Remote Mapping of River Channel Morphology March 9, 2003 Carl J. Legleiter Geography Department University of California Santa Barbara

Acknowledgements Collaborators Collaborators Dar Roberts and Tom Dunne, UCSB Dar Roberts and Tom Dunne, UCSB Mark Fonstad, Southwest Texas State University Mark Fonstad, Southwest Texas State University Andrew Marcus, University of Oregon Andrew Marcus, University of Oregon Robert Crabtree and Kerry Halligan, Yellowstone Ecological Research Center Robert Crabtree and Kerry Halligan, Yellowstone Ecological Research Center Annie Toth, Jim Rasmussen, Rob Ahl, Seth Peterson Annie Toth, Jim Rasmussen, Rob Ahl, Seth Peterson Funding agencies Funding agencies NASA Earth Observation Commercial Applications Program - Hyperspectral NASA Earth Observation Commercial Applications Program - Hyperspectral NASA Jet Propulsion Laboratory NASA Jet Propulsion Laboratory California Space Institute California Space Institute American Society for Engineering Education American Society for Engineering Education National Science Foundation National Science Foundation

Presentation outline Project rationale Project rationale Significance of river channel morphology Significance of river channel morphology Role of remote sensing Role of remote sensing Methodology Methodology Laboratory spectra / numerical simulation Laboratory spectra / numerical simulation Hyperspectral image analysis Hyperspectral image analysis Radiative transfer modeling Radiative transfer modeling Accuracy assessment / sensitivity analysis Accuracy assessment / sensitivity analysis Anticipated results Anticipated results Flexible model for estimating depth from imagery Flexible model for estimating depth from imagery Identify potential and limitations of remote approach Identify potential and limitations of remote approach Broader impacts Broader impacts Applications in geomorphology and ecology Applications in geomorphology and ecology Powerful tool for resource management Powerful tool for resource management

River channel morphology and the role of remote sensing Channel morphology Channel morphology establishes physical habitat conditions establishes physical habitat conditions influences flow processes and sediment transport influences flow processes and sediment transport responds sensitively to disturbance impacts responds sensitively to disturbance impacts requires an accurate, quantitative, and spatially explicit descriptive framework requires an accurate, quantitative, and spatially explicit descriptive framework Remote sensing Remote sensing provides expanded coverage provides expanded coverage captures spatial and temporal variations captures spatial and temporal variations allows analysis across a range of scales allows analysis across a range of scales

Spectral properties of streams: measurement and modeling Signal recorded by sensor influenced by Signal recorded by sensor influenced by water depth water depth substrate characteristics substrate characteristics suspended sediment suspended sediment surface turbulence surface turbulence viewing and illumination geometry viewing and illumination geometry Direct spectral measurements Direct spectral measurements Depth, substrate, image geometry Depth, substrate, image geometry Numerical simulation Numerical simulation Suspended sediment, specular reflectance Suspended sediment, specular reflectance

Hydraulic / hyperspectral analysis Data sources Data sources AVIRIS hyperspectral imagery AVIRIS hyperspectral imagery USGS streamflow records USGS streamflow records Theoretical basis Theoretical basis Manning’s equation Manning’s equation Q = AR 2/3 S 1/2 /n Q = AR 2/3 S 1/2 /n Radiative transfer models Radiative transfer models Solution technique Solution technique Iteratively adjust model parameters to match measured discharge Iteratively adjust model parameters to match measured discharge

Model evaluation Accuracy assessment Accuracy assessment AVIRIS scenes excluded from model-building AVIRIS scenes excluded from model-building Probe-1 hyperspectral imagery and field data from Lamar River, WY Probe-1 hyperspectral imagery and field data from Lamar River, WY Sensitivity analyses to quantify effects of Sensitivity analyses to quantify effects of suspended sediment suspended sediment substrate variability substrate variability channel complexity channel complexity sensor resolution sensor resolution Goal: identify appropriate conditions and define limitations Goal: identify appropriate conditions and define limitations

Anticipated Results Laboratory spectral library Laboratory spectral library depth, substrate, image geometry depth, substrate, image geometry Radiative transfer model for estimating depth from imagery Radiative transfer model for estimating depth from imagery flexible and physically-based flexible and physically-based Quantitative analysis of potential and limitations Quantitative analysis of potential and limitations critical assessment of the technique critical assessment of the technique Continuous bathymetric maps Continuous bathymetric maps detailed, spatially extensive representation of channel morphology detailed, spatially extensive representation of channel morphology

Applications and broader impacts Fluvial geomorphology Fluvial geomorphology process interactions across a range of scales process interactions across a range of scales Stream ecology Stream ecology spatial distribution of habitat within watersheds spatial distribution of habitat within watersheds Resource management Resource management inventory and monitoring inventory and monitoring in-stream flow requirements in-stream flow requirements stream restoration stream restoration flood hazard assessment flood hazard assessment Preservation efforts Preservation efforts maintain geomorphic, biotic, and aesthetic integrity maintain geomorphic, biotic, and aesthetic integrity

Conclusion: Remote mapping of channel morphology Rationale Rationale Ecological significance and vulnerability of streams Ecological significance and vulnerability of streams Remote sensing offers synoptic perspective Remote sensing offers synoptic perspective Methodology Methodology lab spectra lab spectra hyperspectral/hydraulic analysis hyperspectral/hydraulic analysis accuracy assessment accuracy assessment Research objectives Research objectives flexible model for estimating depth flexible model for estimating depth document potential and limitations document potential and limitations Applications Applications fluvial geomorphology fluvial geomorphology stream ecology stream ecology resource management resource management