土地利用演替与冲沟、山地自然灾害发展趋势分析

AN ANALYSIS OF THE TREND OF THE SUCCESSION OF LAND-USE AND THE DEVELOPMENT OF GULLIES AND NATURAL DISASTERS

通过对小流域的土地利用演替、冲沟发育、山地自然灾害等的动态趋势分析,指出土地利用——冲沟类型和强度——山地自然灾害三者间有一定的量化关系,可建立一套以冲沟发育为主线索的区域土地垦殖临界系统,为山地灾害防治与预测开辟新途径。并表述了笼统以25°坡度作为上地垦殖或耕地退耕的“指标”是值得商确的观点。

By analyzing the trend of the succession of land-use and the development of gullies and natural disasters in a small basin this paper indicates a certain quantitative relationship among land-use, gully's type and intensity, and natural disasters in the mountains. Tn order to open a new way for precautions against disasters in the mountains a critacal system of regional land cultivation focusing on gully's development must be set up. The author also expresses her different point of view on the idea that the surface slope of roughly 25° may be regarded as an index for land cultivation or for its stoppage, and thinks the 'index' should be further discussed.