植被恢复过程与防止水土流失效果的研究

A STUDY ON THE RECOVERY PROCESS OF THE VEGETATION AND IT'S EFFECTS ON WATER AND SOIL CONSERVATION

本文通过多年调查观测的资料,论证了植物措施与保持水土的关系,植被覆盖度与实施植物水土保持措施的年限成正比的关系。植被结构的改良,植被覆盖度的增长,可以缩短地表径流过程,降低径流洪峰量,增加土壤入渗量,减少地表径流量。植被覆盖度与土壤面蚀成反比的关系。植被覆盖度小于60％时,土壤侵蚀量急剧上升,覆盖度增长到60％以上时,土壤侵蚀量明显减少,覆盖度增长到60％以上时,土壤侵蚀基本停止。

This artical is focused on the relationship between the effects of water and soil conservation and vegetation. The results are as follows:Ⅰ. The recovery increments of vegetationIn mountainous area:On the northern slope is 9.2% / per year, on the southern slope is 9.0% / per year.In hill area:On the northern slope is 8.3% / per year, on the southern slope is 7.6% / per year.Ⅱ. The increasing effects of vegetation on runoff are as follows:1. Shortening the process of runoff, 2. Lowering the peak of flow, 3. Increasing the permeability of the soil, 4. Lessening the amount of runoff.Thus when vegetation increased 1% the coefficient of runoff would be decreased 1.04— 1.2% accordingly. If vegetation increased to 90%, the runoff would be fundamentaly controlled.Ⅲ. The relationship between vegetation and the soil surface erosion are as follows:The relationship between vegetation and soil surface erosion is in inverse proportion.When vegetation is less than 60%, the curve of the soil surface erosion prets a elevation manner by a 45° angle. When vegetation increases to 90%, the soil surface erosion is basicaly controlled.