The cold regions in the globe are experiencing the most rapid climate changes. Snow and ice dominate hydrology of cold regions. Our understanding of the hydrologic response to a changing climate in the cold regions, including the high latitudes and altitudes, is incomplete. Our ability to model the effect of climate and hydrology changes in the cold regions needs improvement. This session will address major issues and challenges in cold region hydrology research and applications, such the changes in the nature, structure, and function of the cold region rivers, lakes, and wetlands, and their interactions with human activities and the ecosystems. It will also explore and examine the biological, physical, and social impacts of hydrology and climate changes in the cold regions. This session welcomes contributions from various research aspects, including field process study, analysis of long-term records, modeling approach, remote sensing application, and synthesis of major regional and international research projects.