Abstract. The sensitivity of chemical weathering to climatic and erosional forcing is well established at regional scales. However, soil formation is known to vary strongly along catenas where topography, hydrology, and vegetation cause differences in soil properties and possibly chemical weathering. This study applies the SoilGen model to evaluate the link between topographic position and hydrology with the chemical weathering of soil profiles on a north-south catena in southern Spain. Pedogenesis was measured and simulated in seven selected locations over a 20000-year period. A good correspondence between simulated and measured chemical depletion fraction (CDF) was obtained (R² = 0.47). An important variation in CDF values along the catena was observed, although the position along the catena alone, nor by the slope gradient, explained this variation well. However, the hydrological variables explained the observed trends better. A positive trend between CDF data and soil moisture and infiltration and a negative trend with water residence time was found. The model sensitivity was evaluated with a large precipitation gradient (200–1200 mm yr⁻¹). While a marked depth gradient was obtained for CDF with precipitation up to 800 mm yr⁻¹, a uniform depth distribution was obtained with precipitation above 800 mm yr⁻¹. The basic pattern for the response of chemical weathering to precipitation is a unimodal curve, with a maximum around a mean annual precipitation value of 800 mm yr⁻¹. Interestingly, this corroborates similar findings on the relation of other soil properties to precipitation and should be explored in further research.

中文翻译：

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模拟链位置和水文对土壤化学风化的影响

摘要。化学风化对气候和侵蚀强迫的敏感性在区域尺度上得到了很好的确立。然而，众所周知，土壤形成沿连环变化很大，其中地形、水文和植被会导致土壤特性的差异和可能的化学风化。本研究应用 SoilGen 模型来评估地形位置和水文与西班牙南部南北连线土壤剖面化学风化之间的联系。在 20000 年的时间里，在七个选定的地点测量和模拟了成土作用。获得了模拟和测量的化学损耗分数 (CDF) 之间的良好对应关系 (R ² = 0.47）。观察到沿链的 CDF 值的重要变化，尽管仅沿链的位置，也不由坡度梯度，很好地解释了这种变化。然而，水文变量更好地解释了观察到的趋势。发现 CDF 数据与土壤水分和入渗之间呈正趋势，而与水停留时间呈负趋势。使用大降水梯度（200-1200 mm yr ^-1）评估模型敏感性。虽然降水量高达 800 mm yr ^{-1 的}CDF 获得了显着的深度梯度，但降水量超过 800 mm yr ^{-1 时}获得了均匀的深度分布. 化学风化对降水响应的基本模式是单峰曲线，最大值在年平均降水值 800 mm yr ^{-1 附近}。有趣的是，这证实了其他土壤性质与降水关系的类似发现，应在进一步研究中进行探索。