三峡库区腹地乡村聚落空间分布特征及其土壤侵蚀分析--以奉节的27个乡镇为例

Analysis of the Spatial Distribution Character and its Soil Erosion of Rural Settlement in the Center Region of the Three Gorges Reservoir Area——A Case Study of 27 Towns of Fengjie County

以三峡库区腹地奉节县的27个乡镇为研究区,运用景观生态学理论、地理信息系统和统计分析方法,借助Erdas8.5、ArcGIS 9.3以及Fragstats 3.3软件,探讨三峡库区腹地奉节县27个乡镇乡村聚落空间格局特征及其土壤侵蚀。结果表明：①研究区聚落分布整体较为分散,且斑块面积较小,但从局部上看,聚落空间分布呈现出北部＂总体分布密、面积大＂,南部＂总体分布稀、局部密集,面积小＂,聚落密度高低值相差达9倍以上的分布特征;②聚落的平均最邻近距离、平均斑块面积在不同岩性上差异小,而在不同地貌类型上差异大;③聚落斑块随高程和坡度变化分布差异明显,海拔1 000 m以下及坡度15-25°的区域,聚落斑块分布比例最大;④聚落对其周围环境产生的土壤侵蚀主要表现在：聚落分布多的地区,土壤侵蚀较严重,相反,聚落分布少的区域,侵蚀较微弱;不同聚落缓冲区内的不同土壤侵蚀等级面积差异显著,且随着距聚落距离的增大,同一等级强度的土壤侵蚀面积呈明显的下降趋势。

Taking 27 towns of Fengjie County of the center region of the Three Gorges Reservoir Area as a case, this article analyzed the essential characteristic of spatial distribution of rural settlement and soil erosion based on some means of the theory of landscape ecology, （;1S, statistical analysis technique and some softwares, such as ErdasS. 5, ArcC-ISg. 3, Fragstats3. 3. The results of the research showed that： （a） The spatial distribution of rural settlements of 27 towns in Fengjie County is extremely scattered and its area is small. From the local of view, the spatial distribution of rural settlements shows such patterns： the distribution is thick, size is large, in the north, however, the grown form of distribution is discrete, the distribution of local area is thick, and size is small, in the south. The density＇s differences of settlements differ over 900%. （b） The MNN-MN and MPS of rural settlements present minuscule differences on the different ideologies, but present biggish differences on different landforms. （c） The difference of distribution of settlement plaques is obvious for various elevations and slopes, the range of elevation about below 1000m and slope 15--25° is the intensive settlement distrihution area. （d） The soil erosiono[ the settlement on the surrounding environment is pres cnted that： the more settlement distribution, the more serious soil erosion, on the contrary, the less settlement distribution, the more weak soil erosion; the different degrees soil erosion area in different settlement buffer are significantly different, and with the increasing distance from the settlement, the same level of intensity of soil erosion area showed a significant downward trend.