50 ifO 30 



Exceedence Frequency Per 100 

 20 10 5 1. . 



Year 



3 



0.1 







o.c 





! 1 i ■ ■ i i 









e: 







1 







1 



ill III 









! 1 





ii 









J-- - 



r |ii^i!i:"x 













II 



T 







i 























_ 



i.c IE 1 



T i ! Ill ^ 











.J-- 





t 









^C r: • : : ■■::-•■■ 



... J , ,- y^ 



f^^; - , 



y^^ 



-1- -r- — 1 







: .XT : 









-nj_l 1 : 



.£ :.:::: 



; ^ ■- 



1 



—' — :;_ 



-^--; I' -' -H"-T~^ 



qri-.: : : . : : : ,;-.:: 



/* 



■ 



=ir=: ;;_ 



* 1 



•^mMM 



mmwM 





.: : l^ J ^ - 



_^--:. 







MM-mm 



..u^lSr 



' — -i"-- 



1 i 

 1 



: 





■'>M^^§ 



^-- 1:.: ;:y ;,:;-; 



I r_J:;J_: 



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-^-- p: 



'--- '■ -----r-^ 





IlipM^J^ 



= 



=^ 



— li ; M 





1 



1 



-^^^ — J 



• -■3 - — •-__ : 



™l 



= 



^ 





4- 



FT 



1 



= 



= 





+ "H 





^' 

















































1 



































/ — i: 



























.2 ^ 



j~ l ± 



















1 1 







_ 

































_ ^ 



















r 











" 7t" " 





























^1 



























i 































J 





























f 





























t 























































1 



f 

























. 



H is the actual surge height 



Hg is a Beta Hurricane surge height with parameters 

 Large Radius and Mediiim Forward Speed. 



Figiire h. Initial Generalized Surge Frequency Texas Hurricanes 



Curve 1 on Figure 5 shows the surge frequency at Galveston derived 

 from the initial generalized frequency curve, and curve 2 shows surge 

 frequency based only on those hurricanes affecting Galveston. Five 

 hurricanes that crossed the Louisiana Coast and 12 that crossed the Texas 

 Coast were used in the verification analysis. Equations (2) and (3) were 

 used in estimating the surge heights at Galveston when recorded surge 

 heights were unavailable. It is seen by comparing curves 1 and 2 on 

 Figure 5 that for higher surges (greater than 6 feet above MSL) the 

 maximum departure between the two curves is about 1 foot. Thus the two 

 entirely different methods for deriving open-coast surge frequency are 

 in reasonable agreement for the higher surges. Surges in the lower range. 

 however, show considerable departure but this will be of no consequence 

 because the surges in this range will be corrected in the final analysis 

 to include nonhurricane surges. Adjustments made for the lower surges 

 will be covered in subsequent paragraphs. 



12 



