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Tuesday, May 27, 2008
363
Comparison of stream nitrate uptake and geomorphic complexity in agricultural and urban settings
Daniel W. Baker, Jennifer Mueller Price, and Brian P. Bledsoe. Civil and Environmental Engineering, Colorado State University, Fort Collins, CO 80523
To explore the relationship between nitrate uptake and related components of geomorphic complexity, we surveyed three unique segments on each of two streams, one a Colorado Front Range urban stream and the other in a mountainous agricultural region in north central Colorado. Each study segment was chosen for its distinctive geomorphic setting and historical human modification; the urban stream showing various levels of stabilization and planform alteration, and the agricultural stream subject to variable cattle grazing practices and channel slope. All segments were surveyed using a detailed protocol for characterizing physical complexity in terms of the spatial distribution of habitat units with distinct combinations of geomorphic, substrate, and hydraulic attributes. To model nitrate uptake, we used a transport-based approach for time-series data collected at both ends of each reach. We discuss variability in uptake results with respect to channel complexity and other contributing factors.
Web Page: Nutrient uptake, geomorphic complexity, biogeochemistry