Flow regimes in coastal California steelhead trout streams: Spatiotemporal patterns in magnitude, duration and timing

• DOI: 10.1002/rra.3571
• Publication Date: 2019-12-26T00:35:23Z
• Authors: Jason L. Hwan; Robert W. Holmes
• Keywords: Riffle; Temporal scales; Flow conditions; Biota

Abstract The magnitude, timing and duration of precipitation events can vary considerably across spatial temporal scales. In lotic ecosystems, such differences in patterns strongly influence water availability, which turn affects the population dynamics stream biota. Connectivity flow thresholds were developed for movement juvenile steelhead trout using hydraulic modelling 37 coastal California streams. Spatial spatiotemporal flows meeting threshold levels analysed long‐term gaging data. Flow through riffle sites varied from 0.06 (San Luisito Creek, Elder Creek) to 0.82 (Redwood cms (cubic meters per second). increased positively with mean bankfull width, indicating that more is required fish wider Precipitation was a dominant driver duration, longer wetter regions state when compared drier regions. On rising limb hydrograph, onset influenced by being met earlier streams narrower receding precipitation, remaining above later Based on these findings, we recommend management aquatic resources broad range objectives consider regional scales account local channel form prevailing year conditions accommodate California's wide diversity availability.