Cover Image
close this bookSourcebook of Alternative Technologies for Freshwater Augmentation in some Asian Countries (UNEP-IETC, 1998)
View the document(introduction...)
View the documentForeword
close this folderPart A - Introduction
View the document1. The freshwater imperative
View the document2. Objectives
View the document3. Organisation of the source book
View the document4. Survey methodology
View the document5. Results of the survey
View the document6. Recommendations of the workshop
View the document7. Information sources
close this folderPart B - Technology profiles
close this folder1. Water conservation technologies
View the document(introduction...)
View the document1.1 Dual water distribution system
View the document1.2 Evaporation reduction
View the document1.3 Coconut pick-ups
close this folder2. Wastewater treatment and reuse technologies
View the document2.1 Sewage reclamation using conventional wastewater treatment
View the document2.2 Sewage reclamation using reverse osmosis
View the document2.3 Wastewater treatment using wetlands
View the document2.4 Wastewater treatment using duckweed
View the document2.5 Wastewater treatment using lagoons
View the document2.6 Other technologies of wastewater treatment and reuse
close this folder3. Freshwater augmentation
View the document3.1 General rainwater harvesting technologies
View the document3.2 Rainwater harvesting for drinking water supply
View the document3.3 Rooftop rainwater harvesting for domestic water supply
View the document3.4 Rainwater harvesting for agricultural water supply
View the document3.5 Rainwater harvesting for irrigation water supply
View the document3.6 Rainwater harvesting for community water supply
View the document3.7 Rainwater harvesting for multiple purpose use technical description
View the document3.8 Open sky rainwater harvesting technical description
View the document3.9 Rainwater harvesting in ponds
View the document3.10 Artificial recharge of groundwater technical description
View the document3.11 Fog, dew and snow harvesting
View the document3.12 Bamboo pipe water supply system
View the document3.13 Hydraulic ram technical description
View the document3.14 Development and protection of natural springs
View the document3.15 Restoration of traditional stone spouts
close this folder4. Upgrading water quality
View the document4.1 Desalination
View the document4.2 Pond sand filtration
View the document4.3 Biological pretreatment of raw water
close this folderPart C - Case studies
View the document5.1 Water conservation and recycling - Gujarat State fertilizer corporation, India
View the document5.2 Traditional methods of soil and water conservation - coconut pick-ups, India
View the document5.3 Use of reclaimed water - Hindustan petroleum corporation limited, India
View the document5.4 Reclaimed city sewage as industrial water - Madras fertilizers limited, Madras, India
View the document5.5 Rainwater harvesting - the Thai rainwater jar
View the document5.6 Daungha rainwater collection water supply project, Nepal
View the document5.7 Conjunctive use of surface and groundwater - Krishna Delta, India
View the document5.8 Artificial groundwater recharge - India
View the document5.9 Integrated water conservation - Bhilai steel plant, India
View the document5.10 Drip irrigation - India
close this folderPart D - Annexes
View the documentAnnex 1 - Additional references
View the documentAnnex 2 - Table of conversion factors for metric and U.S. customary units
close this folderPart E - Institutional profiles
View the documentThe UNEP water branch
View the documentDanish hydraulic institute (DHI)

Annex 2 - Table of conversion factors for metric and U.S. customary units

This water quantity equivalents and conversion factor lists is for those interested in converting units. The right-hand column includes units expressed in two systems - US 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.

US Customary


US Customary or Metric

Length

1 in (inch)

=

25.4 mm (millimetres)

1 ft (foot)

=

0.3048 m (metre)

1 mi (mile, statute)

=

5280. ft


=

1,609.344 m


=

1.609344 km (kilometres)

Area

1 ft2 (square foot)


0.09290304 m2 (square metre)

1 acre

=

43,560. ft2


=

0.0015625 mi2


=

0.40469 ha (hectare)

1 mi2

=

640. acres


=

259.00 ha


=

2.5900 km2 (square kilometres)

Volume or Capacity (liquid measure)

1 qt (quart, US)

=

0.94635 l(litre)

1 gal (gallon, US)

=

231. in3 (cubic inches)


=

0.13368 ft3 (cubic foot)


=

3.78541


=

0.0037854 m3 (cubic metre)

1 Mgal (million gallon)

=

0.13368 Mft3 (million cubic feet)

1 Mgal

=

3.0689 acre-ft (acre-feet)


=

3,785.4m3

1ft3

=

1,728. in3


=

7.4805 gal


=

28.317 1


=

0.028317 m3

1 Mft3

=

28,317. M3

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 kilometres)

Speed (or, when used in a vector sense, velocity)

1 ft/s (foot per second)

=

0.3048 m/s (metre 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 (litres per minute)


=

0.063090 l/s (litres 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 metre per second)


=

3,785.4 m3/d (cubic metres per day)

1 billion gal/yr (billion gallons per year)

=

0.0013817 km3/yr (cubic kilometre per year)

1 ft3/s

=

2.7397 mgd


=

448.83 gal/min


=

0.64632 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


=

0.0013813ft3/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/mi2


=

27,154. gal/acre (gallons per acre)


=

25,400. m3/km2 (cubic metres per square kilometre)

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 runoff - per year)

1 (ft3/s)/mi2

=

13.574 in/yr


=

0.010933 (m3/km2 (cubic metre per second per square kilometre)

Mass (pure water in dry air)

1 gal at 15° Celsius (59° Fahrenheit)

=

8.3290 lb (pounds avoirdupois)

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, US Geological Survey (National Water Summary 1990-1991)