 | Sourcebook of Alternative Technologies for Freshwater Augmentation in Latin America and the Caribbean (UNEP-IETC - OAS, 1998, 247 p.) |
 |  | Part D. Annexes |
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Annex 4 - Table of conversion factors for metric and english units
This water-quantity equivalents and conversion factor list is for those interested in converting units. The right-hand column includes units expressed in two systems - U.S. Customary and International System (metric). Units, which are written in abbreviated form below, are spelled out in parentheses the first time they appear. To convert from the unit in the left-hand column to that in the right, multiply by the number in the right-hand column. Most of the quantities listed were rounded to five significant figures. However, for many purposes, the first two or three significant figures are adequate for determining many water-quantity relations, such as general comparisons of water availability with water use or calculations in which the accuracy of the original data itself does not justify more than three significant figures. Quantities shown in italics are exact equivalents - no rounding was necessary. Regarding length of time, each calendar year is assumed (for this list) to consist of 365 days.
|
U.S. Customary |
U.S. Customary or Metric | |
|
Length | ||
|
1 in (inch) |
= |
25.4 mm (millimeters) |
|
1 ft(foot) |
= |
0.3048 m (meter) |
|
1 mi (mile, statute) |
= |
5 280 ft |
|
= |
1 609.344 m | |
|
= |
1.609344 km (kilometers) | |
|
Area | ||
|
1 ft2 (square foot) |
= |
0.09290304 m2 (square
meter) |
|
1 acre |
= |
43 560 ft2 |
|
= |
0.0015 62 5 mi2 | |
|
= |
0.40469 ha (hectare) | |
|
1mi2 |
= |
640 acres |
|
= |
259 ha | |
|
= |
2.59 km2 (square
kilometers) | |
|
Volume or Capacity (liquid measure) | ||
|
1 qt (quart, U.S.) |
= |
0.94635 l (liter) |
|
1 gal (gallon, U.S.) |
= |
231 in3 (cubic
inches) |
|
= |
0.13368 ft3 (cubic
foot) | |
|
= |
3.78541 | |
|
= |
0.003 7854 m3 (cubic
meter) | |
|
1 Mgal (million gallon) |
0.1 3368 Mft3 (million cubic
feet) | |
|
1 Mgal |
= |
3.0689 acre-ft (acre-feet) |
|
= |
3,785.4 m3 | |
|
1ft3 |
= |
1,728. In3 |
|
= |
7.4805 gal | |
|
= |
28.317 l | |
|
= |
0.028317m3 | |
|
1 Mft3 |
= |
28,317m3 |
|
1 acre-ft (volume of water, 1 ft deep, covering an area of 1
acre) |
= |
43.560 ft3 |
|
= |
0.32585 Mgal | |
|
= |
1,233.5 m3 | |
|
1 mi3 (cubic mile) |
= |
1,101.1 billion gal |
|
= |
147.20 billion ft3 | |
|
= |
3.3792 million acre-ft | |
|
= |
4.1682 km3 (cubic
kilometers) | |
|
Speed (or, when used In a vector sense,
velocity) | ||
|
1 ft/s (foot per second) |
= |
0.3048 m/s (meter per second) |
|
= |
0.68182 mi/hour (mile per hour) | |
|
1 mi/hr |
= |
1.4667 ft/s |
|
= |
0.44704 m/s | |
|
Volume per Unit of Time (discharge, water supply, water use,
and so forth) | ||
|
1 gpm (gallon per minute) |
= |
0.00144 mgd (million gallons per day) |
|
= |
0.0022280 ft3/s (cubic foot per
second) | |
|
= |
0.0044192 acre-ft/d (acre-foot per day) | |
|
= |
3.7854 l/min (liters per minute) | |
|
= |
0.063090 l/s (liters per second) | |
|
1 mgd |
= |
694.44 gal/min |
|
= |
1.5472 ft3/s | |
|
= |
3.0689 acre-ft/d | |
|
= |
1,120.0 acre-ft/d (acre-feet per year) | |
|
= |
0.043813 m3/s (cubic meter per
second) | |
|
= |
3,785.4 m3/d (cubic meters per
day) | |
|
1 billion gal/yr (billion gallons per year) |
= |
0.0013817 km3/yr (cubic kilometer per
year) |
|
1 ft3/s |
= |
2.7397 mgd |
|
= |
448.83 gal/min | |
|
= |
0.6463 2 mgd | |
|
= |
1.9835 acre-ft/d | |
|
= |
723.97 acre-ft/yr | |
|
= |
28.317 l/s | |
|
= |
0.028317 m3/d | |
|
= |
2,446.6 m3/d | |
|
= |
0.00089300 km3/yr | |
|
1 acre-ft/yr |
= |
892.74 gal/d (gallons per day) |
|
= |
0.61996 gal/min | |
|
= |
0.0013813 ft3/s | |
|
= |
3.3794 m3/d | |
|
1 acre-ft/d |
= |
0.50417 ft3/s |
|
Volume, Discharge, or Use per Unit of Area | ||
|
1 in of rain or runoff |
= |
17.379 Mgal/mi3 |
|
= |
27,154. Gal/acre (gallons per acre) | |
|
= |
25,400.
M3/km2 (cubic meters per
square kilometer) | |
|
1 in/yr |
= |
0.047613 (Mgal/d)/mi2 |
|
= |
0.073668 (ft/s)/mi2 | |
|
1 (Mgal/d)/mi2 |
= |
21.003 in/yr (inches of rain or runqffper
year) |
|
1 (ft3/s)mi2 |
= |
13.574 in/yr |
|
= |
0.010933
(m3/s)/km2 (cubic meter per
second per square kilometer) | |
|
Mass (pure water in dry air) | ||
|
1 gal at 15° Celsius (59° Fahrenheit) |
= |
8.3290 lb (pounds avoir du pois) |
|
1 gal at 4° Celsius (39.2° Fahrenheit) |
= |
8.3359 lb |
|
1 lb |
= |
0.45359 kg (kilogram) |
|
1 ton, short (2,000 lb) |
= |
0.90718 Mg (megagram) or ton, metric |
Prepared by
John C. Krammer, U.S. Geological
Survey (National Water Summary
1990-1991).
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