SUMMARY AND CONCLUSIONS 



Various physical characteristics of arctic and subarctic rivers were 

 affected by gravel removal operations. These characteristics were divided 

 into five categories: 



1. Channel configuration and process, 



2. Hydrau I ics , 



3. Sedi mentat i on , 



4. Ice characteristics, and 



5. Hydrology. 



One or more characteristics from these categories were observed to have 

 changed as a result of removing gravel from the 25 floodplain study sites. 



CHANNEL CONFIGURATION AND PROCESS 



Channel configuration and process characteristics that changed as 

 a result of gravel removal operations included braiding characteristics, 

 such as increase in the number of channels and decrease in lateral stabil- 

 ity of the channels, and the potential for diversion of flow through the 

 gravel removal area. The greatest changes in braiding characteristics 

 occurred at 10 study sites and resulted from gravel removal operations 

 that disturbed the bars adjacent to active channels or that diverted flow 

 through the material site. Flow diversion through the mined site resulted 

 from having insufficient buffers or no buffers at all. Gravel removal 

 operations caused flow diversion or a high potential for flow diversion 

 at 12 of the 25 study sites. 



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