(warm tone playing)
- [Narrator] For too long, researchers have had to rely
on old data when determining flood estimation across Texas.
This project, headed up by
the Texas Tech Center for Multidisciplinary Research
in Transportation was designed to update the Texas
generalized skew map for the Texas Department
of Transportation Hydraulic Design Manual.
- The map that we have in the HDM right now
was produced in 1996, right?
And so it was based on older record and
a smaller record.
So the greater the record you have,
the more accuracy you have.
- [Narrator] Researchers utilized 30 years of unused data,
which will likely open the door
for future statistical research into
Texas, Oklahoma and Eastern New Mexico flood hydrology.
- New technologies have become available
in the last 15 years.
And quite a bit of recent data has become available
in the flood frequency arena.
And that's important
for transportation infrastructure design
in particular bridges, culverts, roadways
and associated drainage infrastructure.
- Those skew values are used in developing a gauge analysis.
And so what a gauge analysis is,
is really just taking a distribution
and a population of flow rates,
annual flow rates, peak flow rates,
and fitting a curve to it.
And that curve shape is changed
based on what region you're in Texas with the skew.
And so it can trend up.
It can trend down.
- The information we used are stream flow records
that are stored by the United States geological survey
for Texas specific stations
and included Oklahoma, parts of New Mexico, Louisiana.
Also, those skew values should not abruptly change
just because you crossed the state line.
So we need to have the adjacent states
to help inform our analysis.
And from that, we create a probability model
of the behavior of the flood recurrence
at particular locations.
And we found that the skew values for the state,
incorporating new data,
have changed somewhat from the last time this was done.
And the impacts of those modified skew values
are fairly important along the coastal bend
and the coastal plains of Texas,
somewhat in the hill country
and less so out here in West Texas.
- And so if you look at the two maps
and put them side by side, there's better resolution too.
There's less gaps between the contours.
So there's less averaging or interpolation.
So now you're getting better accuracy with your flow rates.
So if you're overestimating your flows,
your bridges will be bigger, right?
So we're spending more money on our bridges.
If you underestimate, that translates into a safety issue
or a reliability issue.
So we want to be as accurate as we can.
We don't want to overestimate.
And we don't want to underestimate
- [Narrator] For more information
and to find the publications for this project,
please visit the text dot research library
at the link shown below.