植被破坏与恢复对坡面浅沟侵蚀影响的研究

Impact of Vegetation Destruction and Restoration on Shallow Gully Erosion

运用野外实测资料,分析研究了子午岭林区植被破坏与恢复对坡面浅沟侵蚀的影响。所得结论为:一旦植被恢复,坡面浅沟沟槽部位发生泥沙淤积,其淤积速度为0.5cm/a;浅沟沟槽部位淤积,坡面横向起伏减少,坡面向平直方向发展。人为破坏植被后的开垦地,坡面浅沟侵蚀急剧发展,浅沟侵蚀量为4400～7600t/(km^2·a),占坡面侵蚀量的47%以上;当年新冲刷的浅沟沟槽宽为20～80cm,深度为10～30cm;开垦3年裸露地与林地相比,浅沟沟槽深度增加40～60cm;浅沟沟头前进速度为3～5m/a,浅沟深、宽、长的逐年发展,坡面横向起伏加大,片蚀和细沟侵蚀随之加大,又促使了浅沟侵蚀的加剧。

Effect of vegetation and restoration on shallow gully erosion has been researched in this paper,using survey data.The results show that once vegetation was restored,shallow gully trough occured sediment deposition,the deposition speed is 0.5era/a,undulation of cross section, in slope surfae was decreased caused by shallow gully sediment deposition,development of the slope surface inclined to level,After vegetation being destroyed,shallow gully erosion rapidly de- velops,amount of shallow gully erosion is 4400～7 600t/km^2·a,it occupys above 47% of soil erosior amount on the slope surface.Washing width and depth of gully trough of shallow gully are 20～80cm and 10～30cm respectively.Compared reclaimed land after reclaimed 3 years with forest land,gully trough depth of shallow gully increases 40～60cm.The speed of shallow gully head back ward erosion is 3～5m/a,Because of development of lenth,width and depth of shallow gnlly,undulating of cross section in the slope surface increases,sheet and rill erosion increases, which intensifys development of shallow gully erosion,and undulating of cross section in the slope surface inclines to becoming big.