The Water Encyclopedia: Hydrologic Data and Internet Resources - Chapter 13 (end) pdf

CHAPTER 13
Constants and Conversion Factors
Pedro Fierro, Jr.
CONTENTS
Section 13A Physical Properties of Water 13-2
Section 13B Water Quality 13-6
Section 13C Length 13-7
Section 13D Area 13-8
Section 13E Volume 13-9
Section 13F Velocity 13-12
Section 13G Flow Rate 13-12
Section 13H Weight 13-14
Section 13I Pressure 13-14
Section 13J Permeability 13-15
Section 13K Power 13-16
Section 13L Temperature 13-17
13-1
q 2006 by Taylor & Francis Group, LLC
SECTION 13A PHYSICAL PROPERTIES OF WATER
Table 13A.1 Variation of Properties of Pure Water with Temperature
Temperature
(
8
C)
Temperature
(
8
F)
Density at 1
Atmosphere
(gm/cm

3
)
Dynamic
Viscosity, in
Centipoises
(10
L2
dyne-
sec/cm
2
)
Kinematic
Viscosity, in
Centistokes
(10
L2
cm
2
/sec)
Surface Tension
Against Air
(dyne/cm)
Vapor Pressure
(mm Hg)
5 41.0 0.999965 1.5188 1.5189 74.92 6.543
6 42.8 0.999941 1.4726 1.4727 74.78 7.013
7 44.6 0.999902 1.4288 1.4289 74.64 7.513
8 46.4 0.999849 1.3872 1.3874 74.50 8.045
9 48.2 0.999781 1.3476 1.3479 74.36 8.609
10 50.0 0.999700 1.3097 1.3101 74.22 9.209

11 51.8 0.999605 1.2735 1.2740 74.07 9.844
12 53.6 0.999498 1.2390 1.2396 73.93 10.518
13 55.4 0.999377 1.2061 1.2069 73.78 11.231
14 57.2 0.999244 1.1748 1.1757 73.64 11.987
15 59.0 0.999099 1.1447 1.1457 73.49 12.788
16 60.8 0.998943 1.1156 1.1168 73.34 13.634
17 62.6 0.998774 1.0875 1.0889 73.19 14.530
18 64.4 0.998595 1.0603 1.0618 73.05 15.477
19 66.2 0.998405 1.0340 1.0357 72.90 16.477
20 68.0 0.998203 1.0087 1.0105 72.75 17.535
21 69.8 0.997992 0.9843 0.9863 72.59 18.650
22 71.6 0.997770 0.9608 0.9629 72.44 19.827
23 73.4 0.997538 0.9380 0.9403 72.28 21.068
24 75.2 0.997296 0.9161 0.9186 72.13 22.377
25 77.0 0.997044 0.8949 0.8976 71.97 23.756
26 78.8 0.996783 0.8746 0.8774 71.82 25.209
27 80.6 0.996512 0.8551 0.8581 71.66 26.739
28 82.4 0.996232 0.8363 0.8395 71.50 28.349
29 84.2 0.995944 0.8181 0.8214 71.35 30.043
30 86.0 0.995646 0.8004 0.8039 71.18 31.824
31 87.8 0.995340 0.7834 0.7871 71.02
a
33.695
32 89.6 0.995025 0.7670 0.7708 70.86
a
35.663
33 91.4 0.994702 0.7511 0.7551 70.70
a
37.729
34 93.2 0.994371 0.7357 0.7399 70.53

a
39.898
35 95.0 0.99403 0.7208 0.7251 70.38 42.175
36 96.8 0.99368 0.7064 0.7109 70.21
a
44.563
37 98.6 0.99333 0.6925 0.6971 70.05
a
47.067
38 100.4 0.99296 0.6791 0.6839 69.88
a
49.692
a
Interpolated.
Source: From U.S. Department of the Interior, Bureau of Reclamation, 1977, Ground Water Manual.
THE WATER ENCYCLOPEDIA: HYDROLOGIC DATA AND INTERNET RESOURCES13-2
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Table 13A.2 Density of Water
Temperature (
8
F) Density (gm/cm
3
)
32 0.99987
35 0.99996
39.2 1.00000
40 0.99999
50 0.99975
60 0.99907
70 0.99802

80 0.99669
90 0.99510
100 0.99318
120 0.98870
140 0.98338
160 0.97729
180 0.97056
200 0.96333
212 0.95865
Note: Density of sea water: approximately 1.025 gm/cm
3
at 158C.
Table 13A.3 Weight of Water
Temperature Weight (lb/ft
3
)
32 62.416
35 62.421
39.2 62.424
40 62.423
50 62.408
60 62.366
70 62.300
80 62.217
90 62.118
100 61.998
120 61.719
140 61.386
160 61.006
180 60.586

200 60.135
212 59.843
Note: 1cu in.Z0.0360 lb; 1 cu ftZ62.4 lb; 1 galZ
8.33 lb; 1 Imperial galZ10.0 lb: Weight of sea
water: Approximately 63.93 lb/ft
3
at 158C.
Table 13A.4 Properties of Water at Various Altitudes
Altitude (Feet)
Barometric Pressure
(Inches Hg)
Atmospheric Pressure
(psia) Feet Water
K500 30.5 15.0 34.6
0 (Seasonal) 29.9 14.7 33.9
500 29.4 14.5 33.4
1000 28.9 14.2 32.8
1500 28.3 13.9 32.1
2000 27.8 13.7 31.5
4000 25.8 12.7 29.2
6000 24.0 11.8 27.2
8000 22.2 10.9 25.2
CONSTANTS AND CONVERSION FACTORS 13-3
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Table 13A.5 Properties of Water at Various Temperatures
Vapor Pressure
Temperature (
8
F) psfa Feet Water Specific Weight pcf Specific Gravity
32.0 12.7 0.20 62.42 0.9999

