• 论文 •

### 黄土地区梁峁坡的坡地特征与土壤侵蚀

1. 中国科学院地理研究所
• 收稿日期:1982-04-16 修回日期:1983-01-12 出版日期:1983-09-15 发布日期:1983-09-15

### SLOPE FEATURES AND SOIL EROSION IN THE LOESS REGION

Cao Yinzhen

1. Institute of Geography, Academia Sinica
• Received:1982-04-16 Revised:1983-01-12 Online:1983-09-15 Published:1983-09-15

Abstract: In this paper the relationship between slope features and soil erosion in the loess region has been studied. Investigation shows that the angles of slopes of loess ridge and hill mostly vary from 14° to 28° The upper limit of the characteristic angles corresponds to the angle of internal friction of loess and the lower limit to half of the angle. This is coincident with the results stated by Carson (1969).The slope forms in the loess region can be separated into five types, namely straight, convex, concave, concave-convex and step slopes. The erosion position is very different on the different kind of the slopes. It mostly occurs on the downslope of the straight slope, on the mid-down slope of the convex slope, on the mid-slope of the concave slope and on the straight segments between the convex and concave elements of concave-convex and step slope.Soil erosion is greatly controlled by slope angles. The statistical analysis of the data observed in the fields shows that 15°, 26° and 45° are very important to soil erosion. The sediment yields increase with slope angles, then over 15° the sediment yields rapidly rise and washing is greatly intensified. At 26° the way of erosion changes, from the running water wash to gravitational erosion. At 45° erosion is the most intense in the slope angles between 0° and 90°. This result is supported by the mathematical deduction. The study of the three slope angles is important in both theoretical research and reasonble planning for controlling the drainage basin in a comprehensive way.