Study on Quantitative Variation of Cultivated Land and the Driving Forces in Yunnan Province

Based on the method of time series,model of cultivated land dynamic degree and method of statistics,the driving forces and the reasons of variation about the quantity of the cultivated land from 1997 to 2005 in Yunnan Province were analyzed.The result indicated that the variation of dry land on all types of cultivated land was the most obvious,the area of total quantity and per capita of the cultivated land increasingly descended.In addition,the increase in population and economy,and the driving forces of non-agricultural construction,ecological restoration,natural disaster,agricultural restructure,land exploitation,land reclamation and land consolidation had an influence on the variation of cultivated land.The ecological restoration was a dominant driving force of the land loss,but the land exploitation was the most importance of land increase.