176 
A NEW METHOD OF ESTIMATING STREAM-FLOW 
The constants (85) may be converted into percentages in the same manner and 
by the same conversion factors used on the normal-flow equations. In Table 48 
the process of conversion to percentages is similar to that previously given. 
In Table 48, column 2 shows the constants (85); column 3 the conversion 
factor for converting the stream-flow of Stream B in c.f.s. to units of 0.01 inch or 
0.1 inch of depth per day on Watershed B; column 4, the per cent of that part of 
the change in storage above the ground surface on the current day which reaches 
the stream by surface travel on each day of each time interval involved in the defini- 
tions of the r/s. 1 Thus 1.67 per cent of the change in storage above the ground 
surface on the current day is delivered to Stream B by surface travel on that day, 
or 0th day; 1.73 per cent of the change the current day is delivered to the stream 
the following day 1 ; . . . 0.282 per cent of the change in storage above ground the 
current day is delivered on each of the seventeenth to thirty-second days (inclusive) 
Table 48 — Conversion of flood-flow constants to percentages, Stream B 
Constant 
Absolute value 
of constant 
from (85) 
Factor to con- 
vert col. 2 to 
percentage of 
change in stor- 
age which is 
delivered in 
one day 
Per cent of 
change in stor- 
age which 
reaches stream 
in one day 1 
(col. 2Xcol. 3) 
No. of days or 
time interval 
involved in 
each constant 
Total per cent 
of change in 
storage above 
ground surface 
on current day 
which is de- 
livered to 
Stream B in 
each time 
interval 1 
Col. 4 smoothed 
once by means 
of 3 
R'n 
R'n 
R'n 
R'n 
R'/t 
R'/n 
R'n 
+ 1.41 
+ 1.45 
+ 1.44 
+ 1.95 
+ 15.31 
+ 7.02 
+ 2.37 
1.19 
1.19 
1.19 
1.19 
0.119 
0.119 
0.119 
1.67 
1.73 
1.71 
2.32 
1.82 
0.835 
0.282 
Totals 
1 
1 
1 
2 
4 
8 
16 
33 days 
1.67 
1.73 
1.71 
4.64 
7.28 
6.68 
4.51 
1.67 
1.70 
1.92 
1.95 
1.66 
0.98 
0.37 
28.22 p. ct. 
29.6 p. ct. 
following. 1 The product of each quantity in column 4 by the time interval in 
column 5 gives the total percentage of the change in storage above ground surface 
on the current day which is delivered to the stream in the whole of the time interval 
in question. 1 Thus, during the ninth to sixteenth days, inclusive, after the change 
in storage occurs, a total of 6.68 per cent (col. 6, line 6) of it is delivered over 
the surface of the ground to Stream B. 1 Totaling all the quantities in column 6, 
there is obtained 28.2 per cent as the total part of the change in storage on the 
current day which is delivered to Stream B by surface travel during a period of 33 
days following (and including) the current day. 1 
The percentages shown in column 4 were smoothed once by taking successive 
means of three values in that column, and assuming R' /8 , the next constant after 
R' , 7 , zero. The results of this smoothing is shown in column 7, with the total of 
29.6 per cent instead of 28.2 per cent as the total part of the current day change in 
storage reaching the stream in 33 days. 1 
1 Assuming the water table to be at the level of the ground surface on each day of the 32-day period after the 
current day. 
