Table 4 



Conditions for the Formation of Tombolos 



Condition 



Comments 



Reference 



LJy > 2.0 





SPM (1984) 



LJy > 2.0 



Double tombolo 



Gourlay (1981) 



LJy > 0.67 to 1.0 



Tombolo (shallow water) 



Gourlay (1981) 



£ s /y > 2.5 



Periodic tombolo 



Ahrens and Cox (1990) 



L s ly > 1 .5 to 2.0 



Tombolo 



Dally and Pope (1986) 



LJy> 1.5 



Tombolo (multiple breakwaters) 



Dally and Pope (1986) 



LJy > 1.0 



Tombolo (single breakwater) 



Suh and Dalrymple (1987) 



LJv > 2 blL s 



Tombolo (multiple breakwaters) 



Sun and Dalrymple (1987) 



Table 5 



Conditions for the Formation of Salients 



Condition 



Comments 



Reference 



LJy < 1 .0 



No tombolo 



SPM (1984) 



ij/y < 0.4 to 0.5 



Salient 



Gourlay (1981) 



LJy = 0.5 to 0.67 



Salient 



Dally and Pope (1986) 



LJy < 1.0 



No tombolo (single breakwater) 



Suh and Dalrymple (1987) 



LJy < 2 b/L s 



No tombolo (multiple breakwaters) 



Suh and Dalrymple (1987) 



LJy < 1 .5 



Well-developed salient 



Ahrens and Cox (1990) 



ij/y < 0.8 to 1 .5 



Subdued salient 



Ahrens and Cox (1990) 



Table 6 



Conditions for Minimal Shoreline Response 



Condition 



Comments 



Reference 



L s ly < 0.17 to 0.33 



No response 



Inman and Frautschy (1966) 



LJy £ 0.27 



No sinuosity 



Ahrens and Cox (1990) 



LJv <, 0.5 



No deposition 



Nir (1982) 



L,ly £ 0.125 



Uniform protection 



Dally and Pope (1986) 



LJy 5 0.17 



Minimal impact 



Noble (1978) 



40 



Chapter 2 Functional Design Guidance 



