between stations 1 and 13 was also retreating despite a series of new sandbag 

 groins. Probable explanations for the dramatic changes of the dime and for 

 the downdrift cut are given in Section IV, 4. 



Overall rates of bluff and shoreline change for the full period of study 

 are shown in Figure 19. Data measured from the air photos are summarized in 

 Table 6. The table is based on sin^jle averaging of all the stations in reach 

 B and does not separate the protected and unprotected sections of shoreline. 



Table 



6. 



Summary of bluff 



, shore, an 



d beach data for reach 



B (54 stations). 



Date 





Bluff 



recession 





Shorel 



ine chang 





Beach width'. J 



Period 

 length 





Rate 







Max. 





Rate 







Max. 









Change | 







(m) 



(ni/yr) 



(m/yr) 



(in/yr) 



(m) 



(m/yr) 



(i»/yr) 



(m/yr) 



(m) 



(ra) 



(in) ; 



(mo) 



19 Nov. 



1970 



















6.2 



5.7 











1.8 



4.3 



4.9 



20.5 



1.9 



4.5 



8.6 



19.5 









5 



15 Apr. 



1971 



















7.6 



4.2 



1.4 









1.1 



1.8 



2.7 



10.5 



3.7 



6.3 



10.1 



38.1 









7 



16 Nov. 



1971 



















10.6 



5.8 



3.0 









2.8 



6.8 



7.0 



29.3 



-8.4 



-20.2 



15.2 



-70.0 









5 



18 Apr. 



1972 



















6.7 



5.0 



-3.9 









2.4 



4.1 



4.0 



14.1 



0.4 



0.6 



7.9 



-29.0 • 









7 



16 Nov. 



1972 



















8.7 



5.5 



2.0 









3.4 



10.1 



11.4 



43.0 



1.6 



4.7 



25.5 



-63.6 









4 



20 Mar. 



1973 



















12.1 



6.1 



3.4 









1.5 



2.3 



3.1 



13.7 



-2.3 



-3.5 



10.5 



-30.7 









8 



20 Nov. 



1973 



















10.7 



6.9 



-1.4 









2.0 



4.0 



4.2 



15.2 



-3.0 



-5,9 



10.5 



-32.8 









6 



20 May 



1974 



















9.7 



4.7 



-1.0 









1.9 



3.9 



4.3 



18.3 



-2.6 



-5.3 



6.7 



-17.7 









6 



25 Nov. 



1974 



















8.2 



4.4 



-1.5 





19 Nov. 



1970 



















6.2 



5.7 











2.9 



2.9 



3.1 



13.7 



5.6 



5.6 



7.3 



25.8 









12 



16 Nov. 



1971 



















10.6 



5.8 



4.4 









S.2 



5.2 



4.4 



19.2 



-8.0 



-8.0 



8.4 



-32.8 









12 



16 Nov. 



1972 



















8.7 



5.5 



-1.9 









4.9 



4.9 



5.1 



17.1 



-0.7 



-0.7 



9.2 



-27.4 









12 



20 Nov. 



1973 



















10.7 



6.9 



2.0 









3.9 



3.9 



3.6 



14.6 



-5.6 



-5.6 



6.2 



-18.9 









12 



23 Nov. 



1974 



















8.2 



4.4 -2.5 j 





19 Nov. 



1970 

























to 





16.9 



4.2 



2.6 



11.9 



-8.9 



-2.2 



2.2 



-7.1 







48 



' 23 Nov. 



1974 

























'Beach width adjiisted to lake level (176.79 meters, IGLD). 



4. Reach C. 



Reach C extends for 1.52 kilometers southward from the last cluster of 

 homes near the Grand Mere Lakes (Fig. 20). No houses are within the reach. 

 The geomorphology of reach C differs from reaches A and B because of a low 

 foredune (Fig. 21) which fronts and protects a high, well-vegetated dune 

 ridge. 



To keep definitions consistent, the term bluff line used in this discus- 

 sion refers to the active edge of the foredune system. The bluff line could 

 be determined by stereoscopic viewing but identification was more difficult 

 than the bluff line in reaches A and B. Because of the lack of cultural fea- 

 tures, it was also difficult to establish reference points and to match suc- 

 cessive air photos. 



Only reach C of the five reaches showed any lakeward movement of the bluff 

 line due to foredune accretion. All of the accretion occurred south of the bend 

 in the orientation of the shoreline between stations 20 and 30 (see Fig. 20) . 



34 



