大中流域水土保持宏观分区方法的探讨

The Discussion of Macrozoning Method for Water and Soil Erosion in Large and Medium Size Watersheds

根据乌裕尔河流域地貌型态，土壤侵蚀的演变过程，确定了宏观分区因素。通过量算分析得出，从河口至河源随海拔高程的递增，主河道比降、河流分支比例呈递增趋势，人口密度呈递减趋势和土壤侵蚀广度中游大、上下游相对小的规律。以这４个因素为依据，采用定点分段判别的方法将乌裕尔河流域分为３个宏观控制区。

In this paper,the factors for macrozoning of water and soil erosion are allocated on the basis of the geomorphologic features and the developing procedure of soil erosion in the Wuyur river watershed,and from the quantitative calculation result,the soil erosion pattern that the soil erosion intensity is larger in the middle reach of the river than that in the upper and lower reaches of the river with the increase of ground elevation and the gradient of main course,and the decrease of population along the river from the mouth to the original source of the river having been found out.Based on such 4 factors,the wuyur watershed is divided into 3 macro controlling zones by adopting the method of positioning section.