39.2
a
16.9 0.27 62.427 1.0000
50.0 25.6 0.41 62.41 0.9997
60.0 36.8 0.59 62.37 0.9990
70.0 52.3 0.84 62.30 0.9980
80.0 73.0 1.17 62.22 0.9966
100.0 136.0 2.19 62.00 0.9931
a
Temperature when specific gravityZ1.0000.
Source: From Soil Conservation Service, U.S. Department of Agriculture, 1971, Drainage of Agricultural Land.
Table 13A.6 Variation of Boiling Point of Water with
Elevation
Elevation, Feet above
Mean Sea Level
Boiling Point
(
8
F)
K1,000 213.8
0 212.0
1,000 210.2
2,000 208.4
3,000 206.5
4,000 204.7
5,000 202.9
6,000 201.1
7,000 199.2
8,000 197.4
9,000 195.6

10,000 193.7
11,000 191.9
12,000 190.1
13,000 188.2
14,000 186.4
Note: U.S. standard atmosphere is assumed.
Table 13A.7 Heat of Vaporization, Viscosity, Vapor Pressure, Surface Tension, and Elastic Modulus of Water
Heat
Viscosity Vapor Pressure
Temperature
(
8
F)
Vaporization
(Btu/lb)
Absolute
(lb-sec/ft
2
)
Kinematic
(ft
2
/sec) Millibars lb/in.
2
Surface Tension
(lb/ft)
Elastic
Modulus (lb/in.
2
)

32 1073 0.374!10
K4
1.93!10
K5
6.11 0.09 0.00518 287,000
40 1066 0.323 1.67 8.36 0.12 0.00514 296,000
50 1059 0.273 1.41 12.19 0.18 0.00508 305,000
60 1054 0.235 1.21 17.51 0.26 0.00504 313,000
70 1049 0.205 1.06 24.79 0.36 0.00497 319,000
80 1044 0.180 0.929 34.61 0.51 0.00492 325,000
90 1039 0.160 0.828 47.68 0.70 0.00486 329,000
100 1033 0.143 0.741 64.88 0.95 0.00479 331,000
120 1021 0.117 0.610 — 1.69 0.00466 332,000
140 1010 0.0979 0.513 — 2.89
160 999 0.0835 0.440 — 4.74
180 988 0.0726 0.385 — 7.51
200 977 0.0637 0.341 — 11.52
212 970 0.0593 0.319 — 14.70
Note: Heat of fusion at 328F: 143.5 Btu/lb.
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Table 13A.9 Velocity of Sound in Water and Sea Water
Temperature (
8
C) Pure Water (m/sec) Sea Water (m/sec)
0 1,400 1,445
10 1,445 1,485
20 1,480 1,520
30 1,505 1,545
Note: Assuming atmospheric pressure and sea water salinity of 35,000 ppm.

Source: From Berry, Bollay, and Beers, Handbook of Meteorology, McGraw-Hill,
Copyright 1945. With permission.
Table 13A.8 Thermal Conductivity of Water
Temperature
8
C(
8
F)
Cal/sec/cm
2
under
1
8
C/cm Btu/sec/ft
2
under 1
8
F/in.
0 (32) 0.00139 0.00111
4 (39.2) 0.00138 0.00110
15 (59.0) 0.00144 0.00115
20 (68.0) 0.00143 0.00114
CONSTANTS AND CONVERSION FACTORS 13-5
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SECTION 13B WATER QUALITY
Table 13B.10 Constants and Conversion Factors for Water Quality
To Convert To Multiply By
Grains per Imperial gallon Parts per million 14.3
Grains per gallon Parts per million 17.12
Parts per million Grains per gallon 0.05841

Parts per million Tons per acre-foot 0.00136
Parts per million Tons per day Second-feet!0.0027
Ca
C2
CaCO
3
2.497
CaCl
2
CaCO
3
0.9018
HCO
3
K1
CaCO
3
0.8202
HCO
3
K1
CO
3
K2
0.4917
Mg
C2
CaCO
3
4.116

MgCl
2
CaCO
3
1.051
Na
2
CO
3
CaCO
3
0.9442
Fe
C3
H
2
SO
4
2.634
NO
3
K1
N 0.2259
NNO
3
K1
4.4266
Parts Per Million to Equivalent Per Million
Ion Multiply By Ion Multiply By
Aluminum (Al

C3
) 0.11119 Iron (Fe
C3
) 0.05372
Barium (Ba
C2
) 0.01456 Lead (Pb
C3
) 0.00965
Bicarbonate (HCO
3
K1
) 0.01639 Lithium (Li
C1
) 0.14409
Bromide (Br
K1
) 0.01251 Magnesium (Mg
C2
) 0.08224
Calcium (Ca
C2
) 0.04990 Manganese (Mn
C2
) 0.03640
Carbonate (CO
3
K1
) 0.03333 Manganese (Mn
C4

) 0.07281
Chloride (Cl
K1
) 0.02820 Nitrate (NO
3
K1
) 0.01613
Chromium (Cr
C6
) 0.11536 Phosphate (PO
4
K3
) 0.03159
Copper (Cu
C2
) 0.03148 Potassium (K
C1
) 0.02558
Fluoride (F
K1
) 0.05263 Sodium (Na
C1
) 0.04350
Hydrogen (H
C1
) 0.99206 Strontium (Sr
C2
) 0.02282
Hydroxide (OH
K1

) 0.05880 Sulfate (SO
4
K2
) 0.02082
Iodide (I
K1
) 0.00788 Sulfide(S
K1
) 0.06237
Iron (Fe
C2
) 0.03581 Zinc (Zn
C2
) 0.03059
Expressions of Hardness
1 grain per gallon Z1 grain CaCO
3
per U.S. gallon
1 part per million Z1 part CaCO
3
per 1,000,000 parts of water
1 English, or Clark, degree Z1 grain CaCO
3
per Imperial gallon
1 French degree Z1 part CaCO
3
per 100,000 parts of water
1 German degree Z1 part CaO per 100,000 parts of water
Conversions
1 grain per U.S. gallon Z17.1 ppm, as CaCO

