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.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:699054 |
| Date | January 2016 |
| Creators | Grocott, Michael |
| Publisher | University of Birmingham |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://etheses.bham.ac.uk//id/eprint/6978/ |
Page generated in 0.0018 seconds