Special Issue on Advances in the Fundamental Study, Numerical Simulation, and Prediction of Hydrologic Processes in River Basins

The impacts of environmental changes, such as climate and land use–land cover changes, on the hydrologic system have increased at regional and global scales in the last few decades. As a result, environmental consequences in large-scale river basins, like floods and droughts, and the management of these basins require the understanding of contributing watersheds within the basin. Studying hydrologic processes and numerical simulation and prediction of these processes under the influence of climate changes and human activities within the river basin are crucial to many environmental aspects, such as the development and utilization of water resources, and mitigation of the disasters of floods and droughts.

Many programs and projects, such as “The Impact of Climate Change on the Hydrologic Cycle and Assessment of Water Resource Security in the Region of Yellow River, Huaihe River, and Hai River,” have been aimed to evaluate the impact of climate change on the hydrologic cycle, to examine climate change–driven mechanisms of floods and droughts, and to assess the influence of climate change on regional water resources. This special issue consists of a series of papers in different basins. The topics covered by the papers include (1) the assessment of impacts of climate change on hydrologic processes, such as streamflow and sediment transport; (2) the hydrologic response (e.g., evapotranspiration and runoff) to the land use–land cover changes; (3) model development and application of hydrologic simulations; and (4) hydrologic analysis and simulation with the integrated remote sensing and advanced techniques. These studies present recent advances in the fundamental study, numerical simulation, and prediction of hydrologic processes in river basins.

The interactive links among the land-surface and subsurface processes and atmospheric processes are very important in current research efforts to understand how perturbed climate conditions (both human-induced and natural) can modify basin-scale hydrologic systems and, in turn, how the modified hydrologic conditions can influence the climatic system. Although many advances in these research areas have been achieved, the comprehensively integrated basin approach with data assimilation and analysis (e.g., satellite and radar data) is required to address various aspects of impacts of environmental changes (e.g., climate change and land use–land cover changes) on the hydrologic system, such as the understanding of hydrologic processes in response to these changes, the representation of basin-scale processes in large-scale climate and hydrology models, and application of these further scientific advances in the basin-scale decision making.