3
1 English degree Z14.3 ppm, as CaCO
3
1 French degree Z10 ppm, as CaCO
3
1 German degree Z17.9 ppm, as CaCO
For most waters, 1 part per millionZ1 mg/l. The U.S. Geological Survey has arbitrarily selected 7,000 ppm as the concentration above
which a density correction must be made: the determined concentration of each constituent must be divided by the density to give the
correct parts per million. The computation is made before rounding the results.
Parts per million are converted to equivalents per million by multiplying ppm by the reciprocals of combining weights of the appropriate ions
(see table). The combining weight is equal to the molecular or ionic weight divided by the ionic charge, or valence.
Specific Conductance Relations (Adapted from USGS Water Supply Paper 1454)
For most natural waters of a mixed type, the specific conductance, in micromhos (1 micromhoZ10
K6
mho. The mho is unit of conductance;
thus, a body has a conductance of one mho if one ampere of electric current flows when the potential difference is one volt. The
conductance of a body in mhos is the reciprocal of the value of its resistance in ohms.), multiplied by 0.65 approximates the residue on
evaporation in parts per million. This does not approach an exact relation, and usually increases as the total dissolved solids exceed 2000–
3000 ppm. For waters containing appreciable concentrations of free acid, caustic alkalinity, or sodium chloride, the factor may be much less
than 0.65. The relationship for any water becomes indefinite as saturation is approached.
With similar limitations, the specific conductance divided by 100 approximates the equivalents per million of cations or anions.
THE WATER ENCYCLOPEDIA: HYDROLOGIC DATA AND INTERNET RESOURCES13-6
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SECTION 13C LENGTH
Table 13B.11 Formula Weights and Equivalent Weights of Ions Found
in Water
Ion Formula Weight Equivalent Weight
AI
C3
27.00 9.00

Ba
C2
137.00 68.70
HCO
3
K1
61.00 61.00
Br
K1
79.90 79.90
Ca
C2
40.10 20.00
CO
3
K2
60.00 30.00
CI
K1
35.50 35.50
Cr
C6
52.00 8.67
Cu
C2
63.60 31.80
F
C1
19.00 19.00
H

C1
1.01 1.01
OH
K1
17.00 17.00
I
K1
127.00 127.00
Fe
C2
55.80 27.90
Fe
C3
55.80 18.60
Pb
C2
207.00 104.00
Li
C1
6.94 6.94
Mn
C2
54.90 27.50
Mn
C4
54.90 13.70
NO
3
K1
62.00 62.00

PO
4
K3
95.00 31.70
K
C1
39.10 39.10
Na
C1
23.00 23.00
Sr
C2
87.60 43.80
SO
4
K2
96.10 48.00
S
K2
32.10 16.00
Zn
C2
65.40 32.70
Note: Weights expressed to three significant figures.
Table 13C.12 Conversion Factors for Length
1 mil Z1!10
K3
in.
Z0.0254 mm
1 in. Z0.08333 ft

Z0.0278 yd
Z25.4 mm
Z2.54 cm
Z0.0254 m
1ft Z12 in.
Z0.3333 yd
Z1.89!10
K4
mi
Z30.48 cm
Z0.3048 m
Z3.048!10
K4
km
1yd Z36 in.
Z3ft
Z5.68!10
K4
mi
Z91.44 cm
Z0.9144 m
Z9.144!10
K4
km
1mi Z5280 ft
Z1760 yd
Z1609.3 m
Z1.609 km
(Continued)
CONSTANTS AND CONVERSION FACTORS 13-7

q 2006 by Taylor & Francis Group, LLC
SECTION 13D AREA
Table 13C.12 (Continued)
1 mm Z1!10
K3
mm
Z3.937!10
K5
in.
1mm Z0.03937 in.
Z0.1 cm
Z1!10
K3
m
1cm Z0.3937 in.
Z0.03281 ft
Z0.01094 yd
Z10 mm
Z1!10
K5
km
1m Z39.37 in.
Z3.281 ft
Z1.094 yd
Z6.21!10
K4
mi
Z1000 mm
Z100 cm
Z1!10

K3
km
1km Z3280.8 ft
Z1093.6 yd
Z0.621 mi
Z1!10
5
cm
Z1000 m
1 fathom Z6ft
1 league (land) Z5280 yd
Z3mi
Z4.828 km
1 International nautical mile Z6076.1 ft
Z1.151 mi
Z1.852 km
10 mm Z1cm
10 cm Z1dm
10 dm Z1m
10 m Z1 dam
10 dam Z1hm
10 hm Z1km
Table 13D.13 Conversion Factors for Area
1 sq in. Z6.944!10
K3
ft
2
Z7.716!10
4
yd

2
Z6.452 cm
2
1sqft Z144 in.
2
Z0.1111 yd
2
Z2.296!10
K5
acre
Z3.587!10
K8
mi
2
Z929.0 cm
2
1sqyd Z1296 in.
2
Z9ft
2
Z2.066!10
4
acres
Z3.228!10
K7
mi
2
Z0.8361 m
2
Z8.361!10

K5
hectare
1 Acre Z43,560 ft
2
Z4840 yd
2
Z1.562!10
K3
mi
2
Z4046.9 m
2
Z0.4047 hectare
Z4.047!10
K3
km
2
(Continued)
THE WATER ENCYCLOPEDIA: HYDROLOGIC DATA AND INTERNET RESOURCES13-8
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SECTION 13E VOLUME
Table 13D.13 (Continued)
1sqmi Z2.788!10
7
ft
2
Z3.098!10
6
yd
2

Z640 acres
Z2.590!10
6
m
2
Z259.0 hectares
Z2.590 km
2
Z1 section (of land)
1 Township Z36 mi
2
Z36 sections (of land)
1sqcm Z0.1550 in.
2
Z1.076!10
K3
ft
2
Z1.196!10
K4
yd
2
Z1!10
K4
yd
2
1sqm Z1550.0 in.
2
Z10.76 ft
2

Z1.196 yd
2
Z2.471!10
K4
acre
Z1!10
K4
hectare
Z1!10
8
km
2
1 Hectare Z1.076!10
5
ft
2
Z1.196!10
4
yd
2
Z2.471 acres
Z3.861!10
K3
mi
2
Z1!10
4
m
2
Z0.01 km

2
1sqkm Z1.076!10
7
ft
2
Z1.196!10
6
yd
2
Z247.1 acres
Z0.3861 mi
2
Z1!10
6
mi
2
Z100 hectares
Table 13E.14 Conversion Factors for Volume
1 cu in. Z4.329!10
K3
gal
Z5.787!10
4
ft
3
Z16.39 cm
3
Z0.01639 l
1 gal Z231 in.
3

Z0.1337 ft
3
Z4.951!10
K3
yd
3
Z3.785!10
K3
cm
3
Z3.785 l
Z3.785!10
K3
m
3
1cuft Z1728 in.
3
Z7.481 gal
Z0.03704 yd
3
Z2.832!10
4
cm
3
Z28.32 l
Z0.02832 m
3
1cuyd Z4.666!10
4
in.

