基于遥感与GIS的黄土丘陵半干旱区土地利用定量化研究-以中国定西县为例

研究区域为典型的黄土丘陵沟壑半干旱区,以中国定西县为例。从1990年和2000年的Landsat TM影像图中提取两个时段的土地利用图,包括9种土地利用类型。从1∶10万的等高线数据中提取坡度数据。参考景观生态指标,我们选择或修改了10个指标实现定量化土地利用特征,动态监测土地利用变化,并分析地形与土地利用和土地利用变化的关系及土地利用变化与政府政策之间的关系。结果表明:①所选择的指标可以量化中国典型的黄土丘陵半干旱区土地利用及其变化特征,当转移矩阵采用不同的基数,可以体现不同的转换的量的特征;②土地利用与土地利用变化在不同坡度的空间分布上有很好的规律性;③政府政策是土地利用变化的主要驱动力因素,包括梯田改造、集雨工程和退耕还林还草。

Study on the Quantifying Land-use in Loess Hilly Semi-arid Region Based on Remote Sensing and GIS-A Case of Dingxi County, China

The study area of this paper is Dingxi County, a typical loess gully\|hilly region of the semi\|arid regions. The land use maps in 1990 and 2000 were compiled from the Landsat TM images and other data resources. There are 9 kinds of land use types. The slope data derived of contour lines. Referring to some metrics of the landscape ecology, 10 metrics were selected or developed for quantifying the land use characteristic, monitoring the land use changes and analyzing the relationships between land use, land use changes and the topographical condition, governmental policies of the Dingxi County. Some conclusions were obtained. The selected metrics can quantify the land use and land use change in typical loess gully\|hilly region, Dingxi County. The land use and land use change have good spatial distribution regularities in the slope grades. The governmental policies are the primary driving factors for the land use changes in our study area. The policies are reclaiming the slope farmlands and grassland into terraces, rainfall\|collection works, and reforesting and regressing some sloping cultivated lands.