Abstract. The topography is a critical factor that determines the characteristics of regional soil formation. Small-scale topographic changes are defined as microtopographies. As a characteristic topographic condition in hilly mountainous regions, the redistribution of water and soil materials caused by microtopography is the main factor affecting the spatial heterogeneity of soil and the utilization of land resources. In this study, the influence of microtopography on pedogenesis was investigated using soil samples formed from mudstones with lacustrine facies deposition in the middle of the Sichuan Basin and developed into hill landforms by erosion of flowing water. Soil profiles were sampled along the slopes at the summit, shoulder, backslope, footslope, and toeslope positions. The morphological, physiochemical, and geochemical attributes of profiles were analysed. The results showed that the soil thickness increased significantly with changes in the soil profile configuration from the summit to the toeslope, and the profile configuration changed from A-C to A-B-C. The migration direction of Ca and Na at the summit, backslope, and footslope changed from enrichment to leaching, whereas that of Al, Fe, and Mg changed from leaching to enrichment. At the summit and shoulder of the hillslope, weathered materials are transported away by gravity and surface erosion, and new rocks are often exposed; therefore, the characteristics of soil development is relatively weak. However, in flat areas such as the footslope and toeslope with sufficient water conditions, the long-term contact between water, soil, and sediment leads to further chemical weathering, resulting in highly developed characteristics. Microtopography can affect physicochemical properties, chemical weathering, and redistribution of water and materials, resulting in differences in pedogenic characteristics at different slope positions.

中文翻译：

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微地形如何影响丘陵山区泥岩土壤的成土特征？

摘要。地形是决定区域土壤形成特征的关键因素。小规模的地形变化被定义为微地形。作为丘陵山区特有的地形条件，微地形引起的水土物质重新分布是影响土壤空间异质性和土地资源利用的主要因素。在这项研究中，利用四川盆地中部湖相沉积泥岩形成并经流水侵蚀发展成丘陵地貌的土壤样本，研究了微地形对成土作用的影响。在山顶、肩部、后坡、脚坡和脚坡位置沿斜坡采样土壤剖面。形态学、理化、分析了剖面的地球化学属性。结果表明，随着土壤剖面形态从山顶到坡脚的变化，土壤厚度显着增加，剖面形态由AC变为ABC。Ca、Na在山顶、后坡、坡脚的运移方向由富集向淋滤转变，Al、Fe、Mg的运移方向由淋滤向富集转变。在山坡的顶峰和肩部，风化物质被重力和地表侵蚀带走，常有新的岩石出露；因此，土壤发育的特点是比较弱的。但在坡脚、坡脚等水分条件充足的平坦区域，水土泥沙长期接触，化学风化进一步加剧，导致高度发达的特征。微地形会影响物理化学性质、化学风化以及水和物质的重新分布，导致不同坡位的成土特征存在差异。