172 
PACIFIC SCIENCE, Vol. XXII, April 1968 
TABLE 14 
Beach Sand Reservoirs, Miscellaneous 
Coastal Zones, Hawaii 
SUMMATION 
AVERAGE 
OF BEACH 
SAND 
LENGTHS 
VOLUMEf 
COASTAL ZONE* 
(yards) 
10 3 yd 3 
Upolu-Pololu 
100 
12.0 
Pololu 
525 
63.0 
Pololu— Waipio 
515 
61.8 
Hilo-Kaimu 
300 
18.0 
Kaimu-Punaluu 
400 
16.0 
Punaluu-Hookena 
1000 
120.0 
Hookena-Napoopoo 
Kealakekua- 
30 
2.4 
Disappearing Sands 
Disappearing Sands- 
200 
24.0 
Hapuna 
5500 
825.0 
Hapuna-Kawaihae 
500 
75.0 
* Listed clockwise from northern coast of island, 
f Volumes obtained from a single set of profiles in 1963, 
supplemented by aerial photographs and maps. 
On Maui, rates of change are low, measured 
in a few cubic yards of sand per linear yard of 
beach per month (Table 20). Whereas most 
of the other Hawaiian islands are directly ex- 
posed to the waves generated by the southerly 
and westerly winds, Maui is protected in that 
quarter by the islands of Kahoolawe and Lanai, 
and a little to the northwest, by Molokai. 
Consequently, the refraction of waves around 
these obstacles, in addition to the direction of 
wave approach, plays an important part in de- 
termining the amount of energy reaching the 
coast. Because of this consideration the fluctu- 
ations of the various beach sand reservoirs do 
not show any simple relationship to the gross 
meteorological spectrum detailed in Figure 3. 
Relationships undoubtedly exist — since the sea- 
sonal volumes of the total beach reservoir show 
marked fluctuations, accreting during the winter 
storm and subsequently eroding under north- 
westerly winds and waves (Fig. 4) — but the 
exact nature of this fluctuation is not clear. 
On Hawaii, rates are extremely low with the 
exception of Hapuna and Disappearing Sands 
(Table 21). But although the data are scat- 
tered and the total sand reservoir is low (lowest 
of all the islands) it is still possible to discern 
a pattern of behavior — similar to that for the 
western beaches of Oahu and Kauai — for Ha- 
puna, Kawaihae, Kailua, and other western 
beaches. On the other hand during the winter 
storms of 1962-63, Waipio Beach accreted at 
the rate of about 9 cubic yards of sand per 
linear yard of beach per month, and, with 
cessation of the westerly winds and the com- 
z 30 • 
o 
LjJ 
a. lo- 
co 
< 0- 
Q 
42- 
maximum fastest mile , m.p.h. 
30 22 
18 
O 
19 
26 
19 
16 
Z CD 
< UJ 
-> u. 
CK £T >- 
< OL < 
5 < 5 
Z _J 
“3 -3 
1962 
1963 
Fig. 3- Dominant winds, 1962-63. Upper , number of days per month that winds blew from the northern, 
eastern, and southern quadrants. Lower, number of days per month that winds blew from the southern 
and western quadrants. 
