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Research Page



Research Interests:

I am interested in process geomorphology, which is the study of fluid motion, sediment transport and the resultant deposition of geomorphic features like, gravel bars and beaches. My research goal is to develop a better understanding of the links between fundamentally important geomorphic and ecosystem processes that can help guide conservation and restoration of river-lake ecosystems. This goal has lead me to investigate physical processes active in both regulated and unregulated rivers, as well as, nearshore environments of lakes and ocean coasts.



Current Research
Photo Description
Nyack River food plain
Figure 1. An example of a key hydraulic property (stream power) mapped across a portion of the Nyack flood plain by classifying multispectral imagery (1999) from on the ground measures of instream topographic and velocity profiles. Major bank erosion and subsequent channel migration (yellow dotted line Box A) occurred during May and June of 2000 and 2001. Bank erosion was also active in the area corresponding to red zones in Box B on this map underscoring the predictive power of this analysis.

Biocomplexity:

FLBS colleagues recently received a NSF grant (2001-2004) titled "BIOCOMPLEXITY -DYNAMI CONTROLS ON EMERGENT PROPERTIES OF RIVER FLOOD PLAINS". A fundamental concept of this biocomplexity proposal is that alluvial floodplains are regional hotspots of biodiversity because of active landscape-forming processes that create a complex, dynamic array of resource patches and interfaces, which we refer to as the shifting habitat mosaic. This mosaic allows many species to co-exist in the floodplain landscape. Specifically, the key processes are cut and fill alluviation, channel avulsion and production and entrainment of LW (large wood). Groundwater routing through the flood plain and upwelling back to the surface mainly involves penetration of river water into zones of high hydraulic conductivity created by the legacy of channel scour and fill.

We are integrating remote sensing (Multi-spectral imagery) with in field measures of water depth, flow velocity and slope to model the spatial distribution of stream power to better determine where in the floodplain important processes like erosion and channel avulsion may occur.
Yackama River
Figure 1. A multi-spectral image showing an overlay of modeled topography (far left panel) and a comparison (middle panel) of a modeled flood discharge (dark blue) to actual flood of 1996 (light blue) based on the modeled topography and the spatial distribution of shear stress in the flood plain corresponding to the modeled flood discharge in the middle panel (far right panel).

Yakama River, Washington:

This project is funded by Bureau of Reclamation (BoR). As part of their habitat restoration plan the BoR is purchasing land in the floodplain in an attempt to allow the river to do the work of habitat restoration. We have developed a remote sensing technique to map shear stress across the floodplain to help guide that effort (Fig.1). With this technique we will be able to better identify what areas of floodplain have the potential to become re-connected to the system and allow important processes of cut and fill alluviation and channel avulsion to occur. In this way our research is helping to guide conservation and restoration of shallow water habitats in key reaches that appear to be critical for productivity of juvenile salmon and steelhead.
Jet boating on the Snake River
Figure 1. Measuring the velocity flow field with and ADP coupled to a GPS from a jet boat on the Snake River.

Snake River, Idaho:

This project is funded by Bureau of Reclamation (BoR) with the overall goal to develop biologically based system management information, which will provide a link between river system management and biological conditions on which wildlife, vegetation and other aquatic resources depend. One objective of this project is to examine the hydrologic flows necessary to maintain geomorphic function through the redistribution of bed material and link the geomorphic and hydrologic analysis to maintenance of channel and riparian habitat. To do this we measure in detail the velocity flow field with an Acoustic Doppler velocity-Profiler (ADP) coupled with a GPS (Fig. 1)

Upper Snake River Final Report -(PDF format, 9.2 MB)

Fisher Flow 1997 Animation - (Quicktime format, 8.1 MB)

Fisher Flow 2002 Animation - (Quicktime format, 6.0 MB)