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will suffice for the following use/application Balsillie, 1998). Here, however, beach width examples. is used since, compared to the others, it offers the largest range in magnitudes. Seasonal Beach Changes
Let us investigate such seasonal changes Beach changes due to extreme impacts for two localities with identical profile from storms and hurricanes are considered to conditions and average seasonal MSL more nearly represent isolated events. There shoreline variations, but different MHW are, however, beach changes that are more datums. First, however, we need some nearly episodic or cyclic. For instance, representative foreshore slope data. From systematic beach changes through an Table 3, let us select the average foreshore astronomical tidal cycle (e.g., Strahler, 1964; slope of tan afs = 0.085 to represent a Sonu and Russell, 1966; Schwartz, 1967), winter foreshore slope and a maximum of cut and fill associated with spring and neap tan afs = 0.2 (.e., 0.085 + 3 standard tides (e.g., Shepard and LaFond, 1940; deviations) to represent a summer foreshore Inman and Filloux, 1960), and effects of sea slope. The two cases, each with a summer breeze (e.g., Inman and Filloux, 1960; and winter profile are illustrated in Figure 6. Pritchett, 1976), are well known. Of the possible cyclic occurrences, however, Like Figure 4, Figure 6 is a simplification, perhaps the most pronounced
is that occurring on the
I I I T V I I f I I I l l
seasonal scale. Using the .. above prescribed rules, the +4 following scenarios can be +2: SMAMER / suggested. During the winter a a = o us season, when incident storm -2 wave activity is most active, 4 high, steep waves result in +4 e6.9 shoreline recession. Normally, the berm is eroded and a +2
0W IN T ER .' MS t. gentle foreshore slope is 2 tan a = 0.0 5 produced. Sand removed C from the beach is stored ; 4 MHW+t5. MSLC t offshore in one or more  MS longshore bars. During the arm summerseasonsmallerwaves j +4 low with smaller wave steepness +2 SUMMER values transport the sand 0l tan a. .2 stored in longshore bars back 2 -4: 67.1 ft.I onshore, resulting in a wider beach berm and steeper gem/ foreshore. +2 WINTE us
0 tan af = 0.0 85Seasonal beach changes -2
have been described in terms 4 CASE 40 ft. of sand volume changes, MHW = +4.0 ft. MSL contour elevation changes, 12 so 4o ' -40 -6o and horizontal shoreline shift Distance (feet) or beach width changes (see Figure 6. Seasonal hodrizontal shorerne shift analysis.
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