Preface: Hydrogeology of cold regions

Abstract

Almost half a century ago, Williams (1970) compiled an annotated bibliography of published materials (up to 1960) on permafrost groundwater in the former Soviet Union, United States and Canada, and Scandinavia. That comprehensive survey encompassed literature on permafrost and related temperature and hydrological phenomena, and scientific and applied aspects of groundwater in permafrost terrain. In the intervening years, there have been major advances in permafrost hydrogeology, accompanied by shifts in research emphasis driven by scientific, environmental and societal demands. The present theme issue of Hydrogeology Journal presents a collection of articles that reflect the current status of progress in research on the hydrogeology of cold regions. Several of the papers in this theme issue describe current conditions of resources and processes in different specific regions of the world. Overall, the studies address conditions across different parts of Alaska (USA), Canada, Siberia, China, Fennoscandia and other parts of Europe, and Antarctica. Although snow and seasonally or permanently frozen ground recurs as a common consideration, each paper presents a unique perspective on widely varying conditions. Greater understanding of polar and sub-polar processes may be gleaned from a comparison among these results. With the focus of this thematic issue being on the hydrogeology of cold regions, all the papers in the issue discuss important elements of subsurface hydrology, and there is particular emphasis on ground ice and permafrost interactions with groundwater. However, the studies also deal with externalities that impact the subsurface such as surface energy budget, snow hydrology or glaciers, and groundwater below ice sheets, and some contributions address subsurface controls on the surface conditions via interaction with surface water or ecology. With regard to investigation approaches, the studies deal with interpretation of field or remotely sensed data, theory of ice-impacted hydrologic processes, field techniques, and modeling of groundwater systems in cold regions. Some of themodeling papers combine in pointing at safety assessment of nuclear waste repositories under climate-cooling scenarios as an important motivation for development and application of numerical simulation approaches for the hydrogeology of cold regions. Some articles are about management of groundwater resources, and there is also some discussion on societal aspects of cold-regions hydrology, for example, impacts of climate warming in these regions. In summary, the range of investigations presented in this thematic issue constitutes a valuable compilation of the state of knowledge of cold region hydrogeology. This contribution is timely, with groundwater resources in cold regions facing immediate or impending changes as a consequence of the ongoing climate change, the intensification of the hydrologic cycle, and in response to increased demands from communities and industry.