关键词: 流域分布式土壤侵蚀学坡长, 地形因子, 多维复合集成模型, 地形复杂度, 土壤侵蚀, 黄土丘陵沟壑区

Abstract: As one of the most basic parameters of watershed and regional scale hydrological model and soil erosion model, spatially distributed slope length has an important impact on the formation and development of soil erosion. Based on the common shape factors in loess hilly and gully region, the relationship between slope length and terrain was discussed in detail. On this basis, a multi-dimensional composite integration model of terrain element interaction was established, and the contribution of each topographic element to slope length in the study area was calculated quantitatively. Then the influence of topography on soil and water loss was revealed. The results showed that (1) the contribution rate of complex terrain factors to slope length is higher, which can better reveal the influence of terrain on soil and water loss. (2) seven composite terrain factors contribute positively or negatively to slope length, without an same law.(3) the contribution rate of terrain factors to slope length from high to low are slope spectrum information entropy, roughness, elevation area integral, fluctuation, altitude standard deviation, average slope, section curvature, plane curvature, gully density.

Key words: distributed erosion slope length, topographic factors, multi-dimensional composite integration model, terrain complexity, soil erosion, loess hilly and gully region