Hello.
My name is Molly Wood, and I'm the Surface-Water Specialist for the Idaho Water Science Center.
Today I am going to review some best practices for using SWAMI to document site visits and
measurement information at index-velocity streamgages.
We hope that this guidance will improve consistency in field notes for index-velocity streamgages.
Ok.
So you are visiting an index-velocity streamgage and want to record field notes.
Open SWAMI.
On the first page, you'll enter basic site information.
For this example, I'm going to enter notes for an index-velocity streamgage on the St.
Joe River near St Maries, Idaho.
I'm going to select the gage from the pick list to the right of the Station Field.
Once I find and highlight it, I'll click Done.
You'll see that the site information has been populated.
Details on entering basic site information (such as weather) are covered in other screencasts,
so I'm going to skip to the Tasks window.
Click on Tasks in the lower right corner.
We are going to enter some information about the index-velocity meter (an acoustic Doppler
velocity meter or ADVM).
Click on Sensor Inspections.
Your ADVMs should already be loaded as site specific sensors through Site Visit and your
getsensors script.
Refer to other screencasts and tip sheets on configuring sensors in SiteVisit.
Highlight the Velocity Sensor, which is identified with parameter code 00055-Stream velocity
in ft/sec.
You'll note that in my case, the Sensor Name and Serial # are both set as "generic".
These are set as generic in SiteVisit, so I'm going to leave them as is so there are
no conflicts when uploading data to SiteVisit, especially if I ever exchange ADVMs at the
gage.
Note that in order for sensor information and readings from the SWAMI file to successfully
load into SiteVisit via the loader, the sensor setup information must match exactly between
SWAMI and SiteVisit for that particular gage.
We will first enter an index velocity reading from the ADVM, which will most likely be the
last recorded reading.
Click Readings.
Enter the time and value of the last index velocity reading.
For this example, my last recorded reading from the ADVM was at 11:45 and was 2.56 ft/sec.
Click Add, then Done.
Now we're going to enter additional information about the ADVM.
Again highlight the velocity sensor in the Sensor Inspections table and click Inspection.
Per OSW policy, we need to perform a temperature comparison with the thermistor in the ADVM.
Let's first enter notes about the temperature readings from your ADVM thermistor and a comparison
temperature probe.
It's important that the comparison temperature reading be made close to your ADVM, and the
two temperatures must match within 2 degrees C per OSW Memo 2010.07.
I did my temperature comparison next to the ADVM and I'm going to write "Comparison temp
at 11:50: ADVM 15.5 deg C; temp probe 15.7 deg C".
If your index-velocity streamgage is in an area affected by saltwater, you'll also need
to note salinity measurements here and notes about comparison against what's currently
configured in the ADVM.
For example, I'm entering "Salinity reading = 10.2 ppt.
ADVM configured for 10 ppt - ok".
You'll also want to use the Sensor Inspection comment field to record comments about things
such as: Beam checks: whether they were performed and whether any problems were noted.
For example, I'm going to write "Ran beam check at 12:00 - all ok".
Next, whether the ADVM was cleaned.
For example, I'm going to write "Cleaned small amount of algae from transducers at 12:05.
Ran another beam check at 12:10 -- all ok, no change" Next, whether the internal ADVM
recorder was downloaded and document the file name.
I'm going to write downloaded ADVM recorder file: 12415135_the date.arg which is the name
of the file.
Next, what the clock reading was on the ADVM and whether it needed to be adjusted (and
if so, by how much).
I'm going to write, "ADVM clock 38 seconds slow.
Reset at 12:15:20."
Click Done to return to the Sensor Inspections Table.
You'll also want to add other sensor inspections (such as gage height) as you normally would
for any streamgage.
Details of these entries are covered in other SWAMI screencasts, so we won't go through
them here.
For now, click Done again to return to the Site Visit Tasks window.
Now I'm going to stage a discharge measurement in SWAMI and will later import my measurement
file.
Details of staging and uploading a measurement in SWAMI are covered in other screencasts,
so I am going to skip ahead to cover what should be documented for measurements at index-velocity
sites.
According to USGS Techniques and Methods Report 3-A23, "Computing Discharge Using the Index
Velocity Method" (shown here) you should increase the index velocity measurement frequency during
discharge measurements, preferably to 1 minute intervals.
I'm going to do this and then go make my discharge measurement.
After I'm done with the discharge measurement, I'll be sure to set my index velocity measurement
frequency back to its regular configuration.
Ok.
Now that I've finished my discharge measurement and imported my measurement file, I'm going
to verify the information in my ADCP measurement summary.
Note that all of these fields are specific to the ADCP measurement.
Do not replace fields like Area and Mean Vel with those from your index-velocity rating.
We will document this information later.
Click Done, then Done.
SWAMI currently cannot pull ratings and calculate rated Q for index-velocity sites.
You'll need to calculate rated Q outside of SWAMI and enter the information.
In the Discharge Measurement window, click Done and then Yes when prompted to end the
discharge measurement.
In this window, the Remarks field is very important.
You will use this field to document your rating information.
After I finished my discharge measurement, I downloaded my 1-minute velocity data and
my 15-minute stage data collected during the measurement.
Using the data synchronization rules specified in the Index-Velocity Techniques and Methods
Report 3-A23, I calculate my average index velocity and gage height for my measurement.
Based on my index-velocity and stage-area ratings, I calculate rated Q in the field.
In the Remarks field, I enter "Avg IV = 2.65 ft/sec.
Rated Vmean = 2.45 ft/sec.
Rated Area = 6620 sq ft.
Rated Q = 21900 cfs.
Diff from rated = -1.1 %." I also enter my average stage reading for the measurement,
5.69 ft, and note any stage change during the measurement.
I want to point out that it is very important to calculate rated Q and compare to your measurement
while you are in the field, in case a check measurement is needed.
It is also important to document this comparison so that others understand what you did and
why.
We realize this is a little more difficult and time consuming at index-velocity gages
than at stage-discharge gages since the computation is currently not automated in SWAMI.
However, it is required per OSW policy.
We hope to soon modify some existing index-velocity rating and synchronization tools to make this
easier and quicker in the field.
When finished, click Done, then Done again.
Let's go back in the Sensor Inspections task and enter the last recorded velocity reading
from your ADVM.
In Site Visit Tasks, select Sensor Inspections.
Highlight the velocity sensor and click Readings.
After my measurement, the ADVM recorded an index velocity reading at 13:00 of 2.72 ft/sec.
Click Add then Done.
There is no need to enter all of the index-velocity readings collected during your measurement
(particularly 1-minute velocity data) as long as the data are archived elsewhere -- in ADAPS
or in your data archival structure with your measurement files.
If DCP readings or transmissions are missing from the period of time you were at the site,
then it's very important to upload the downloaded data as soon as you get back to the office.
Click Done, then Done.
That covers the key information that needs to be documented in SWAMI for a site visit
to an index-velocity streamgage.
Guidance on using SWAMI to document other information needed for all streamgages is
provided in other screencasts.
You can also contact the SWAMI help group or visit the FCIS webpage.