3
Z27 ft
3
Z0.7646 m
3
Z6.198!10
K4
acre-ft
1 Acre-in. Z2.715!10
4
gal
Z3630 ft
3
1 Acre-ft Z3.259!10
5
gal
Z43,560 ft
3
Z1234 m
3
(Continued)
CONSTANTS AND CONVERSION FACTORS 13-9
q 2006 by Taylor & Francis Group, LLC
Table 13E.14 (Continued)
1cucm Z0.06102 in.
3
Z2.642!10
4
gal
Z3.532!10

K5
ft
3
Z1!10
K3
l
1l Z61.02 in.
3
Z0.2642 gal
Z0.03532 ft
3
Z1000 cm
3
Z1!10
K3
m
3
1cum Z264.2 gal
Z35.32 ft
3
Z1.307 yd
3
Z1!10
6
cm
3
Z1000 l
1 Imperial gallon Z277.4 in.
3
Z1.201 gal

Z0.1604 ft
3
Z4.546 l
1 cfs-day Z1.98 acre-ft
Z0.0372 in. mi
2
1 in. of rain Z5.610 gal/yd
2
Z2.715!10
4
gal/acre
1 in mi
2
.
Z2.323!10
6
ft
3
Z53.3 acre-ft
Z26.9 cfs-days
1 Barrel (oil) Z42 gal
1 Million gallons Z3.069 acre-ft
1 Pint Z28.875 in.
3
Z0.5 qt
Z0.473 l
1 Quart Z57.75 in.
3
Z2pt
Z0.25 gal

Z0.946 l
Table 13E.15 Areas and Volumes of Vertical Cylindrical Tanks and Wells
Diameter
Area, sq ft
or cu ft per
ft of Depth
U.S. gal per
ft of Depth Diameter
Area, sq ft
or cu ft per
ft of Depth
U.S. gal per
ft of Depth Diameter
Area, sq ft
or cu ft per
ft of Depth
U.S. gal per
ft of Depth
1
0
0.785 5.87 6
0
28.27 211.5 28
0
615.8 4,606
1
0
1
00
0.922 6.89 6

0
3
00
30.68 229.5 28
0
6
00
637.9 4,772
1
0
2
00
1.069 8.00 6
0
6
00
33.18 248.2 29
0
660.5 4,941
1
0
3
00
1.227 9.18 6
0
9
00
35.78 267.7 29
0
6

00
683.5 5,113
1
0
4
00
1.396 10.44 7
0
38.48 287.9 30
0
706.9 5,288
1
0
5
00
1.576 11.79 7
0
3
00
41.28 308.8 31
0
754.8 5,646
1
0
6
00
1.767 13.22 7
0
6
00

44.18 330.5 32
0
804.3 6,016
1
0
7
00
1.969 14.73 7
0
9
00
47.17 352.9 33
0
855.3 6,398
1
0
8
00
2.182 16.32 8
0
50.27 376.0 34
0
907.9 6,792
1
0
9
00
2.405 17.99 8
0
3

00
53.46 399.9 35
0
962.1 7,197
1
0
10
00
2.640 19.75 8
0
6
00
56.75 424.5 36
0
1,018 7,616
1
0
11
00
2.885 21.58 8
0
9
00
60.13 449.8 37
0
1,075 8,043
2
0
3.142 23.50 9
0

63.62 475.9 38
0
1,134 8,483
2
0
1
00
3.409 25.50 9
0
3
00
67.20 502.7 39
0
1,195 8,940
2
0
2
00
3.637 27.58 9
0
6
00
70.88 530.2 40
0
1,257 9,404
2
0
3
00
3.976 29.74 9

0
9
00
74.66 558.5 41
0
1,320 9,876
2
0
4
00
4.276 31.99 10
0
78.54 587.5 42
0
1,385 10,360
2
0
5
00
4.587 34.31 10
0
6
00
86.59 647.7 43
0
1,452 10,860
2
0
6
00

4.909 36.72 11
0
95.03 710.9 44
0
1,521 11,370
2
0
7
00
5.241 39.21 11
0
6
00
103.9 777.0 45
0
1,590 11,900
(Continued)
THE WATER ENCYCLOPEDIA: HYDROLOGIC DATA AND INTERNET RESOURCES13-10
q 2006 by Taylor & Francis Group, LLC
Table 13E.15 (Continued)
Diameter
Area, sq ft
or cu ft per
ft of Depth
U.S. gal per
ft of Depth Diameter
Area, sq ft
or cu ft per
ft of Depth
U.S. gal per

ft of Depth Diameter
Area, sq ft
or cu ft per
ft of Depth
U.S. gal per
ft of Depth
2
0
8
00
5.585 41.78 12
0
113.1 846.0 46
0
1,662 12,430
2
0
9
00
5.940 44.43 12
0
6
00
122.7 918.0 47
0
1,735 12,980
2
0
10
00

6.305 47.16 13
0
132.7 992.9 48
0
1,810 13,540
2
0
11
00
6.681 49.98 13
0
6
00
143.1 1,071 49
0
1,886 14,110
3
0
7.069 52.88 14
0
153.9 1,152 50
0
1,964 14,690
3
0
1
00
7.467 55.86 14
0
6

00
165.1 1,235 52
0
2,124 15,890
3
0
2
00
7.876 58.92 15
0
176.7 1,322 54
0
2,290 17,130
3
0
3
00
8.296 62.06 15
0
6
00
188.7 1,412 56
0
2,463 18,420
3
0
4
00
8.727 65.28 16
0

201.1 1,504 58
0
2,642 19,760
3
0
5
00
9.168 68.58 16
0
6
00
213.8 1,600 60
0
2,827 21,150
3
0
6
00
9.621 71.97 17
0
227.0 1,698 62
0
3,019 22,580
3
0
7
00
10.08 75.44 17
0
6

