Long-term dynamics of cultivated land resources and their driving forces of Guyuan City in upper reaches of Jinghe River

The land use patterns in Guyuan City, Ningxia Hui Autonomous Region of China, have changed greatly over the years, due to population growth and fanning and stock raising development. This study, using 50-year statistical data of cultivated land and 14-year spatial data of land use pattern, analyzed the developmental stages, the character, and the spatial variance of farmland in the city, and discussed the driving forces of cultivated land changes based on empirical and conceptual statistical models. First, the change of cultivated land area went through different stages of rapid increase, fluctuating change, decrease and rapid decrease from 1949 to 2004, additionally, social and economic policies in different stages had an important impact on farmland variance. Second, from 1986 to 2000, the quantity of cultivated land increased, but its quality decreased. Third, social and economic factors are determinant factors in cultivated land transition. Five constructed paths explain cultivated land transition. Factors that have direct or indirect effects on farmland include the economy (X-eco), the population (X-pop), agricultural output (X-agr), and scientific input (X-sci). The sequence of impact was X-eco>X-pop>X-sci>X-agr. Among all these impacts, X-eco was the major positive one, and X-pop was the major negative one. It is urgent to take measures or adopt a policy to stop the vicious cycle in eco-environment and agriculture production. Otherwise, negative patterns of farmland use will increase, and high-quality cultivated land will continue to decline