Two-dimensional modelling of habitat suitability as a function of discharge on two Colorado rivers
Version of Record online: 3 AUG 2005
Copyright © 2005 John Wiley & Sons, Ltd.
River Research and Applications
Volume 21, Issue 10, pages 1061–1074, December 2005
How to Cite
Stewart, G., Anderson, R. and Wohl, E. (2005), Two-dimensional modelling of habitat suitability as a function of discharge on two Colorado rivers. River Res. Applic., 21: 1061–1074. doi: 10.1002/rra.868
- Issue online: 25 NOV 2005
- Version of Record online: 3 AUG 2005
- Manuscript Accepted: 12 JAN 2005
- Manuscript Revised: 15 DEC 2004
- Manuscript Received: 20 MAY 2004
- instream flows;
- two-dimensional modelling
The quantity of water that should be retained in streams and rivers for the benefit of fish during periods of water scarcity is a question of considerable interest to river managers and biologists. Although instream flow methodologies have existed since the 1970s, no single method has been widely accepted for use on large warm-water rivers because of their high species richness and generalized fish habitat use patterns. In this paper, we present an approach similar to instream flow incremental methodology, but which uses two-dimensional flow models and biomass estimates derived from multiple sites on two Colorado rivers for predicting the effect of discharge on adult standing stocks of two native fish species. Suitability criteria are developed for bluehead and flannelmouth sucker (Catostomus discobolus and C. latipinnis) by comparing adult biomass in individual meso-habitat units with modelled depths and velocities. We find that roundtail chub (Gila robusta) biomass is not correlated with depth and velocity, but appears to be positively associated with indices of habitat heterogeneity. Species biomass and total usable habitat area are predicted as a function of discharge for each site and data show good correlation between predicted and measured biomass. Results suggest that the Colorado and Yampa Rivers have similar potential for native fish biomass, but low summer discharges limit native fish biomass on the Yampa River. Copyright © 2005 John Wiley & Sons, Ltd.