00
240.5 1,799 64
0
3,217 24,060
3
0
8
00
10.56 78.99 18
0
254.5 1,904 66
0
3,421 25,590
3
0
9
00
11.04 82.62 18
0
6
00
268.8 2,011 68
0
3,632 27,170
3
0
10
00
11.54 86.33 19
0

283.5 2,121 70
0
3,848 28,790
3
0
11
00
12.05 90.13 19
0
6
00
298.6 2,234 72
0
4,072 30,450
4
0
12.57 94.00 20
0
314.2 2,350 74
0
4,301 32,170
4
0
1
00
13.10 97.96 20
0
6
00
330.1 2,469 76

0
4,536 33,930
4
0
2
00
13.64 102.0 21
0
346.4 2,591 78
0
4,778 35,740
4
0
3
00
14.19 106.1 21
0
6
00
363.1 2,716 80
0
5,027 37,600
4
0
4
00
14.75 110.3 22
0
380.1 2,844 82
0

5,281 39,500
4
0
5
00
15.32 114.6 22
0
6
00
397.6 2,974 84
0
5,542 41,450
4
0
6
00
15.90 119.0 23
0
415.5 3,108 86
0
5,809 43,450
4
0
7
00
16.50 123.4 23
0
6
00
433.7 3,245 88

0
6,082 45,490
4
0
8
00
17.10 128.0 24
0
452.4 3,384 90
0
6,362 47,590
4
0
9
00
17.72 132.6 24
0
6
00
471.4 3,527 92
0
6,648 49,720
4
0
10
00
18.35 137.3 25
0
490.9 3,672 94
0

6,940 51,920
4
0
11
00
18.99 142.0 25
0
6
00
510.7 3,820 96
0
7,238 54,140
5
0
19.63 146.9 26
0
530.9 3,972 98
0
7,543 56,420
5
0
3
00
21.65 161.9 26
0
6
00
551.5 4,126 100
0
7,854 58,750

5
0
6
00
23.76 177.7 27
0
572.6 4,283
5
0
9
00
25.97 194.3 27
0
6
00
594.0 4,443
Table 13 E.16 Volumes of Horizontal Cylindrical Tanks
Percent Full
Diameter
(ft) 10 20 30 40 50 60 70 80 90 100
1 0.3 0.8 1.4 2.1 2.9 3.6 4.3 4.9 5.5 5.87
2 1.2 3.3 5.9 8.8 11.7 14.7 17.5 20.6 22.2 23.50
3 2.7 7.5 13.6 19.8 26.4 33.0 39.4 45.2 50.1 52.88
4 4.9 13.4 23.8 35.0 47.0 59.0 70.2 80.5 89.0 94.00
5 7.6 20.0 37.0 55.0 73.0 92.0 110.0 126.0 139.0 146.9
6 11.0 30.0 53.0 78.0 106.0 133.0 158.0 182.0 201.0 211.5
7 15.0 41.0 73.0 107.0 144.0 181.0 215.0 247.0 272.0 287.9
8 19.0 52.0 96.0 140.0 188.0 235.0 281.0 322.0 356.0 376.0
9 25.0 67.0 112.0 178.0 238.0 298.0 352.0 408.0 450.0 475.9
10 30.0 83.0 149.0 219.0 294.0 368.0 440.0 504.0 556.0 587.5

11 37.0 101.0 179.0 265.0 356.0 445.0 531.0 610.0 672.0 710.9
12 44.0 120.0 214.0 315.0 423.0 530.0 632.0 714.0 800.0 846.0
13 51.0 141.0 250.0 370.0 496.0 621.0 740.0 850.0 940.0 992.9
14 60.0 164.0 291.0 430.0 576.0 722.0 862.0 989.0 1084.0 1152.0
15 68.0 188.0 334.0 494.0 661.0 829.0 988.0 1134.0 1253.0 1322.0
Note: U.S. gallons per foot of length.
CONSTANTS AND CONVERSION FACTORS 13-11
q 2006 by Taylor & Francis Group, LLC
SECTION 13F VELOCITY
SECTION 13G FLOW RATE
Table 13F.17 Conversion Factors for Velocity
1 ft/sec Z0.682 mi/h
Z0.3048 m/sec
1 mi/h Z1.467 ft/sec
Z0.869 International knots
Z1.609 km/h
1 International knot Z1.151 mi/h
Z1.852 km/h
1 m/sec Z3.6 km/h
Z3.28 ft/sec
Z2.237 mi/h
Z1.94 knots
1 km/h Z0.621 mi/h
Z0.540 International knot
Table 13G.18 Conversion Factors for Flow Rate
1 gal/min Z1.44!10
K3
mgd
Z2.23!10
K3

cfs
Z4.42!10
K3
AF/day
Z0.0631 l/sec
Z6.31!10
K5
m
3
/sec
Z5.42 m
3
/day
1 Million gallons per day Z694 gpm
Z1.55 cfs
Z3.07 AF/day
Z43.7 l/sec
Z0.0437 m
3
/sec
Z3770 m
3
/day
1 Cubic foot per second Z449 gpm
Z0.646 mgd
Z1.98 AF/day
Z28.3 l/sec
Z0.0283 m
3
/sec

Z2450 m
3
/day
1 acre-foot per day Z226 gpm
Z0.326 mgd
Z0.505 cfs
Z14.2 l/sec
Z0.0142 m
3
/sec
Z1230 m
3
/day
1 l/sec Z15.9 gpm
Z0.0228 mgd
Z0.0353 cfs.
Z0.0703 AF/day
Z0.001 m
3
/sec
Z86.4 m
3
/day
1 Cubic meter per day second Z1.58!10
4
gpm
Z22.8 mgd
Z35.3 cfs
Z70.0 AF/day
Z1000 l/sec

Z8.64!10
4
m
3
/day
1 Cubic per day Z0.183 gpm
Z2.64!10
K4
mgd
Z4.09 x
:
10
K4
cfs
(Continued)
THE WATER ENCYCLOPEDIA: HYDROLOGIC DATA AND INTERNET RESOURCES13-12
q 2006 by Taylor & Francis Group, LLC
Table 13G.19 Conversion of Daily Consumptive Use Rates to Equivalent Continuous Flow Rates per Unit Area
Equivalent Continuous Flow Rates
Consumptive Use of Water by Crop per Hectare per Acre
Millimetres
per Day
Inches
per Day
Litres
per Second
Cubic Metres
per Day
Cubic Feet
per Second

