where 



Q = total transport in pounds per year 



C = Bagnold constant 



/ = length of reach in feet perpendicular to direction 

 of wind considered 



d = average grain diameter of sand considered (d^Q mm) 



D = average grain diameter of standard 0.25 mm sand 



y = specific weight of air = (0.076 lbs/ft"^) 



U^, = shear velocity in ft/sec 



T = duration of wind in seconds per year 



g = acceleration due to gravity = 32.2 ft/sec 



Now substituting the values of y i g> and choosing C =1.8, since the sand 

 considered has a natural grading, we obtain from Equation (11) 



Q = 1.8 • X • t • 3.6 ■ 10^ IT • 9.1^11 ■ U^3 



Vd 32.2 



Q = 15.20 t • i ^ U* in pounds per year (12) 

 D 



where t is in hours per year. 



Wind Duration per Year "t" . Duration in hours of winds of various 

 speeds from various directions was collected from data obtained from the 

 Pacific Marine Station, Dillon Beach, California. Data were available 

 for the period September 1, 1962 to August 31, 1963 which gave us one 

 year of records. These data are shown in Figure. 3. In Table 2 these 

 data are summarized for calculation purposes. Wind speeds below 10 mph 

 were considered calm, since their contribution to transport may be 

 neglected. The uneven values of wind speeds shown in both Figure 3 and 

 Table 2 resulted from the reduction of the wind data from the anemometer 

 chart and the calibration curve of the anemometer. Total number of hours 

 contributing to transport (greater than 10 mph) was 1135 hours; calm hours 

 3555 and for 4070 hours tne anemometer was inoperative. 



