米脂县黄土滑塌分布及其对流域产沙的影响

Distribution of Loess Slide and Its Influence on Sediment Yield in Mizhi County

土壤重力侵蚀在黄土高原流域产沙中占有很大比重。黄土重力侵蚀主要有滑坡、滑塌、泻溜和崩塌四种方式,其中以滑坡发生规模最大,分布也比较普遍。但是,滑坡并不是经常发生的,而且,由于滑坡产生后土体地貌条件由不稳定变得相对稳定,反而对流域产沙产生抑制作用。因此,如果将重力侵蚀看作影响黄土高原流域产沙的重要因素,那么主要指的应该是黄土滑塌、泻溜和崩塌。

Loess slide is a kind of block movement along the slope surface under the action of gravity and also a major type of gravitational erosion in the Loess Plateau. Using the Mizhi County in Shaanxi Province as an example, this paper analyses the influence of soil texture, geomorphology and climate on the formation of loess slide and the impact of loess slide on sediment yield based on the relevant data obtained by remote sensing method. The results indicate that the distributions of loess slide in different regions differ obviously. The loess slides distribute mainly on both side of the watershed divide and sediment yield in a watershed increased obviously at places where the slides take place frequently. So in the work of soil and water conservation in the loess plateau region,destruction of erosion in form of slide to the land resources should be considered seriously.