摘要
地形因素是影响土地资源结构和变化的重要因素之一。以翁源县为例,在遥感与GIS技术支持下,采用改进的地形分布指数来分析粤北山区地形对耕地的分布与变化的影响。结果表明:耕地的空间分布与变化对地形十分敏感。研究区内,耕地分布频率最高的地形范围是坡度2°～4°和海拔0～200m。1993～2005年12a间,耕地面积增加了94.9km2。增加的耕地主要处在低海拔、缓坡区域(100～200m范围内耕地增量占总的耕地增加量的94.8%,0°～2°范围内耕地增量占总的耕地增加量的82.8%)。新增的耕地主要是作为后备耕地资源的林草地转化而来,耕地分布有向高海拔区域扩展的趋势。地形不但影响耕地的空间分布,还影响耕地的质量,并且海拔和坡度对耕地质量的影响机制也不同。改进的地形指数能更有效的描述和比较土地利用的空间分布及动态变化。
Topography is one of key factors that affect spatial structure and change of land resource. Basing on RS ＆ GIS technology, the effects of topography on distribution and change of farmland are analyzed in mountainous area of north Guangdong province using modified topography distribution index, a case study in Wengyuan County. The results indicate： Spatial distribution and change of farmland is sensitive to topography. In the study area, the distribution frequency of farmland locating in areas with elevation below 200 m or slope 2 -4 degree is highest. Farmland increased about 94. 9 km^2 from 1993 to 2005, and the increased farmland mostly locates in areas with low elevation or gentle slope （the percent are 94. 8% in 100 -200 m,and 82. 8% in 0 -2 degree）. Woodland and grassland used to be considered as reserved farmland resource transformed to farmland. There is a tread that farm- land was sprawling to the areas with higher elevation. Topography not only impacts on spatial distribution, but also the quality of farmland. Moreover, elevation and slope affect the quality of farmland in different ways. Modified to- pography distribution index is more effective to describe and compare spatial distribution and change of land use.
出处
《山地学报》
CSCD
北大核心
2008年第1期76-83,共8页
Mountain Research
基金
广东省自然科学基金项目(04201163,06105558)
广东省科技攻关项目(2005B30801004)~~
关键词
耕地
空间分布
地形分布指数
粤北山区
farmland
spatial distribution
topography distribution index
mountainous area of north Guangdongprovince
