Abstract Many studies have confirmed that terrain is an important factor affecting cadmium (Cd) accumulation in soil. However, the literature offers limited exploration on the effect mechanism of terrain on soil Cd accumulation. This study aims to explore the effect of terrain on the characteristics and influencing factors of soil Cd accumulation. A total of 182 soil samples are collected across the terrain gradient from soils in Dongguan City. Gradient boosting decision tree is implemented to identify the influencing factors of Cd accumulation in different terrain gradients. The goodness of fit of the models for low, median, and high terrains are 0.85, 0.80, and 0.84, respectively. Cd accumulation shows a significantly decreasing pattern in soils with an increase in terrain gradient (P industrial production (CV, 74.6%) > soil properties (CV, 39.3%) > domestic wastes (CV, 26.1%) > traffic emission (CV, 17.9%) > mining (CV, 15.8%). When the terrain niche index is>1.50, the relative contribution of agricultural practices decreases sharply (24.26%) and that of industrial production shows a rapid increase (25.88%). The main reason for this phenomenon is that agricultural practices are more restricted by terrain gradient than industrial production. These findings imply that the differences of characteristics and influencing factors of Cd accumulation with terrain gradient must be considered in the formulation of targeted polices for controlling Cd contamination in soils.

中文翻译：

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地形坡度对土壤镉积累的影响

摘要 许多研究证实，地形是影响土壤中镉（Cd）积累的重要因素。然而，文献对地形对土壤 Cd 积累的影响机制提供了有限的探索。本研究旨在探讨地形对土壤Cd积累特征及影响因素的影响。从东莞市土壤中跨越地形梯度共采集了182个土壤样品。实施梯度提升决策树，识别不同地形梯度下Cd积累的影响因素。低地、中地和高地模型的拟合优度分别为 0.85、0.80 和 0.84。随着地形梯度的增加（磷工业生产（CV，74.6%）>土壤特性（CV，39.3%）> 生活垃圾（CV，26.1%）> 交通排放（CV，17.9%）> 采矿（CV，15.8%）。当地形生态位指数>1.50时，农业实践的相对贡献急剧下降（24.26%），而工业生产的相对贡献则呈现快速上升（25.88%）。造成这种现象的主要原因是，与工业生产相比，农业实践更多地受到地形坡度的限制。这些发现意味着，在制定控制土壤镉污染的针对性政策时，必须考虑到土壤中镉积累的特征和影响因素随地形梯度的差异。26%），工业生产增长较快（25.88%）。造成这种现象的主要原因是，与工业生产相比，农业实践更多地受到地形坡度的限制。这些发现意味着，在制定控制土壤镉污染的针对性政策时，必须考虑到土壤中镉积累的特征和影响因素随地形梯度的差异。26%），工业生产增长较快（25.88%）。造成这种现象的主要原因是，与工业生产相比，农业实践更多地受到地形坡度的限制。这些发现意味着，在制定控制土壤镉污染的针对性政策时，必须考虑到土壤中镉积累的特征和影响因素随地形梯度的差异。