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| Randy Host and Pilot Dave Galla, with their
Cessna, on a river in Alaska. The ADCP's red endcap can be seen on the float between
the plane's pontoons. Any moment, they'll hop in the cockpit, and begin taking
measurements across the river. No perpendicular, straight-line path is required with the
Workhorse Rio Grande ADCP. |
24 hours versus 1 hour. Take
your pick. No phones, no bikes no motorcars. The USGS in Alaska has it tough!
They are required to chart river flows in some of the toughest wilderness areas on the
planet.
Trust them to come up with a simple solution. Since they
need a plane to access remote areas anyhow, they decided to use the plane as a boat, too!
Now, two USGS stream gaugers fly in to a river in a remote area with a small Cessna
airplane. After landing, they hang a Teledyne RDI
Workhorse Rio Grande ADCP between the pontoons of the plane and measure the
river by taxiing the ADCP from river bank to river bank for several complete
readings. Then they pack the instrument up and fly back out with the data! Total time from
takeoff to landing is about 60 minutes. Several rivers can be measured within a day.
Randy Host of the USGS Juneau Field Office explained how
the USGS used to measure the Stikine River, Station No. 15024800. Stream gaugers used to
take several steps to measure this one location: fly to a airport near the river, bring a
boat out from storage, drive a motorboat up the river at high tide (to clear the sandbars)
for about 2 hours, camp overnight, gauge the river the next day, then drive out again
after waiting once more for high tide. These trips could take over a full day to complete.
Randy prefers the plane, saying, "If the weather is changing fast, is sure is nice to
go get the work done quickly and get out of there."
The difference in logistics is considerable. The new
method takes about an hour rather than a day or more when compared to the old. The
transport of boats to remote locations is no longer required once the plane has a simple
instrument mount added. Stream gaugers are safer with the flexibility of the airplane that
shortens field work time. These advantages add up -- the Stikine River, our example, is
measured every 2 months, year round.
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