IV. COMPARISON OF RESULTS 



The changes in each reach have been discussed in the preceding section. More 

 detail vras given to reaches A and B because of the greater number of photo sets 

 examined. In this section, tKe results are compared between reaches and to the 

 results of other investigators. In addition, the relationships between the causa- 

 tive factors of bluff recession and the measured rates are examined along with a 

 possible explanation of the effect of the reach B seawall. 



1. Comparison Between Reaches . 



Cumulative amounts of bluff recession and shoreline change for each reach, 

 as given in Tables 5 to 9, are plotted in Figure 33. The data for four common 

 periods are tabulated in Table 10 for a better comparison of the five reaches. 

 Although reach A had the highest overall bluff recession and bluff recession 

 rate, reach D had the highest rate for any single period, losing 7.1 meters 

 between November 1972 and October 1973. Volumetric losses were definitely 

 larger in reaches A and B due to the greater bluff heights. 



REACH A 



1971 



1972 



1973 



1974 



rigure 33. Cumulative bluff recession and shoreline chanj 

 for each reach (data from Tables 6 to 9) . 

 Shaded areas indicate periods of ice cover. 



48 