U.S. Gallons
per Minute
a
2 0.08 0.23 20 0.0033 1.5
3 0.12 0.35 30 0.0050 2.2
4 0.16 0.46 40 0.0067 3.0
5 0.20 0.58 50 0.0083 3.7
6 0.24 0.69 60 0.0100 4.5
7 0.28 0.81 70 0.0117 5.2
8 0.32 0.92 80 0.0133 6.0
9 0.36 1.04 90 0.0150 6.7
10 0.40 1.15 100 0.0167 7.5
a
To convert to imperial gallons per minute, multiply values by 0.833.
Source: From Food and Agriculture Organization of the United Nations, 1974, Surface Irrigation. Copyright FAO. Reprinted with
permission.
Table 13G.18 (Continued)
Z8.11!10
K4
AF/day
Z0.0116 l/sec
Z1.16!10
K5
m
3
/sec
1 Miner’s inch Z0.025 cubic foot per second
(in Arizona, California,
Montana, and Oregon)
Z0.02 cubic foot per second

(in Idaho, Kansas, Nebraska,
New Mexico, North and
South Dakota, and Utah)
Z0.026 cubic foot per second
(in Colorado)
Z0.028 cubic foot per second
(in British Columbia)
Table 13G.20 Time Required to Supply One Acre with
1 in. of Water
Flow Rate Time
gpm cfs Hr Min
100 0.22 4 32
150 0.33 3 01
200 0.45 2 16
250 0.56 1 48
300 0.67 1 30
350 0.78 1 18
400 0.89 1 08
450 1.00 1 00
500 1.11 0 54
600 1.34 0 46
700 1.56 0 39
800 1.78 0 34
900 2.01 0 30
1000 2.23 0 27
1100 2.45 0 24
1200 2.67 0 22
1300 2.90 0 21
1400 3.12 0 20
1500 3.34 0 18

CONSTANTS AND CONVERSION FACTORS 13-13
q 2006 by Taylor & Francis Group, LLC
SECTION 13H WEIGHT
SECTION 13I PRESSURE
Table 13H.21 Conversion Factors for Weight
1 Grain Z2.286!10
K3
oz
Z1.429!10
K4
lb
1 Ounce Z437.5 gr
Z0.0625 lb
Z28.35 gm
1 Pound Z7000 gr
Z16 oz
Z453.6 gm
Z0.4536 kg
1 Short ton Z2000 lb
Z907.2 kg
Z0.9072 m ton
1 Long ton Z2240 lb
Z1016.0 kg
Z1.016 m ton
1 Metric ton Z2204.6 lb
Z1000 kg
Z1.102 short ton
Z0.9842 long ton
1g Z15.43 gr
Z0.03527 oz

Z2.205!10
K3
lb
Z0.001 kg
1 kilogram Z35.27 oz
Z2.205 lb
Z1000 gm
Z0.001 m ton
Table 13I.22 Conversion Factors for Pressure
1 in. of water at 628F Z0.0361 lb/in.
2
Z5.196 lb/ft
2
Z0.0735 in. of mercury at 628F
1 ft of water at 628F Z0.433 lb/in.
2
Z62.36 lb/ft
2
Z0.833 in. of mercury at 628F
Z2.950!10
K2
atmosphere
1 Atmosphere Z14.7 lb/in.
2
Z2116 lb/ft
2
Z33.95 feet of water at 628F
Z29.92 in. of mercury at 328F
Z1013.2 millibars
Z760 mm of mercury at 328F

Z1033 gm/cm
2
Z1.033 kg/cm
2
1 Pound per sq in. Z2.309 feet of water at 628F
Z2.036 in. of mercury at 328F
Z0.06804 atmosphere
Z0.07031 kg/cm
2
1 in. of mercury at 328F Z0.4192 lb/in.
2
Z1.133 feet of water at 328F
1 kg/sq cm Z14.22 lb/in.
2
1 Bar Z1!10
6
dynes/cm
2
Z1019.8 gm/cm
2
Z0.9869 atmosphere
Z14.50 lb/in.
2
Z1000 millibars
THE WATER ENCYCLOPEDIA: HYDROLOGIC DATA AND INTERNET RESOURCES13-14
q 2006 by Taylor & Francis Group, LLC
SECTION 13J PERMEABILITY
Table 13J.23 Units and Conversion Factors for Permeability
Permeability Units
a

Laboratory (standard) coefficient of permeability 1K
s
Z
1 gal: of water at 608F=day
ð1ft
2
Þð1ft=ftÞ
Field coefficient of permeability 1K
f
Z
1 gal: of water at field temperature=day
ð1ft!1miÞð 1ft=miÞ
Specific (intrinsic) permeability 1 darcyZ
1 centipoise!1cm
3
=secÞ=1cm
2
1 atmosphere=1cm
Conversion Factors
Permeability
1K
s
Z4.72!10
K5
cm/sec
Z0.0408 m/day
Z0.134 ft /day
Z1.43!10
K6
ft/sec

1 Darcy Z0.987!10
K8
cm
2
Z1.062!10
K11
ft
2
Z18.2 K
s
for water at 608F
Z0.966!10
K3
cm/sec for water at 208C
1 Millidarcy Z1.82!10
K2
K
s
for water at 608F
1 cm/sec Z1.02!10
K5
cm
2
for water at 208C
1 m/sec Z2.12!10
6
gpd/ft
2
1 m/day Z24.5 gpd/ft
2

Transmissivity
1m
2
/sec Z6.96!10
6
gpd/ft
1m
2
/day Z80.5 gpd/ft
a
In groundwater investigations, the water-transmitting capability of an aquifer is commonly expressed in terms
of a Coefficient of Transmissivity, which is the product of the Coefficient of Permeability of the aquifer material
and the thickness of the aquifer.
CONSTANTS AND CONVERSION FACTORS 13-15
q 2006 by Taylor & Francis Group, LLC
SECTION 13K POWER
Table 13K.24 Conversion Factors for Power
1hp Z.746 kW or 746 W
Z33,000 ft lb/min
Z550 ft lb/sec
Z8760 hp-h/yr
Z6535 kWh/yr
H.P. Input ZHorsepower input to motor
Z1.34!kilowatts input to motor
Water H.P. ZH.P. required to lift water at a definite rate to a given
distance assuming 100% efficiency
Z
G:P:M:!total head ðin: ftÞ
3960
Brake H.P. ZH.P. delivered by motor

