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river readings

Started by Bloy, December 28, 2006, 08:40:22 AM

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Bloy

I'm trying to educate myself on stream data.    o-o    Given the following data, how do I determine what might be high, low or normal?

http://waterdata.usgs.gov/nwis/nwisman/?site_no=02112360&agency_cd=USGS

Barry

Times fun when you're having flies.
...Kermit

troutphisher

December 28, 2006, 09:12:42 AM #1 Last Edit: December 28, 2006, 09:17:19 AM by troutphisher

Barry:

On that same site, there is more data. Look at the graphs of flow rate.
There is an annual and historical flow rate.

This will give you an indication of the current flow rate data, compare current to average.

http://waterdata.usgs.gov/nc/nwis/uv/?site_no=03441000&PARAmeter_cd=00065,00060

I set this up for the Davidson river, by county. you can see from the graphs, the mean daily average.
you can change the data request to get other info aslo.

The object of life is not to be on the side of the majority, but to escape finding oneself in the ranks of the insane.

phg

I think what you are looking for is the Real-time graph (first choice).  It shows that normal flows are between 100 (median) and 115 (mean) cf/sec.  Right now it's running at 155, which is a bit high, about 50% more water than usual, but, checking the chart below, only an additional 4" of depth.  Definitely fishable.

As my dad used to say, "She's running a bit high and swift, just be careful."


Bloy

Quote from: troutphisher on December 28, 2006, 09:12:42 AM

This will give you an indication of the current flow rate data, compare current to average.

Is the 'flow rate' the same as the 'Discharge / cfs'? Precisely where is the 'current to average' reading?I'm still trying to make sense of this? Thank you for your assistance.

Barry

Times fun when you're having flies.
...Kermit

troutphisher

Barry:

Yes, the flow rate is in CFS (cubic feet per second). It is the blue line that appears on the graph (Titled Discharge). You will see high and low curves. The curve in the example I made above, was graphed to show the days...ie Dec 21,though Dec 28.

The Yellow triangles, are the historical data, also in CFS, this is data collected over a longer period, again in the case above it is over the last 82 years.

The table below is a daily statistical mean (fancy word for average) compared to the same 82 year historical data.

The graph below the table is a gage height graph, this graph shows the water levels. In this case the water is up 1.3ft above normal flow, another indication the water flow is good, higher than normal.

All this information is based on the dates shown, you can check this again tomorrow to see if there are any changes.

The object of life is not to be on the side of the majority, but to escape finding oneself in the ranks of the insane.

Bloy

Quote from: troutphisher on December 28, 2006, 21:27:50 PM

In this case the water is up 1.3ft above normal flow

Where on the chart do you determine the 'normal flow'.

Barry

Times fun when you're having flies.
...Kermit

troutphisher

The horizontal Axis (X) has the datum point 0,0. That is the normal flow.
Any graph lines above this horizontal line, are above mormal flows. If the graph
lines are below 0,0. Then the water flow is below normal.

The gaging station is where they collect the flow data. It is measured by the following: 1ft x 1ft sq, 1ft deep. Think of a 3 dimensional box.

The water is measured by volume through this box, and the flow rate is then given as cf (cubic feet). The amount of water that passes through 12" x 12" x 12".

Becuase the water travels a distance of 12", there is a time period for this to happen. The time period is given in seconds 1/60 of a minute or 1/3600 of an hour. The equation now becomes Volume/ft X time/sec = cubic Feet sec.

One "CFS" is equal to 7.48 gallons of water flowing each second.

The object of life is not to be on the side of the majority, but to escape finding oneself in the ranks of the insane.

Woolly Bugger

ex - I'm not going to live with you through one more fishing season!

me -There's a season?

Pastor explains icons to my son: you know like the fish symbol on the back of cars.

My son: My dad has two fish on his car and they're both trout!

Bloy

Quote from: trout-r-us on December 29, 2006, 15:46:15 PM

Even I can understand it when you show me a picture.

All of a sudden I don't feel so dumb anymore.   ;D ;D ;D

The Don't Fish & the Go fish pretty much straightens me out.

Thanks fellows !! Class dismissed.  ;)
Barry

Times fun when you're having flies.
...Kermit


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