黄土高原人类活动对土壤侵蚀的影响

对天然林草植被开垦前后土壤侵蚀变化进行的研究表明，无论林地或砍伐基地地形图因素如何，基本上不发生侵蚀或侵蚀极微弱；而相同地形情况下，开垦地或裸露休闲地年侵蚀模数多在１万ｔ／ｋｍ＾２以上，且受坡度及雨强因素的影响最为明显。人类开荒作用的结果，北洛河上游，延河中上游地区１９５０－１９８４年间年均新增产沙模数３０００ｔ／ｋｍ＾２。晋陕蒙接壤区大型煤田的开采，使得土壤侵蚀进一加剧。如不积极采取防治措施，到

Effects of Human Activities on Soil Erosion in the Loess Plateau

It is shown by the study on variations of soil erosion before and after reclaiming the natural vegetationof forest and grasses that the annual erosion modulus of reclaimed laed or fallow land is more than 10000tons/km2 and is remarkably effected by the factors of slope and rainfall intensity, regardless of topographicfactors of forest land or tree-felling base and under the conditions of same topography of focally no erosion or very slight erosion. Due to the action of human reclamation, the sediment production modulus of annual average increment in 1950-1984 period of the upper Beiluo River and the upper and middle reaches ofthe Yan River is 3000t/km2. The soil erosion is getting worse because of mining a large coalfield in the contiguous areas of shanxi. shaanxi and Inner Mongolia. The sediment entering into the Yellow River will be100 million tons more each year by the year of 2030 if the measccres of prevention and control not beadopted actively.