FLORIDA GEOLOGICAL SURVEY


 0 10 20 30 40 50 60 70
 Water loss, L = P R, in inches
Figure 46. Relation of effective annual rainfall and annual water loss,
 Withlacoochee River at Trilby, 1931-61.

natural water loss for the Withlacoochee River at Trilby is shown
to be 45 inches. This figure compares favorably with the 48 inches
of average water loss shown for 720F., the mean annual
temperature for the area, in figure 7.
 Figure 47 shows the plotted yearly figures of rainfall and
runoff for the Trilby station and an average curve. The average
cu;ve was determined by using the curve in figure 46 and plotting
the departures of the potential water-loss curve from the limiting
curve(P. = L).