陕北农牧交错带土地利用变化及驱动机制分析

利用1986年、1993年及2003年3期Landsat TM遥感影像，借助遥感和GIS技术及回归分析方法，对陕北农牧交错带1986年～2003年土地利用变化及驱动机制进行了分析。结果表明，陕北农牧交错带土地利用综合程度总体较高，2003年达到36.5%，且土地利用正处于发展期；1986年～2003年土地利用变化以林地和建设用地大幅度增加和耕地、水域、未利用土地与沙地面积不断减少为主要特征。其中林地面积增加了44.18×10⁴hm²，主要由耕地、草地和未利用土地转化而来；建设用地面积以近0.27×10⁴hm²/年的速度增加，主要由耕地、草地、未利用土地和沙地转化而来；耕地面积减少了10.52×10⁴hm²，减少的面积主要转化为林地和草地；沙地面积减少了20.67×10⁴hm²。在空间上土地利用变化以南部和东南部黄土丘陵区沟壑区和毛乌素沙漠边缘地带最为明显。自然、人文和社会经济因素共同影响了土地利用变化，其中气候因素是驱动土地利用变化的重要自然因素，人口增长及社会投资的增加，工、农业产业化的发展直接驱动了土地利用变化。

Analysis of Land Use Changes and Driving Mechanisms in the Mixed Agriculture-Livestock Production Region in Northern Shaanxi

The driving forces of land use and land cover change (LUCC) are one of the main issues for LUCC research. LUCC is driven by both natural and socio-economic factors, but socio-economic factors have the most influence at local and short-term scales. In this paper, we analyze land use changes and their driving mechanisms in the context of a mixed agricultural and livestock production area in northern Shanxi Province. The study was based on Landsat TM images of 1986, 1993 and 2003 and methods from remote sensing, GIS and regression analysis. The results show that during the study period, comprehensive land use was relatively high, more than 36.5% in 2003. Land use declined from 1986 to 1993, while from 1993 to 2003, land use was in a phase of development and changes were drastic. The characteristics of land use change in the area included: woodland and built-up land area increased, while the total area of cultivated land, water bodies, unused land and sandy land consistently decreased. From 1986 to 2003, woodland area increased by 44.18×10⁴hm², mostly converted from grassland, unused land and cultivated land that was converted to woodland due to national policies on environmental restoration. These changes occurred in the southern loess hilly areas and in the sandy area in the northwest. With rapid economic development and growth of urban areas, built-up land increased at a rate of about 0.27×10⁴hm²/a, and was converted primarily from cultivated land, grassland, unused land and sand. The area of cultivated land decreased by 10.52×10⁴hm², and was chiefly converted into woodland and grassland. The area of sand decreased steadily, to 20.67×10⁴hm². In terms of spatial distribution, land use changes were most obvious in the south and southeast of the loess gully-hilly region and the Mu Us desert edge. Natural factors, human activities and socio-economic factors were the main drivers of land use change. We conclude that climate was an important component of natural factors that drove land use change, while population pressure, socio-economic activities and agricultural and industrial industrialization directly affected spatio-temporal shifts of LUCC.