基于GIS的商南县土地利用地形分布特征研究

Research on Topographic Distribution Features of Land Use of Shangnan County Based on GIS

为了揭示商南县土地利用的地形分布特征,利用地理信息系统的空间分析技术,通过对商南县土地利用现状图和数字高程模型提取出的地形要素图的叠加,得到不同土地利用类型在坡度、坡向、高程、起伏度等方面的分布状况,在此基础上,利用吉布斯-马丁多样化指数公式计算出不同地形因子下的土地利用类型多样化指数。结果表明,商南县的土地利用类型以林地和牧草地为主,其次为耕地,其它土地利用类型所占比例较小。耕地、居民点及工矿用地、交通用地和水域集中在朝东、朝南坡向。园地、居民点及工矿用地和水域主要分布在较低高程和起伏度较缓地块,耕地、牧草地和交通用地主要分布在中度高程和起伏度中等地块,林地和未利用地主要分布在较高高程和起伏度较大地块。土地利用类型多样化指数随坡度的增大、高程的上升和起伏度的增大而显著下降。

In order to reveal the topographic distribution features of land use of Shangnan County,the space analysis technology of geographic information system is used to obtain the distribution conditions in the different types of land use in the slope degrees,slope directions,elevations and rolling degrees via the existing map of land use in Shangnan County and the overlap of topographic element maps extracted from the digital elevation model.Gibbs-Mirtin diversified index formula is used to compute the diversified indexes of land use types in the case of different factors.The results indicate that the land use types in Shangnan County are the forest land and grassland in the main;the cultivated land is next;and the rest of other land use type accounts for very small percentage.The cultivated land,resident point and industrial and mine land use,communication land use and water area are concentrated in the slop lands facing the east and south.The garden land,resident point and industrial and mine land use and water area are mainly distributed in lower elevations and the slop lands with less rolling degrees.The cultivated land,grassland,and communication land use are mainly distributed in the pieces of land with medium elevations and medium rolling degrees.The forest land use and uncultivated land are mainly distributed in the large piece of land with higher elevations and higher rolling degrees.Accordingly,the diversified land use indexes drop remarkably with an increase in slop degrees and a rise in elevation and an increase in rolling degrees.