pressure index of cultivated land had reduced 0. 951. It is found that the pressure index of cultivated land has difference among the 14 prefecture: lower than the warning line( k = 1) in the most of the Hexi Corridor,east and south of the province,higher in the central sub-region of the province,highest in Gannan Autonomous Prefecture. It is estimated that pressure index of cultivated land will decrease slowly in the future 15 years,showing a serious cultivated land pressure.