坡面土壤侵蚀空间分异特征的磁性示踪法和侵蚀针法对比研究

Comparative on Characteristics of Soil Erosion Spatial Variation on Slopes Using Magnetic Tracing and Erosion Pins

利用磁性示踪法和侵蚀针法相结合的方法,在自然降雨条件下对比研究了不同坡度坡面土壤侵蚀的空间分异特征。结果表明:磁性示踪法和侵蚀针法均能够有效的指示出在降雨过程中坡面土壤发生剥蚀和沉积的空间分布规律。两种方法的试验结果一致表明,在距坡顶0-200cm的范围内为净侵蚀区,坡面坡度越大受到的侵蚀越严重。坡面中下部(距坡顶200-500cm)侵蚀沉积分布受坡度影响较大,随着坡度的增大,坡面中下部的沉积分布下移,并且净沉积量减少,净剥蚀量增加。5°坡面中下部以泥沙的沉积为主,且在中部沉积量达到最大值;10°和15°坡面的中部和坡脚处以侵蚀为主,沉积主要发生在距坡顶300-400cm的范围内。

Applying the methods of Magnetic Tracing combined with Erosion Pins,research was did,under the natural rainfall conditions and three slope gradients（5°,10°and 15°）,on the characteristics of soil erosion spatial variation. The results showed that the two methods can both effectively indicate the erosion and deposition of different spatial and their distribution along the slope in the natural rainfall. The section at the range 0-200 cm from the top was net erosion section,and greater the slope gradient,more serious erosion was. The distribution of erosion and deposition in the middle and lower parts of the slope land was significantly influenced by the gradient. With the increasing of slope gradient,the section of deposition shifted down in the middle and lower parts of the slope land and the net deposition amount reduced,while the net erosion amount increased. Sediment deposition was the main process in the middle and lower parts of the 5°slope and the amount of deposition in the middle reached the greatest value. The erosion was the main process in the middle and the foot of 10°and 15°slopes and deposition mainly occurred at the range 300-400 cm from the top.