Overview:
There has been growing interest in the roles that hyporheic zones and
riparian zones play in catchment-scale budgets of nutrients, heat, and
energy. Because streams are intimately connected to hyporheic and
riparian zones, these biogeochemical “hot spots”, or zones of enhanced
biogeochemical cycling, directly influence water quality of streams.
Significant research has been conducted on the biogeochemical and
hydrologic functions of both hyporheic and riparian zones, though often
in isolation from each other. In this proposal, we seek to determine
how dynamic valley-bottom (riparian) hydrology is controlled by valley
morphology and gradient, and how this in turn influences hyporheic
exchange throughout summer baseflow recession in headwater catchments.
We pose the following research questions:
1) How do the relative magnitudes of down-valley and cross-valley vectors of riparian subsurface flow change throughout seasonal baseflow recession?
2) How are these changes controlled by valley-scale morphology and gradient?
3) How spatially consistent (at the reach scale) are the patterns of down-valley and cross-valley vectors of flow?
4) In response to seasonal changes in relative magnitudes of down-valley and cross-valley flow vectors, how does the extent of hyporheic exchange change during seasonal baseflow recession?
We will address these questions by combining field methods (water table measurements, stream tracer experiments, electrical resistivity surveys), groundwater flow and transport modeling, stream solute transport modeling, and integrated analyses of tracer data and geophysical surveys of stream tracer distribution in the subsurface.
We pose the following research questions:
1) How do the relative magnitudes of down-valley and cross-valley vectors of riparian subsurface flow change throughout seasonal baseflow recession?
2) How are these changes controlled by valley-scale morphology and gradient?
3) How spatially consistent (at the reach scale) are the patterns of down-valley and cross-valley vectors of flow?
4) In response to seasonal changes in relative magnitudes of down-valley and cross-valley flow vectors, how does the extent of hyporheic exchange change during seasonal baseflow recession?
We will address these questions by combining field methods (water table measurements, stream tracer experiments, electrical resistivity surveys), groundwater flow and transport modeling, stream solute transport modeling, and integrated analyses of tracer data and geophysical surveys of stream tracer distribution in the subsurface.
Location: Our
field sites are within Stone Valley, PA, and the HJ Andrews
Experimental Forest, Oregon.
Project
Links: (links will be
come live as we generate these products)
- Project Summary
- Data Archive
- Methods Archive
- Report Archive
- Image Archive
- Media Archive
- Notes Archive (password protected)
Expected differences in patterns of cross-valley (CV) and down-valley (DV) flow vectors (q) in narrow, steep valleys and wide, gradually sloped valleys.
