Abstract: Using the digital elevation data of “Sudalaer”, a typical desert watershed from ten tributaries area in the Upper Yellow River, and taking the processes and types of loess bank as the reference group, the process and types of desert coarse sand bank collapse under steady rainfall infiltration conditions in the Upper Yellow River were studied through Strength Reduction Theory based generalized numerical simulation as well as field observation analysis. The results indicate that under the influence of cohesive force, the coarse sand bank slope is mainly in the state of layering and flaky slumping, while the loess bank slope is mostly in the state of block or mass slumping. Compared with the arc sliding of loess bank slope, the coarse sand bank slope presents a broken line sliding, and the collapse pattern is upright, which is qualitatively consistent with the measured results.

Key words: the Upper Yellow River, coarse sand bank, gravitational erosion, collapse processes and type, strength reduction theory