降雨强度和坡度对黑土坡耕地团聚体流失特征的影响

为量化雨强和坡度对团聚体流失特征的影响，以黑土坡耕地表层土壤(0—10 cm)为研究对象，采用室内模拟降雨的研究方法，对比了不同雨强(78,127 mm/h)及坡度(2°,4°,6°)下团聚体流失特征，并计算了雨强和坡度对团聚体流失量的贡献率。结果表明：(1)相同雨强条件下，团聚体流失总量随坡度的增加显著增加0.70～1.42倍；相同坡度条件下团聚体流失总量随雨强的增加在坡度4°和6°时分别显著增加1.94,2.41倍。雨强是团聚体流失总量的主要影响因子，贡献率为52.44%;(2)随坡度增加，流失团聚体MWD显著减少，D值仅在雨强78 mm/h时显著增加；随雨强增加流失团聚体MWD,D无显著差异；(3)随坡度增加，粒径5～1,1～0.25,0.25～0.053 mm团聚体流失量呈先增加后减少的趋势，粒径<0.053 mm团聚体流失量显著增加。随雨强的增加，小粒径团聚体流失量呈增加趋势，大粒径团聚体流失量仅在高坡度条件下明显增加；(4)雨强是粒径1～0.25,0.25～0.053,<0.053 mm团聚体流失量的主要影响因素，贡献率为27.42%～47.09%;坡度是粒径5...

Effects of Rainfall Intensity and Slope Gradient on the Characteristics of Soil Aggregate Loss in Black Soil Sloping Field

To quantify the impact of rainfall intensity and slope gradient on characteristics of aggregate losses, black soil slope surface soil(0—10 cm)was selected as the research object, the research method of the simulated rainfall was adopted to compare the aggregate loss characteristics, and calculate the contributions of rainfall intensity and slope gradient to the aggregate loss under different rainfall intensits(78, 127 mm/h)and the slope gradients(2°, 4°, 6°). The results showed that:(1)under the same rainfall intensity, the total losses of aggregates increased by 0.70～1.42 times with the increase of slope gradient; under the same slope condition, the total losses of aggregates increased by 1.94 times and 2.41 times with the increase of rainfall intensity at the slope of 4° and 6°, respectively;(2)with the increase of rainfall intensity, MWD and D had no significant difference; with the increase of slope, the MWD of runoff aggregates decreased significantly, and the D value only increased significantly when the rainfall intensity was 78 mm/h;(3)with the increase of slope, losses of the 5～1 mm, 1～0.25 mm, 0.25～0.053 mm of aggregates presented the trend of increase at first and then decrease, loss of<0.053 mm aggregate increased significantly; with the increase of rainfall intensity, the loss of small aggregates increased, while the loss of large aggregates only increased significantly under the condition of high slope gradient;(4)rainfall intensity was the main influence factor on losses of the 1～0.25 mm, 0.25～0.053 mm, <0.053 mm aggregate, and the contribution rate was 27.42%～47.09%; slope was the main affecting factor on the loss of 5～1 mm aggregate, and the contribution rate was 45.59%. These results can provide the references for clarifying the evolution of the quality of black sloping farmland and preventing soil erosion during hydraulic erosion.