Summary of Conclusions 



19. The Sequoia methodology provides a 

 straight-forward, simple accounting 

 system for evaluating watershed dis- 

 turbance related to water yield and a 

 relative numerical rating. (*H) 



20. Application of the Sequoia method in 

 the Swan River Drainage demonstrated 

 that a few analysis areas had an unusu- 

 ally high concentration of activities. 

 (*H) 



The Sequoia method results generally 

 agreed with estimates of cumulative 

 effects provided by other models. (*H) 

 Watershed erosion risk analysis may 

 provide resource managers with a pow- 

 erful tool to assist in land-use decision 

 making. In addition, Geographic Infor- 

 mation Systems allow the correlation 

 of land cover and topographic informa- 

 tion such as terrain configuration and 

 drainage networks, thus making GIS 

 useful in assessing the potential effects 

 of land-use activities on water re- 

 sources. (*I) 



21 



22. 



23. There was a statistically significant 

 correlation between the change in Chan- 

 nel Stability Rating (CSR) and H^OY 

 water yield increase. Sequoia Cumula- 

 tive Runoff Area (CRA), WATSED 

 water yield increase, and WATSED 

 water yieldincrease — 75percentpeak 

 flow duration. (*J) 



24. WATSED equivalent clearcut acreage 

 was positively correlated with sus- 

 pended sediment. (*J) 



25 . Three of the 30 watersheds selected for 

 the correlation review were above the 

 thresholds for both Sequoia and H^OY, 

 while 3 other watersheds with rela- 

 tively high values for Sequoia had rela- 

 tively low to moderate values for H^OY. 

 (*H and *J) 



26. The correlation between the measured 



suspended sediment values and the pre- 

 dicted WATSED sediment values was 

 highly significant. (*J) 



Flathead Basin Cooperative Program Final Report 



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