Scientific Investigations Report 2005-5227

U.S. GEOLOGICAL SURVEY
Scientific Investigations Report 2005-5227

# Conversion Factors and Datums

## Conversion Factors

Multiply By To obtain
acre-foot (acre-ft) 1,233 cubic meter
acre-foot (acre-ft) 0.001233 cubic hectometer
cubic foot per second (ft3/s) 0.02832 cubic meter per second
foot (ft) 0.3048 meter
foot per day (ft/d) 0.3048 meter per day
foot per mile (ft/mi) 0.1894 meter per kilometer
foot per second (ft/s) 0.3048 meter per second
foot per year (ft/yr) 0.3048 meter per year (m/yr)
foot squared per day (ft2/d 0.09290 meter squared per day
gallon (gal) 3.785 liter
gallon (gal) 0.003785 cubic meter
gallon per day (gal/d) 0.003785 cubic meter per day
gallon per minute (gal/min) 0.06309 liter per second
inch per year (in/yr) 25.4 millimeter per year
mile (mi) 1.609 kilometer
cubic mile (mi3) 4.168 cubic kilometer
square mile (mi2) 2.590 square kilometer
million gallons (Mgal) 3,785 cubic meter
million gallons per day (Mgal/d) 0.04381 cubic meter per second

Temperature in degrees Celsius (°C) may be converted to degrees Fahrenheit (°F) as follows:

°F=(1.8×°C)+32.

## Datums

Vertical coordinate information is referenced to the National Geodetic Vertical Datum of 1929 (NGVD 29).

Horizontal coordinate information is referenced to the North American Datum of 1927 (NAD 27).

Altitude, as used in this report, refers to distance above the vertical datum.

Transmissivity: The standard unit for transmissivity is cubic foot per day per square foot times foot of aquifer thickness [(ft 3/d)/ft2]ft. In this report, the mathematically reduced form, foot squared per day (ft2/d), is used for convenience.