Analysis on dynamic change of land use in Shaanxi Province
陕西省土地利用动态变化分析

Based on detailed survey data of land use from early 1991 to late 2001, using models such as synthetic dynamic degree model,conversion rate model, new increase rate model, synthetic index model and synthetic index change model of land use, this paper analyzed great changes in land use in Shaanxi Province during this period of time.Figures indicated that 119.40×10 4hm 2 of farmland, 2.21×10 4hm 2of garden land,7.64×10 4hm 2 of forest land,21.02×10 4hm 2 of grassland,1.52×10 4hm 2 of rural residential land and city and town land,0.13×10 4hm 2 of traffic land,1.07×10 4hm 2 of waters and 14.85×10 4hm 2 of unused land changed to other types of land. Meanwhile, 10.44×10 4hm 2 of farmland, 45.47×10 4hm 2 of garden land, 59.79×10 4hm 2 of forest land, 29.28×10 4hm 2 of grassland, 9.65×10 4hm 2 of rural residential land and city and town land, 2.66×10 4hm 2 of traffic land, 2.36×10 4hm 2 of waters,and 8.19×10 4hm 2 of unused land were converted from other types of land. The synthetic dynamic degree of land use in Shaanxi is 0.726%·a -1. The covertsion rate of farmland is 1.885%·a -1, the biggest number among conversion rates of other land use types.Synthetic index of land use degree in Shaanxi is 2.301 in 1991, and 2.282 in 2001. The conclusions are drawn as follows: (1)Land use changed greatly in Shaanxi Province from 1991 through to 2001. Garden land changed most greatly, with cultivated land, traffic land, residential and urban land, and grassland also witnessing greater changes. (2)Land use in Yangling was most active and in Hanzhong was least active. The overall relative change rate of land use in Yan'an was high, because Yan'an emphasized the adjustment of industrial structure, put the policy of returning cultivated land to forest and grass into effect, and improved the infrastructure construction such as traffic conditions during the last 11 years. (3)Urban, rural residential and traffic land uses increased quickly, which indicates that under the situation of the West China development, the traffic conditions were improved and the urbanization steps quickened constantly in Shaanxi. (4)The land use degree in Yangling was the biggest. The one in Shangluo was the least. The land use degree in Weinan, Xi'an and Yangling increased during the last 11 years, and the land use degree in other regions decreased. (5) The cultivated land returning to forest and grass mainly happened in south and north of Shaanxi and agricultural structure adjustment mainly in the middle of Shaanxi.(6) The driving factors of land use change in Shaanxi are natural factor, policy factor, economic adjustment and population factors.