Abstract Current physically based erosion models do not carefully consider the dynamic variations of soil properties during rainfall and are unable to simulate saline-sodic soil slope erosion processes. The aim of this work was to build upon a complete model framework, SSEM, to simulate runoff and erosion processes for saline-sodic soils by coupling dynamic saturated hydraulic conductivity Ks and soil erodibility Kτ . Sixty rainfall simulation rainfall experiments (2 soil textures × 5 sodicity levels × 2 slope gradients × 3 duplicates) provided data for model calibration and validation. SSEM worked very well for simulating the runoff and erosion processes of saline-sodic silty clay. The runoff and erosion processes of saline-sodic silt loam were more complex than those of non-saline soils or soils with higher clay contents; thus, SSEM did not perform very well for some validation events. We further examined the model performances of four concepts: Dynamic Ks and Kτ (Case 1, SSEM), Dynamic Ks and Constant Kτ (Case 2), Constant Ks and Dynamic Kτ (Case 3) and Constant Ks and Constant Kτ (Case 4). The results demonstrated that the model, which considers dynamic variations in soil saturated hydraulic conductivity and soil erodibility, can provide more reasonable runoff and erosion prediction results for saline-sodic soils.

中文翻译：

---

SSEM：模拟沿海开垦下盐碱土斜坡径流和侵蚀的模型

摘要 当前基于物理的侵蚀模型没有仔细考虑降雨过程中土壤性质的动态变化，无法模拟盐碱土坡面侵蚀过程。这项工作的目的是建立一个完整的模型框架 SSEM，通过耦合动态饱和导水率 Ks 和土壤可蚀性 Kτ 来模拟盐碱土的径流和侵蚀过程。60 次降雨模拟降雨实验（2 个土壤质地 × 5 个碱度水平 × 2 个坡度梯度 × 3 个重复）为模型校准和验证提供了数据。SSEM 非常适合模拟盐碱粉质粘土的径流和侵蚀过程。盐碱土的径流侵蚀过程比非盐碱土或粘土含量较高的土壤更为复杂；因此，SSEM 在某些验证事件中表现不佳。我们进一步检查了四个概念的模型性能：Dynamic Ks and Kτ（Case 1, SSEM）、Dynamic Ks and Constant Kτ（Case 2）、Constant Ks and Dynamic Kτ（Case 3）和Constant Ks and Constant Kτ（Case 4） . 结果表明，该模型考虑了土壤饱和导水率和土壤可蚀性的动态变化，可为盐碱土提供更合理的径流侵蚀预测结果。