Analysis of the land landscape changes and its driving mechanism in vulnerable ecological area: a case study of Yulin city
生态脆弱区土地利用格局变化及其驱动机制分析 ——以陕西榆林市为例

In this study we quantified land landscape change in the vulnerable ecological area of Yulin city between 1985 and 2000 using remote sensing and GIS in conjunction with landscape modeling. It was found that fallow land decreased by 125,147 hm2 while grassland and woodland increased by 107,975 and 17,157 hm2, respectively. The three most prominent changes were from fallow land to grassland at 129,926 hm2, and degradation of grassland from a higher cover density to a lower one at 16,996 hm2 , and from grassland to woodland at 15,651 hm2. The major factors responsible for these changes are identified as the change in the government policy on preserving the environment, continued growth in mining, and urbanization. It is concluded that as arid Yulin city has a highly vulnerable landscape that is sensitive to fluctuations in the natural environment and to changes in government land use policy. The efforts in restoring the deteriorated ecosystem have reaped certain benefits in reducing the spatial extent of sandy land through replacement by non-irrigated farmland, woodland and grassland. On the other hand, continued growth in mining and urbanization has exerted adverse impacts on the land landscape. At present regional economic development is in direct conflict with the protection of the natural environment. Such a conflict has caused the destruction to the land resources and fragmentation of the landscape accompanied by land desertification, even seriously in some localities.