Table 9 



3-D COSMOS Modeling, St. Joseph Harbor, Michigan^ 



ProfHe 



Actual Water Level 



dgg = 0.2 mm 



Marker Depth = -2.5 m 



Actual Water Level 



dgQ = 2.0 mm 



Marker Depth = -2.5 m 



High Water Level 



dgQ = 0.2 mm 



Marker Depth = -2.5 m 



Actual Water Level 



dgo = 2.0 mm 



Marker Depth = -0.5 m 



Pre-fill A 

 2-NOV-91 



Pre-fill B 

 14-Jan-92 



Pre-fill C 

 24-Jan-92 



Pre-fill G 

 2-NOV-91 



Pre-fill H 

 14-Jan-92 



Pre-fill 1 

 2-NOV-91 



Pre-fill J 

 14-Jan-92 



Pre-fill K 

 14-Jan-92 



Post-fill L 

 14-Jan-92 



8 



16,236 



-76,181 



-42,246 



2,556 



-15,694 



22,307 



-83,340 



-14,264 



-13,463 



9 



14,334 



-65,821 



-33,298 



12.549 



-16,434 



25,198 



-71,653 



-17,204 



-17,076 



9a 



34,721 



-76,438 



-17,188 



5,959 



-16,265 



51,798 



-103,042 



-16,241 



-17,712 



10 



36,180 



-84,673 



-19,024 



5,930 



-17,549 



44,014 



-99,501 



-14,849 



-15,446 



11 



44,404 



-76,167 



-15,055 



6,360 



-15,398 



44,273 



-93,430 



-18,122 



-19,778 



12 



29,832 



-108,416 



-37,910 



4,638 



■19,803 



32,404 



-117,843 



-17,659 



-18,086 



14 



21,790 



-74,825 



-27,581 



3,450 



-14,978 



13,913 



-61,701 



-14,547 



-14,551 



17 



30,018 



-90,539 



-27,761 



4,870 



-17,416 



25,109 



-87,122 



-17,262 



-17,262 



20 



23,346 



-73,101 



-22,640 



3,681 



-13,837 



14,834 



-64,358 



-12,934 



-12,934 



22 



21,354 



-58,739 



-13,839 



3,584 



-11,519 



11,957 



-50,652 



-12,177 



-12,177 



23 



30,297 



-68,254 



-16,223 



4,679 



-13,076 



27,475 



-67,874 



-14,005 



-14,005 



^ Negative is southward for 3-D analyses. 



Runs D to F (post beachflll series) 



The three initial runs were repeated with Lines R9 to Rll augmented with 

 50 m /m of fine sand (0.2 mm) beach nourishment. This represents a low to 

 average level of beach nourishment with a total volume of about 50,000 m 

 extending from about 2.4 m above datum to 1.2 m below datum. The results 

 generally featured very little change in the predicted alongshore transport rates 

 compared to the initial prefill series. It may be recalled that the orientation of 

 the nearshore contours in the numerical model are established based on the 

 2.5-m contour (i.e., the "marker depth"). Therefore, since the beach nourish- 

 ment only extends down to a depth of 1 .2 m, in the numerical model experi- 

 ments, the beach nourishment does not have an influence on the rate of 

 alongshore transport related to the orientation of the contours. Nevertheless, 

 for the NW waves of the 14 January storm, slightly greater deposition is pre- 

 dicted at Lines R12 and R14 than in the initial series. Cross-shore transport 

 processes result in rapid profile adjustment with erosion of the upper beach 

 and deposition offshore for each of the storm events. For storms with 

 NW waves, the erosion of the feeder beach does not appear to result in the 

 rapid movement of a defined pulse or slug of sediment. 



48 



Chapter 4 Analyses of Coastal Processes and Geomorphology 



