gully in Loess Ravine Region

In the small watershed of the Loess Ravine Region, the highest soil loss normally occurs at the gully. Hence erosion of the gully is important for conservation practice allocation, disaster prevention and mitigation, and sustainable development in this area. Experiments with models of different slope gradients and slope heights were carried out under the simulated rainfalls, and the amount of soil and water loss was quantitatively analyzed in this study. The results were as follows: 1) the gravitational erosion played an important role in the hyperconcentrated flows, although not all mass failure could lead to hyperconcentrated flows; 2) the sediment concentration and the sediment transport rate increased with the rainfall duration, especially in the later rainfall events; 3) for the outlet runoff in different rainfall events, the variation trend of the average soil content of the whole rainfall event was consistent to that of the later stage of the event; 4) the sediment concentration and the sediment transport rate increased with the slope gradient, but had no correlation with the slope height. Consequently gravity erosion has an important effect on the process of soil loss from the gully in the Loess Ravine Region.