Whereas current erosion models are successful in quantitative estimates of soil erosion by water flow, modeling the coevolution of geomorphological features, particularly rill network properties and soil erosion on hillslopes, is still a major challenge. In this study, we propose a rill evolution modeling approach and combine it with a rainfall‐runoff and soil erosion model to simulate the feedback loop of hillslope geomorphic development and soil erosion processes. Rill evolution is mainly characterized by three rill network attributes, rill density, orientation angle, and rill width, all modeled with physical equations. The entire rainfall‐runoff‐erosion and rill evolution model is tested against a set of rill network evolution and soil erosion data from an experimental hillslope subjected to successive rainfall events. The simulated spatial and temporal variations of rill network characteristics and soil erosion agree well with the measured data. The results demonstrate that the three rill network characteristics continually alter the partitioning of interrill and rill flows and affect the interrill and rill flow erosivity and soil erosion, which in turn modify the rill geometry and rill network planform. Comparatively, existing approaches such as Water Erosion Prediction Project (WEPP) that ignore the rill evolution processes largely underestimate the hillslope soil erosion when using time independent model parameters. Moreover, a sensitivity analysis indicates that both the rill evolution and soil erosion processes are sensitive to the rill evolution parameters, rainfall intensity, and slope angle. These results can inform the development of general geomorphic evolution and soil erosion models on evolving rilled hillslopes.

中文翻译：

---

用不断变化的山坡上的土壤流失模拟土壤侵蚀

尽管目前的侵蚀模型可以成功地定量估算水流对土壤的侵蚀，但是对地貌特征的共同演化建模，特别是对山坡上的钻探网络特性和土壤侵蚀的建模，仍然是一个重大挑战。在这项研究中，我们提出了一种小溪演化建模方法，并将其与降雨径流和土壤侵蚀模型相结合，以模拟坡地地貌发育和土壤侵蚀过程的反馈回路。罗尔演变的主要特征是三个钻探网络属性，钻探密度，定向角和钻探宽度，所有这些都使用物理方程建模。整个降雨－径流－侵蚀和小溪演化模型是根据一组经历连续降雨事件的实验性山坡上的小溪网络演化和土壤侵蚀数据进行测试的。演习网络特征和土壤侵蚀的模拟时空变化与实测数据吻合良好。结果表明，三种钻探网络特征不断地改变了钻探和钻探流的分配，并影响了钻探和钻探流的侵蚀性和土壤侵蚀，从而改变了钻探的几何形状和钻探网络的平面形式。相比之下，当使用时间独立模型参数时，诸如水蚀预测项目（WEPP）之类的现有方法忽略了小溪的演变过程，在很大程度上低估了山坡土壤侵蚀。此外，敏感性分析表明，小溪演化和土壤侵蚀过程对小溪演化参数，降雨强度和坡度角均敏感。