APPENDIX B 

 GLOSSARY 



abandoned channel — A channel that was once an active or high-water chan- 

 nel, but currently flows only during infrequent floods. 



active channel — A channel that contains flowing water during the ice-free 

 season. 



active floodplain — The portion of a floodplain that is flooded frequently; 

 it contains flowing channels, high-water channels, and adjacent bars, 

 usually containing little or no vegetation. 



aesthetics — An enjoyable sensation or a pleasurable state of mind, which 

 has been instigated by the stimulus of an outside object, or it may 

 be viewed as including action which will achieve the state of mind de- 

 sired. This concept has a basic psychological element of individual 

 learned response and a basic social element of conditioned social atti- 

 tudes. Also, there can be ecological conditioning experience because 

 the physical environment also affects the learning process of attitudes. 



algae — Primitive plants, one or many-celled, usually aquatic and capable 

 of elaborating the foodstuffs by photosynthesis. 



aliquot — A portion of a gravel removal area that is worked independently, 

 often sequentially, from the other portions of the area. 



alluvial river — A river which has formed its channel by the process of 



aggradation, and the sediment by which it carries (except for the wash 

 load) is similar to that in the bed. 



arctic — The north polar region bounded on the south by the boreal forest. 



armor layer — A layer of sediment that is coarse relative to the material 

 underlying it and is erosion resistant to frequently occurring floods; 

 it may form naturally by the erosion of finer sediment, leaving coarser 

 sediment in place or it may be placed by man to prevent erosion. 



auf ei s — An ice feature that is formed by water overflowing onto a surface, 

 such as river ice or gravel deposits, and freezing, with subsequent 

 layers formed by water overflowing onto the ice surface itself and 

 f reez i ng . 



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