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<br />I <br /> <br />I <br /> <br />Stream Type ST-3a <br /> <br />I <br />I <br />I <br /> <br />General Description: Meandering channel pattern with mostly suspended sediment transport. <br />Characteristics of this stream type is a uniform width channel with regular meanders that are well <br />incised. Point bars are small and uniform. <br /> <br />Comment: River meanders are the result of secondary currents that exist in channels and are <br />most pronounced at bends. Meanders are the result of higher power, and meandering streams <br />actively migrate as the result of selective bank erosion and point bar formation. Irregularities in <br />the natural terrain and sedimentation (formation of bars) strongly affect the meandering course. <br />Meander sinuosity and section depth increase with high silt-day contents in the perimeter <br />sediments. <br /> <br />I <br /> <br />Relative Stability: Stable to Moderately Unstable <br />Uncertainty: Moderate, meander migration and neck cutoff <br />Sinuosity, P: > 1.25 <br />Stream Type ST.3b <br /> <br />I <br /> <br />I <br />I <br /> <br />General Description: Meandering channel pattern with mixed contact and suspended <br />sediment transport. This stream type has a lower silt-clay content, resulting in a shallower <br />channel section and a additional width at channel bends. <br /> <br />I <br /> <br />Comment: This stream type is the lower silt-clay content variation of stream type ST-3a. <br />Point bars are distinct features of the stream pattern, but chute development is rare. <br /> <br />I <br />I <br /> <br />Relative Stability: Stable to Moderately Unstable <br />Uncertainty: Moderate, meander migration and neck cutoff <br />Sinuosity, P: 1.05 - 1.26 <br />Stream Type ST-4 <br /> <br />I <br /> <br />General Description: Meandering channel pattern with mostly contact sediment transport. <br />This stream type is more irregular in its width, islands and chutes are more likely to occur. Two <br />meandering frequencies may occur together leading to a different sinuosity at low water. <br /> <br />I <br /> <br />I <br /> <br />Comment: This stream type is the near limit of stability for the meandering channel form. <br />Medial bars and chutes are more frequent. Channel incisement increases with higher silt-day <br />content, channels are wider and shallower at lower silt-day content. Two meander wavelengths <br />can occur in the same channel with a low-flow meander occurring within main channel. Point <br />bars are the primary feature of the stream pattern, and chute development is common. <br /> <br />I <br />I <br />I <br />I <br /> <br />Relative Stability: Moderate to Low <br />Uncertainty: Moderate, meander migration and chute cutoff <br />Sinuosity, P: > 1.25 <br /> <br />6 <br />