In recent hydraulic experiments on tsunanii bore propagation, Fukui 

 et al (1963), use a modified form of Lamb's Eq. (D-6) for comparison 

 with their measurements. This modification takes the fornn 



1/2 



g(d+ H)(2d+ H) 

 2 {d+ H(l-S )) 



(D-12) 



The "disturbance" coefficient S is a resistance term which the author 

 derived experimentally for a bed roughness equivalent to a Manning's n 

 of 0.013. Derived as a function of d/(d+H), 8 was found to vary from 

 0. 83 at d = to 1. 03 for d/{d+ H) > 0. 5. 



It is convenient to render Eq. (D-12) in the alternative form 



Mh 



(1 + d/H)(l + 2d/H) 

 2 { (1 -S ) + d/H) 



1 1/2 



(D-13) 



and thence find, for the special case of interest of the propagation of 

 a bore over a dry bed (d = 0, S = 0. 83) 



1. 73 



gH 



(D-14) 



A more recent series of experiments on tsunami surges has been 

 made by Cross (1966, 1967), fronn whose work Fig. 99 (in the text) has 

 been reproduced. Cross reviews soine of the features we have discussed 

 above and in his more complete report (Cross, 1966) discusses the work 

 of Dressier (195Z) and of Whithani (1955) relative to the dam-break problem. 

 These authors results are quite similar in showing that the factor u/ ^ gH 

 tends to decrease rather rapidly from the value 2. for a frictionless 



D-5 



