Geomorphic survey of eastern Cascade streams before and after 1995-1996 floods

A series of cross-sectional surveys was made on streams on the Wenatchee Na tional Forest prior to flooding during winter 1995-1996. Resurveys were mad e on 18 stream reaches. Physical attributes of stream channels were measure d and flood responses were assessed across a range of stream types and land system units. Changes in cross-sectional area, width and depth were measur ed. Lateral migration was measured. Aggradation and degradation of thalweg depth were surveyed. There was high correlation between geomorphologic chan nel characteristics and channel response. Degree of entrenchment and channe l slope were highly correlated with increases in channel depth and channel scour. Slightly entrenched channels had higher lateral migration rates. A h ierarchical framework for ecological stratification offered geomorphic expl anation for channel features that correlate with channel response to extrem e flood events. Published by Elsevier Science B.V.