ZH.P. required by pump
ZH.P. input motor!efficiency
Z1.34!KW input!motor efficiency
Z
Water H:P:
pump efficiency
Z
G:P:M:!total headðftÞ
3960!pump efficiency
Z
G:P:H:!total headðlb=sq in:Þ
103; 000!pump efficiency
1 kilowatt Z1.3405 Horsepower
Z8760 kWh/yr
Efficiency Z
Power output
Power input
Motor Efficiency Z
H:P: output
KW input!1:34
Pump Efficiency Z
G:P:M:!total headðftÞ
3960!B:H:P
Plant Efficiency Z
G:P:M:!total headðftÞ
5300!KW input
Table 13K.25 Horsepower Required to Pump Water
Gallons per Cubic Feet per
Horsepower Required for Elevations of
Minute Second 10 ft 20 ft 30 ft 40 ft 50 ft 60 ft 70 ft 80 ft

100 0.22 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0
150 0.33 0.8 1.5 2.3 3.0 3.8 4.6 5.3 6.1
200 0.45 1.0 2.0 3.0 4.0 5.0 6.1 7.1 8.1
250 0.56 1.3 2.5 3.8 5.0 6.3 7.6 8.8 10.1
300 0.67 1.5 3.0 4.6 6.1 7.6 9.1 10.6 12.1
350 0.78 1.8 3.5 5.3 7.1 8.8 10.6 12.4 14.1
400 0.89 2.0 4.0 6.1 8.1 10.1 12.1 14.1 16.2
450 1.00 2.3 4.6 6.8 9.1 11.4 13.6 15.9 18.2
500 1.11 2.5 5.0 6.7 10.1 12.6 15.2 17.7 20.2
600 1.34 3.0 6.1 9.1 12.1 15.2 18.2 21.2 24.2
700 1.56 3.5 7.1 10.6 14.1 17.7 21.2 24.8 28.3
800 1.78 4.0 8.1 12.1 16.2 20.2 24.2 28.3 32.3
900 2.01 4.6 9.1 13.6 18.2 22.7 27.3 31.8 36.4
1000 2.23 5.0 10.1 15.2 20.2 25.2 30.3 35.4 40.4
1250 2.78 6.3 12.6 18.9 25.2 31.6 37.9 44.2 50.5
1500 3.34 7.6 15.2 22.7 30.3 37.9 45.4 53.0 60.6
Note: Efficiency of pumping plant 50 percent of theoretical. Use for estimating only.
THE WATER ENCYCLOPEDIA: HYDROLOGIC DATA AND INTERNET RESOURCES13-16
q 2006 by Taylor & Francis Group, LLC
SECTION 13L TEMPERATURE
Table 13K.26 Theoretical Power of American Multiblade Windmills of Different Diameters for Several Wind Velocities
Wind Velocity
Horsepower
a
from Wheel Diameter (in feet) of
(mi/h) 6 8 10 12 14 16 18
6 0.05 0.06 0.08 0.09
8 0.05 0.07 0.10 0.14 0.18 0.23
10 0.05 0.09 0.14 0.21 0.28 0.36 0.46
12 0.09 0.15 0.24 0.36 0.49 0.63 0.81

15 0.18 0.31 0.48 0.68 0.94 1.21 1.55
20 0.40 0.72 1.12 1.62 2.20 2.88 3.65
25 0.79 1.41 2.21 3.20 4.34 5.67 7.20
a
HorsepowerZCD
2
V
3
. Where C, the power coefficient for American multiblade type wheelZ0.45!10
K6
, when the tip speed is
approximately the same as the velocity of the wind; DZdiameter of the wheel in feet; and VZindicated velocity of the wind in feet per
second (Robinson anemometer).
Source: From U.S. Dept. of Agriculture.
Table 13L.27 Conversion Factors for Temperature, Temperature Conversion Fahrenheit 4 Centigrade
8
Fto
8
C (Range 0–279
8
F)
8
F
8
C
8
F
8
C
8

F
8
C
8
F
8
C
8
F
8
C
0 K17.78 56 13.33 112 44.44 168 75.56 224 106.67
1 K17.22 57 13.89 113 45.00 169 76.11 225 107.22
2 K16.67 58 14.44 114 45.56 170 76.67 226 107.78
3 K16.11 59 15.00 115 46.11 171 77.22 227 108.33
4 K15.56 60 15.56 116 46.67 172 77.78 228 108.89
5 K15.00 61 16.11 117 47.22 173 78.33 229 109.44
6 K14.44 62 16.67 118 47.78 174 78.89 230 110.00
7 K13.89 63 17.22 119 48.33 175 79.44 231 110.56
8 K13.33 64 17.78 120 48.89 176 80.00 232 111.11
9 K12.78 65 18.33 121 49.44 177 80.56 233 111.67
10 K12.22 66 18.89 122 50.00 178 81.11 234 112.22
11 K11.67 67 19.44 123 50.56 179 81.67 235 112.78
12 K11.11 68 20.00 124 51.11 180 82.22 236 113.33
13 K10.56 69 20.56 125 51.67 181 82.78 237 113.89
14 K10.00 70 21.11 126 52.22 182 83.33 238 114.44
15 K9.44 71 21.67 127 52.78 183 83.89 239 115.00
16 K8.89 72 22.22 128 53.33 184 84.44 240 115.56
17 K8.33 73 22.78 129 53.89 185 85.00 241 116.11
18 K7.78 74 23.33 130 54.44 186 85.56 242 116.67

