a Parshall Flume and who invented it?
A Parshall flume has a special shaped open
channel flow section which may be installed in a ditch
,canal, or lateral to measure the flow rate. The Parshall
flume is a particular form of venturi flume and is named
for its principal developer, the late Mr. Ralph L. Parshall
(Water Measurement Manual, U.S. Bureau of Reclamation,
Ralph L. Parshall saw problems with stream measurements
when he began working for the USDA in 1915, as an irrigation
research engineer. In 1922 he invented the flume now
known by his name. When this flume is placed in a channel,
flow is uniquely related to the water depth. By 1953
Parshall had developed the depth-flow relationships
for flumes with throat widths from 3 inches to 50 feet.
The Parshall flume has had a major influence on the
equitable distribution and proper management of irrigation
Parshall flumes are apparently the most widely used
types of flumes now for fixed flow monitoring installations.
They have wide flow ranges, resistance to submersion,and
are simple to calibrate..
Parshall flumes are sized by throat width and conform
to standardized dimensions published in the U.S. Department
of the Interior, Bureau of Reclamation.
Whole books have been written about Flumes and Weirs.
Nowadays there are several types of popular flumes to
choose from including the Palmer-Bowlus, Trapezoidal,
HS/H/HL-Type, Cutthroat, RBC, Montana, and SANIIRI and
plenty of custom flumes. Computer simulation software
has been written to assist people in designing optimum
flume types and computer assisted calculations assist
many engineers (some of whom may not be aware of the
technical implications) in designing Flumes and open