关键词: 黄土高原, 沟谷侵蚀-堆积模式, 沟谷侵蚀-堆积过程

Abstract: A model was proposed for illustrating gully erosion accumulation processes since the last interglacial. According to this model, the erosion modules and accumulation rates of several erosion and/or accumulation stages for a typical small watershed in the central Loess Plateau of China were quantitatively calculated. Our calculations show that the erosion modules in the selected small watershed have values of 2 126 t/km²穉 during the marine isotope stage 5 (MIS5, 127~73 ka BP) and 972 t/km²穉 during MIS3 (62~26 ka BP), respectively, which are much less than modern erosion module with a value of about 5 000 t/km²穉 in the studied area. The increase of modern erosion module seems to suggest that loess erosion in the central Loess Plateau of China tends to be accelerated presently. Furthermore, gully erosion mainly occurred in the warm and humid interglacial periods, being dominant contributions to the total erosion. During the cold and dry glacial periods, gully development became evidently slowed down or was suspended, and loess deposits accumulated on the gully slope. Our results also demonstrate that gully evolution in the Chinese Loess Plateau is closely linked to paleoclimatic variations, and further indicate that abundant rainfall in the region of the plateau may give rise to occurrence of sediment hazards in the lower Huanghe River.

Key words: Loess Plateau, gully erosion accumulation model, gully erosion accumulation process