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地貌是黄土沟道中重力侵蚀发生的重要条件。基于对黄土沟壑区桥沟小流域的实地观测和DEM数据,从沟道侵蚀的垂直分带性、沟道地貌发育的阶段性、坡面坡度分布等方面分析了流域地貌因素对重力侵蚀的影响。研究表明,桥沟流域存在<20°、20°～32°、32°～42°、>42°四个类型的坡面,其中30°左右是梁峁坡的临界坡面,40°左右是坡积物堆积坡的临界坡面,42°以上可以作为沟坡的判定界限。对不同坡度坡面水流输沙能力进行对比,可以估算出桥沟流域典型坡面重力侵蚀产沙量占总产沙量的42%左右。
Landform is an important condition of gravity erosion in loess channel. Based on the field observation and DEM data of Qiaogou small watershed in loess gully area, the effects of watershed topography on gravity erosion are analyzed from the aspects of the vertical zonation of channel erosion, the stage of channel topography development and slope gradient distribution . The results show that there are four types of slopes of <20 °, 20 ° ~ 32 °, 32 ° ~ 42 °,> 42 ° in Qiaogou watershed. About 30 ° is the critical slope of Beam slope, about 40 ° Slope accumulation of the slope slope of the critical slopes, 42 ° above can be used as the judgment of the ditch slope. Comparing the runoff and sediment transport capacity of different slopes, it can be estimated that the gravity erosion and sediment yield of typical slope in Qiaogou watershed is about 42% of the total sediment yield.