**Preface to "Advanced Hydrologic Modeling in Watershed Scales"**

Hydrologic modeling at the watershed scale is a key topic in the field of hydrology. The hydrological model is an important tool to understand the impact of climate change and human activities on rainfall–runoff processes, and especially on water resources for human beings in a changing environment. In the last two decades, with the development of satellite remote sensing and artificial intelligence, many new datasets and methods have been introduced into hydrological modeling.

Hydrologic modeling at the watershed scale is an important and fundamental research field in hydrology. Therefore, we proposed a Special Issue entitled "Advanced Hydrologic Modeling in Watershed Scales"in *Water* to publish findings regarding the recent progress in hydrological modeling at the watershed scale against global changes. Before the deadline for the submission of manuscripts to this Special Issue, we received many manuscripts regarding hydrological modeling at the watershed scale. In total, ten articles have been published in this Special Issue.

In the simulation of hydrological processes, the SWAT model was applied in five case studies, which were in the Bayin River basin of China, the Fengle watershed in the middle–lower Yangtze Plain of China, the Tangbai River Basin crossing Henan province and Hubei province in China, twelve hydrological sites in the Illinois River watershed in the U.S., and the Wei River Basin on the Loess Plateau in China. At the same time, runoffs were simulated using other models or methods, such as the Hydrological Engineering Center–Hydrological Modeling System (HEC-HMS), a two-stage annual precipitation partitioning method; the Xin An Jiang model; and the GR3 model. In addition, an integrated approach based on remote sensing and GIS using the influence factor (IF) technique was utilized to delineate potential groundwater recharge zones in Islamabad, Pakistan.

Based on hydrological modeling, these studies promoted have our understanding of the impact of vegetation changes on hydrological processes, the performance of meteorological datasets and precipitation datasets, hydrologic and nutrient cycling, a new hybrid SWAT-WSVR model, the relationship between the SWAT model parameters and the factors, the simulation of snowmelt runoff, the impact of climate change and human activities on the annual total stream flow and base flow, the difference between the calibrated objective functions, the simulation of the hydrological process with the background of inter-basin water transfer, and potential groundwater recharge zones.

Researchers interested in hydrological modeling and the impacts of environment change on water resources may be interested in this reprint. This Special Issue, entitled "Advanced Hydrologic Modeling in Watershed Scales" in *Water*, was handled by the Guest Editors, Dr. Dengfeng Liu, Dr. Hui Liu, and Dr. Xianmeng Meng. We acknowledge the editors of the journal, especially Ms. Sanja Vuciˇ c, for her help in processing the articles. ´

> **Dengfeng Liu, Hui Liu, and Xianmeng Meng** *Editors*