19 K7.22 75 23.89 131 55.00 187 86.11 243 117.22
20 K6.67 76 24.44 132 55.56 188 86.67 244 117.78
21 K6.11 77 25.00 133 56.11 189 87.22 245 118.33
22 K5.56 78 25.56 134 56.67 190 87.78 246 118.89
23 K5.00 79 26.11 135 57.22 191 88.33 247 119.44
24 K4.44 80 26.67 136 57.78 192 88.89 248 120.00
25 K3.89 81 27.22 137 58.33 193 89.44 249 120.56
26 K3.33 82 27.78 138 58.89 194 90.00 250 121.11
27 K2.78 83 28.33 139 59.44 195 90.56 251 121.67
28 K2.22 84 28.89 140 60.00 196 91.11 252 122.22
29 K1.67 85 29.44 141 60.56 197 91.67 253 122.78
30 K1.11 86 30.00 142 61.11 198 92.22 254 123.33
31 K0.56 87 30.56 143 61.67 199 92.78 255 123.89
32 0.00 88 31.11 144 62.22 200 93.33 256 124.44
33 0.56 89 31.67 145 62.78 201 93.89 257 125.00
(Continued)
CONSTANTS AND CONVERSION FACTORS 13-17
q 2006 by Taylor & Francis Group, LLC
Table 13L.27 (Continued)
8
Fto
8
C (Range 0–279
8
F)
8
F
8
C
8

F
8
C
8
F
8
C
8
F
8
C
8
F
8
C
34 1.11 90 32.22 146 63.33 202 94.44 258 125.56
35 1.67 91 32.78 147 63.89 203 95.00 259 126.11
36 2.22 92 33.33 148 64.44 204 95.56 260 126.67
37 2.78 93 33.89 149 65.00 205 96.11 261 127.22
38 3.33 94 34.44 150 65.56 206 96.67 262 127.78
39 3.89 95 35.00 151 66.11 207 97.22 263 128.33
40 4.44 96 35.56 152 66.67 208 97.78 264 128.89
41 5.00 97 36.11 153 67.22 209 98.33 265 129.44
42 5.56 98 36.67 154 67.78 210 98.89 266 130.00
43 6.11 99 37.22 155 68.33 211 99.44 267 130.56
44 6.67 100 37.78 156 68.89 212 100.00 268 131.11
45 7.22 101 38.33 157 69.44 213 100.56 269 131.67
46 7.78 102 38.89 158 70.00 214 101.11 270 132.22
47 8.33 103 39.44 159 70.56 215 101.67 271 132.78
48 8.89 104 40.00 160 71.11 216 102.22 272 133.33

49 9.44 105 40.56 161 71.67 217 102.78 273 133.89
50 10.00 106 41.11 162 72.22 218 103.33 274 134.44
51 10.56 107 41.67 163 72.78 219 103.89 275 135.00
52 11.11 108 42.22 164 73.33 220 104.44 276 135.56
53 11.67 109 42.78 165 73.89 221 105.00 277 136.11
54 12.22 110 43.33 166 74.44 222 105.56 278 136.67
55 12.78 111 43.89 167 75.00 223 106.11 279 137.22
8
Fto
8
C (Range 280–300
8
F)
8
Cto
8
F (Range 0–150
8
C)
8
F
8
C
8
C
8
F
8
C
8

F
8
C
8
F
280 137.78 0 32.0 56 132.8 112 233.6
281 138.33 1 33.8 57 134.6 113 235.4
282 138.89 2 35.6 58 136.4 114 237.2
283 139.44 3 37.4 59 138.2 115 239.0
284 140.00 4 39.2 60 140.0 116 240.8
285 140.56 5 41.0 61 141.8 117 242.6
286 141.11 6 42.8 62 143.6 118 244.4
287 141.67 7 44.6 63 145.4 119 246.2
288 142.22 8 46.4 64 147.2 120 248.0
289 142.78 9 48.2 65 149.0 121 249.8
290 143.33 10 50.0 66 150.8 122 251.6
291 143.89 11 51.8 67 152.6 123 253.4
292 144.44 12 53.6 68 154.4 124 255.2
293 145.00 13 55.4 69 156.2 125 257.0
294 145.56 14 57.2 70 158.0 126 258.8
295 146.11 15 59.0 71 159.8 127 260.6
296 146.67 16 60.8 72 161.6 128 262.4
297 147.22 17 62.6 73 163.4 129 264.2
298 147.78 18 64.4 74 165.2 130 266.0
299 148.33 19 66.2 75 167.0 131 267.8
300 148.89 20 68.0 76 168.8 132 269.6
21 69.8 77 170.6 133 271.4
22 71.6 78 172.4 134 273.2
23 73.4 79 174.2 135 275.0
24 75.2 80 176.0 136 276.8

25 77.0 81 177.8 137 278.6
26 78.8 82 179.6 138 280.4
27 80.6 83 181.4 139 282.2
28 82.4 84 183.2 140 284.0
29 84.2 85 185.0 141 285.8
30 86.0 86 186.8 142 287.6
31 87.8 87 188.6 143 289.4
32 89.6 88 190.4 144 291.2
(Continued)
THE WATER ENCYCLOPEDIA: HYDROLOGIC DATA AND INTERNET RESOURCES13-18
q 2006 by Taylor & Francis Group, LLC
Table 13L.27 (Continued)
8
Fto
8
C (Range 280–300
8
F)
8
Cto
8
F (Range 0–150
8
C)
8
F
8
C
8
C

8
F
8
C
8
F
8
C
8
F
33 91.4 89 192.2 145 293.0
34 93.2 90 194.0 146 294.8
35 95.0 91 195.8 147 296.6
36 96.8 92 197.6 148 298.4
37 98.6 93 199.4 149 300.2
38 100.4 94 201.2 150 302.0
39 102.2 95 203.0
40 104.0 96 204.8
41 105.8 97 206.6
42 107.6 98 208.4
43 109.4 99 210.2
44 112.2 100 212.0
45 113.0 101 213.8
46 114.8 102 215.6
47 116.6 103 217.4
48 118.4 104 219.2
49 120.2 105 221.0
50 122.0 106 222.8
51 123.8 107 224.6
52 125.6 108 226.4

53 127.4 109 228.2
54 129.2 110 230.0
55 131.0 111 231.8
Note: Temperature Conversions:
8
FZ9/5 (
8
C)C32;
8
CZ5/9 (
8
FK32).
Table 13L.27 (Continued)
CONSTANTS AND CONVERSION FACTORS 13-19
q 2006 by Taylor & Francis Group, LLC