Steve Markstrom: Welcome to the PRMS training video on the time series data process.
This is not really a hydrologic process but more of administrative task that PRMS does.
Basically it's got to read data from a data file, and we do have a module...PRMS has a
single module that does that.
It's called the OBS Module.
Here you can see a cut-out of table one four from the PRMS users menu, and this part of
the table shows all the different input variables that could be included in the data file.
You can see there's quite a bit of them.
The normal values that are in the data file are precipitation, stream flow data, daily
maximum and minimum temperature.
Those could be typically included in the data file.
It's going to be discussed much more in the climate process presentation.
Some of the rules about dealing with this stuff is that there must be a data file because
PRMS uses the dates, the time steps in the data file, to actually drive the time loop
so you have to have a data file.
The data file must include time steps that include the period that you want to run the
model for.
You can't run the model outside of time steps that are included in the data file.
The data file typically contains a station data and the climate-by-HRU file or the CBH
file, which again will be discussed later, typically contains time series data by HRU.
That's kind of the distinction.
Both the data file and the CBH files can contain climate data.
OK, here is a little example of the PRMS data file.
Again this comes from, this image here comes from the PRMS user's manual, but what I think
I'm going to do here is just pop open a text editor, and here you can see I've actually
loaded in the ACF data file from the example.
Here we can see this very first line is a comment or is the tag describing the source
of the data, in this case created by downsizer.
Then any line that starts with two slashes like that is a comment, and in this case what
we've done is comment the source of the data down below.
This is a station data, you can see the station ID and then the latitude, the longitude, and
the elevation of the station.
In this case it says, air temperature maximum so you can see we've got quite a few values
of maximum air temperature, then it's air temperature minimum.
Again, these are comments.
Then we've got stream flow data in here, so this is the gauge ID and latitude and longitude.
This stuff here basically tells you how many columns of each value type you're going to
have.
OK, so this says we have 79 TMAX, 79 TMIN, 79 precipitation, and then 58 stream flow
values.
This line here delineates the header part from the actual data down here, and then you
could see the data starts.
And here's the time stamp: year month day, hour, minute, second.
You can see the data for that day goes out on the line.
You can see this is a pretty long lines, -999 is our missing value.
This goes from the end of 1949 out to sometime in 2009.
OK, so that is a typical data file, and with that I will conclude this presentation.