We can use a staff gauge to get the information
in an indirect way to calculate the stream flow. If we place the staff gauge
near a section of stream for which you are collecting flow data, you can
identify the corelation between stream depth & stream flow. Once you got
this relationship so we can calculate flow from the stream depth without having
to take a time to make a detailed flow measurement. A staff gauge having
numerically labeled divided in lines to take the measurement of water &
calculate easily the depth & stream flow.
USE STAFF GAGE
The staff gage is a long ruler placed half-permanently
in a stream or lake used to measure the water depth. Staff gages are the most useful & common for measurement. place the
staff gages in a lake. Place the three staff gauges because in mid portion the
lake water velocity is different as compared to the side of lake. There is some
resistance at the side of lake that’s why we place the multiple staff gauge. If
a staff gages place on non-vertical place so knowing that the staff gauges
reading is correct or not.
USING A STAFF GAGE
Velocity (ft/sec) by the cross-sectional area (ft.) of the stream.
5. Now calculate the discharge in
cft/second & multiply the
the mid-depth of stream velocity by multiply the surface velocity by 0.85.
we will determine the velocity by which the distance covered by float divided
by the average amount of time it taken to cover the distance. If the distance is 50 feet and the time
covered by a float/orange 100 seconds so get the velocity is 0.5 feet/sec.
The Float in the stream and record the time it takes by using stop watch to
reach the downstream. If the float moves too fast so record the data 75 or 100
instead of 50 feet. Now repeat the process two more times for a total of three
Total Width ft x Average
depth ft = area (ft).
the total stream calculate the cross-sec area of the stream on the both ends.
To find the total stream width and the average depth.
Measure the distance up to 50 feet along the
The main idea is to Measure the time that it
takes a floating object to travel a specified distance in stream downstream. You
can compute the flow of stream. Flow is important because define the size,
shape and direction of the stream.
If a Flow Meter is not Available or Rough
Estimate is enough so you can use the float to determine the flow. The float
can be any light object such as non submergible or an orange or partially
filled plastic bottle.
objects such as orange
3) Meter stick To Measure Depth (Tape Measures
are not possible to use)
or mobile phone having a timer
Determination the velocity & discharge using floats