Conversion Factors and Datums

Conversion Factors

Inch/Pound to SI

Multiply	By	To obtain
cubic foot per second (ft3/s)	0.02832	cubic meter per second (m3/s)
foot (ft)	0.3048	meter (m)
inch (in.)	2.54	centimeter (cm)
mile (mi)	1.609	kilometer (km)
square mile (mi2)	2.590	square kilometer (km2)

SI to Inch/Pound

Multiply	By	To obtain
liter (L)	0.2642	gallon (gal)
milliliter (mL)	0.033814	ounce, fluid (fl. oz)
millimeter (mm)	0.03937	inch (in.)

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

°F=(1.8×°C)+32.

Specific conductance is given in microsiemens per centimeter at 25 degrees Celsius (µS/cm at 25 °C).

Concentrations of chemical constituents in water are given either in milligrams per liter (mg/L) or micrograms per liter (µg/L).

Datums

Horizontal coordinate information is referenced to either the North American Datum of 1927 (NAD 27) or 1983 (NAD 83) as noted in the text.

Abbreviations and Acronyms

BCF	bias corrections factor
Ci	concentration from a depth- and width-integrated sample
Cp	concentration from a pumped sampler
Cs	ambient stream concentration at the point of intake
CWS	Clean Water Services
E. coli	Escherichia coli
FNU	formazin nephelometric units
NWIS	National Water Information System
OWRD	Oregon Water Resources Department
ORWSC	U. S. Geological Survey Oregon Water Science Center
R2	coefficient of determination
RMSE	root mean square error
SRS	standard reference samples
SSC	suspended sediment concentration
TMDL	Total Maximum Daily Load
TKN	total Kjeldahl nitrogen
TP	total phosphorus
TSS	total suspended solids
USGS	U.S. Geological Survey
VIF	variance inflation factor
VIFcrit	critical level for VIF calculated from the model’s adjusted-R 2

First posted June 18, 2010