Soil moisture is strongly spatially variable and scale dependent, but there is a lack of research focusing on factors that link soil actual evaporation to the spatial distribution of topsoil moisture at the slope scale. External factors (e.g., meteorological) have similar effects across entire slopes; hence, this paper instead explores the internal factors controlling differential soil actual evaporation. We consider the effects of historical rainfall on soil erosion, and adopt a combined approach encompassing slope investigations, a slope rainfall simulation experiment, slope erosion analyzed by 3D laser terrain scanning, and evaporation experiments. Along the runoff direction, we show that the relative topsoil clay content increases, but slope surface deformation and failure lead to a decrease in the relative content of clay in deposits located on the lower of slope. The original thickness of slope surface decreases in the upper part of the slope, due to particle migration, while the slope surface relatively far away from the upper part of the slope tends to be thicker, due to the accumulation of slope deposits. The actual evaporation of the topsoil relatively far from the upper part of the slope is significantly weaker (63%–72% probability), which may be related to the high clay content, dense soil structure, and high content of clay minerals. The topsoil evaporation also tends to weaken as overburden thickness increases. Here, we suggest that marked differences in the original thickness of the slope surface and in the properties of the topsoil caused by the migration and deposition of soil particles under successive years of rainfall erosion, are important factors controlling differences in topsoil actual evaporation in different parts of the slope. This understanding lays the foundation for the analysis of hydrological processes in different parts of a slope, which is crucial for the study of shallow slope mechanical behavior.

土壤水分在空间上具有很强的可变性和尺度依赖性，但缺乏将土壤实际蒸发与斜坡尺度表土水分空间分布联系起来的因素的研究。外部因素（如气象）在整个斜坡上都有类似的影响；因此，本文转而探讨控制差异土壤实际蒸发的内部因素。我们考虑了历史降雨对土壤侵蚀的影响，采用了坡度调查、坡度降雨模拟实验、3D激光地形扫描分析坡度侵蚀和蒸发实验的综合方法。沿径流方向，我们表明相对表土粘土含量增加，但坡面变形和破坏导致位于坡下部的沉积物中粘土的相对含量降低。坡面的原始厚度在坡面上部由于颗粒迁移而减小，而距离坡面上部较远的坡面由于坡面沉积物的堆积而趋于增厚。离坡上部相对较远的表层土壤实际蒸发明显减弱（概率为63%~72%），这可能与粘土含量高、土壤结构致密、粘土矿物含量高有关。随着覆盖层厚度的增加，表土蒸发也趋于减弱。这里，我们认为，在连年降雨侵蚀下，由于土壤颗粒的迁移和沉积导致坡面原始厚度和表土性质的显着差异，是控制不同地区表土实际蒸发差异的重要因素。坡。这一认识为分析边坡不同部位的水文过程奠定了基础，这对于研究浅层边坡力学行为至关重要。