北方土石山区坡面水土流失特征研究OACSTPCD

[Objective]The aims of this study are to reveal the pattern of soil and water loss on the slopes of Northern Rocky Mountain Area,and provide scientific basis for soil erosion control and ecological construc-tion in mountainous areas.[Methods]Based on the observation data of slope runoff plots from 1988 to 1991,the characteristics of soil and water loss on slope under different underlying subsurface conditions were analyzed using statistical and correlation analysis methods,and the relationships among slope runoff depth,soil erosion modulus,soil infiltration rate and effective rainfall,average rainfall intensity,rainfall duration and rainfall grade were discussed.[Results](1)Within the slope range of 5°08′～24°08′,the slope runoff depth gradually decreased with increase of slope gradient,and the soil erosion modulus and soil infiltration rate gradually increased with increase of slope gradient.(2)In the slope length range of 2.18～33.19 m,the slope runoff depth gradually decreased with the increase of slope length,while the soil erosion modulus and soil infiltration rate showed a trend of increasing first and then decreasing with the increase of slope length,and there was a critical slope length.(3)With the increase of vegetation coverage,the slope runoff depth and soil erosion modulus decreased rapidly,and the soil infiltration rate increased gradually.The slope runoff depth and soil erosion modulus of bare land were significantly higher than those of 30％vegetation coverage slope,but the difference in the effect of vegetation coverage increasing from 30％to 60％and 90％on the slope soil erosion process was not obvious,indicating that there was a critical vegetation coverage in soil erosion control.(4)Slope runoff depth and soil erosion modulus were mainly affected by effective rainfall and average rainfall intensity,and both were significantly positively correlated.However,soil infiltration rate was mainly influenced by average rainfall intensity and rainfall duration,and was significantly positively correlated with average rainfall intensity and negatively correlated with rainfall duration.With the increase of rainfall grade,the slope runoff depth and soil erosion modulus showed an increasing trend while the soil infiltration rate increased first and then decreased.[Conclusion]The underlying surface conditions and rainfall factors had important impacts on the soil and water loss process on the slopes in the Northern Rocky Mountain Area.In the future,the research on the process and influence mechanism of different natural factors and human activities on soil and water loss on the slope in this region should be further strengthened in combination with indoor experiments and model simulations.