**5. Conclusions**

In this study, we added the impact of terrace and vegetation practice on runoff and sediment routing in the time-area method. The revised time-area method was integrated into the LCM-MUSLE model which is suitable to estimate the water and sediment yield in the Loess Plateau. Eight isolated storm events in the 1980s and 2010s in Pianguanhe Basin were selected to calibrate and verify the original LCM-MUSLE model and its revised version. It is shown that the original model was not applicable in the more recent years, since the surface had changed significantly as a result of revegetation and terrace engineering. The revised model considered the impact of vegetation and terracing on runoff and sediment routing and its accuracy had been improved significantly.

The effect of the level terraces and vegetation was parameterized effectively according to their location, size, embankment height, and vegetation coverage. These parameters could be easily obtained and were used to represent the landscape heterogeneity at the catchment scale. Besides, the revised time-area method was loosely coupled with the LCM-MUSLE model. Therefore, the method could be readily applied in other regions and integrated into other hydrological models and erosion models. Consequently, this study provides a generalized method to quantitatively assess the impact of terrace and vegetation practice on runoff and sediment reduction at the catchment scale, which has great significance in runoff change analysis and implementation of soil and water conservation.

*Water* **2019**, *11*, 803

**Author Contributions:** J.B. conceived and designed the experiments; J.B. and Y.Z performed the experiments; Y.G. contributed analysis tools; J.B., S.Y. and X.L. analyzed the data; J.B. and Y.Z. prepared figures; J.B. wrote the main manuscript text.

**Funding:** The authors are also thankful for the financial support from the National Key Project for R&D (Nos. 2016YFC0402403, 2016YFC0402409), the National Natural Science Foundation of China (Grant Nos. U1603241, 51779099), and the Fundamental Research Funds for Central Public Welfare Research Institutes (HKY-JBYW-2017-10).

**Acknowledgments:** We acknowledge all of the editors and reviewers for their valuable advice.

**Conflicts of Interest:** The authors declare no conflict of interest. The founding sponsors had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript; and in the decision to publish the results.
