Hydrology of paraglacial catchments in a changing climate: impacts on biodiversity hotspots

[摘要] Groundwater (GW) -fed streams are a common feature of paraglacial floodplains and are regarded as ‘biodiversity hotspots’, due to their role as valuable aquatic habitats. The hydrological dynamics which support GW-fed streams remain poorly understood. There is a need to improve understanding given paraglacial environments are extremely sensitive to the impacts of climate change. To address this significant knowledge gap site specific research was conducted on GW-fed streams within Denali National Park & Preserve, Alaska, during 2013 and 2014. Hydrometric, hydrochemical, hydrogeomorphic, and geophysical techniques were utilised to improve understanding of the hydrological dynamics and hydrogeomorphic controls that influence GW-fed stream occurrence. Paleochannels across paraglacial floodplains were identified as important preferential flow pathways (PFPs); and a first-order control upon GW-fed streams. In addition hillslope-runoff was established as an important hydrological flux to GW-fed streams. Colluvial deposits (e.g. talus cones) were highlighted as valuable hydrological stores on valleys-sides that made a direct contribution to streamflow. This research has raised concerns about the long-term stability of GW-fed streams in paraglacial environments due to changes in hydrogeomorphic controls (PFPs). It has also raised more immediate concerns about the short- to medium-term implications of shifting hydrologic regimes (e.g. declining winter snowpack) for GW-fed streams.

[发布机构] University:University of Birmingham;Department:School of Geography, Earth and Environmental Sciences

[关键词] G Geography. Anthropology. Recreation;GB Physical geography