- You have been reassigned to head up the Fargo, North Dakota office of your company, Denyallclaims Insurance, Inc. You are aware that in 2011 the Red River of the North, which
runs through Fargo, crested near the highest level recorded in this century, and you are
concerned about buying property and living in the area of Fargo. One of your friends has an brother-in-law who has a cousin that lives in Fargo, who assures you that while
flooding was severe in 2011, this was a 200 year flood, and such a flood will not occur
for another 200 years! You know from taking a natural disasters
class that his statement is
hogwash, so you decide to check out the discharge history of the Red River in Fargo on the
internet. Because you took a course in natural disasters, you know that if you visit
the web site of the U.S.G.S. Water Resources Division:
http://water.usgs.gov/nwis/
you can obtain discharge data from thousands of gaging stations throughout the United
States. Go to this web site and do the following:
On the upper right-hand side of the page are boxes that you can set to
take you more directly to the information you want. Under the line
that says "Data category", use the down arrow next to the box
to change the box to read "Surface Water".
Under the line that says "Geographic Area", use the down arrow
next to the box to change the box to read "North
Dakota". This
will take you to the North Dakota surface water page.
Next, click on the button that says "Daily Data" from the
selection of buttons on the left-hand side of the page. This will take
you to the Daily Streamflow for North Dakota page. Here we need to
specifically search for the Data we want. To make things simpler, I
have provided you with the station number of the gaging station in Fargo.
This is 05054000. So put a check mark in the box next to
"Site Number" and remove the check mark in the box next to "Site Type",
then click on the Submit button.
On the page that comes up, there is a box into which you should enter
the Site Number - 05054000 and click on the dot
next to "exact match". Under "Available Parameters,
put a check mark in the box next to "Streamflow ft3/s", Now scroll down and
make sure the "Table of Sites Sorted by Hydrlogic unit" is selected.
Scroll down and under "Retrieve USGS Surface-Water Daily Data for Selected
Sites" select the date range from a First date of 1983-07-31
to a Last date of 2013-08-01. Then Scroll down further and under "Output Options" make sure "Graphs of Data"
is selected and that there is a check mark in the box next to "Use
arithmetic Y-axis for discharge". Now click on the "Submit"
button. A page with a table and a graph should load. Scroll
down and look at the graph. It should have the title "USGS 050504000
RED RIVER OF THE NORTH AT FARGO, ND" If it doesn't have this title,
go back and start again. The graph appears near the bottom of the
page. You might want to print this graph for later use in answering
questions (a) and (d), below.
- The graph shows mean discharge on a daily basis versus time for the 30 year
period. Look at the graph. Floodstage for this gaging station is about
4100 ft3/sec. Over this 30 year period, how many times has the Red River
exceeded flood stage (note that each peak in the data represents
a separate event)? In what year did the highest discharge occur, and what was the
value of that discharge? (2 points)
- Notice that there seems to be a periodicity to where the peaks of high discharge occur
on the hydrograph (that is the distance between peak discharge points are approximately
equally spaced). In order to better understand what may be the cause of this
periodicity, and perhaps the cause of the flooding, we want to
look at the data over a shorter period of time. Use the Back
button on your web browser to return to Site Selection Page and ask to retrieve data over a
shorter period of time (10 years), this time use range between 1992-01-01 to
2001-12-31. Click on the "Submit" button again, and on the page that loads,
scroll down to look at the graph that is
eventually displayed. What is your best estimate the approximate month or months in which
the peak discharge occurs in each year of this 10 year period? Knowing that North
Dakota is in the northern part of the United States, why do you think that the peak
discharge occurs in this month or range of months? (2 points)
- To find out more about floods on the Red River of the North go to the
Fargo Flood
Home Page:
http://www.ndsu.nodak.edu/fargoflood/
then page down and select the link - "Flood Information for
Fargo".
Now answer the question - What makes the Red River Valley so prone to flooding?
(2 points)
- Is there any information at this web site that suggests that any major floods have occurred at Fargo in the past 30 years? If so, when
were these flood and how severe were they? (Note: to answer
this question, you might
want to consult flood hydrographs for prevous major floods, and the graph you
printed earlier, and compare them with each other and to the flood
frequency diagram for the Red River at Fargo that appears in your
lecture notes -
http://www.tulane.edu/~sanelson/geol204/floodhaz.htm). (1 point)
- What precautions should you take in choosing your home and home site
in the Fargo area if
you decide to move there to head up the Denyallclaims office in Fargo?
Is there any information or links on the Fargo Flood Home Page that
would help you in making this decision? If so, describe any
information that is available.(2 points)
- From what you have learned by visiting the web sites for this
assignment, how to you respond to your friend's brother-in-law's cousin who said that severe
flooding would not occur for another 200 years? (1 point)
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