Exercise 2 - Simonton Problem
Exercise 2

Land Erosion Along the Brazos River Near Simonton

    Multiple choice  




    The scale on this map is approximately 5 cm = 1 km (5 centimeters = 1 kilometer). Carefully lay a plastic ruler on the screen to measure the distance of the neck of land between the Bend in the Brazos.

    What is the width of the neck of land between the Bend in the Brazos in kilometers?

      about 2 km
      about 1 km
      about 0.5 km

    What is the width of the neck of land between the Bend in the Brazos in miles?

      about 0.5 miles
      about about 1 mile
      about about 2 miles




    The scale on this map is approximately 5 cm = 1 km (5 centimeters = 1 kilometer).

    What is the width of the neck of land between the Bend in the Brazos?

      about 1 km
      about 2 km
      about 800 meters feet

    From 1958 to 1977 the width of the neck of land between the Bend in the Brazos decreased by about

      about 200 meters
      about 400 meters
      about 200 feet

    The rate of erosion from 1958 to 1977 is about

      about 10 meters
      about 10 meters/year
      about 10 feet/year




    he scale on this map is approximately 5 cm = 1 km (5 centimeters = 1 kilometer).

    What is the width of the neck of land between the Bend in the Brazos?

      about 1,000 meters
      about 500 meters
      about 500 feet

    From 1958 to 1991 erosion reduced the width of the neck of land by about

      about 750 meters
      about 500 meters
      about 1,000 meters

    From 1958 to 1991 the rate of erosion was about

      about 20/metersyear feet
      about 15 meters/year
      about 10 meters/year feet

    Approximately how more year will take for erosion to cut completely through this neck of land?

      about 50 years
      about 33 years
      about 25 years

    [Your estimate should be considered a maximum. As the neck narrows, an increase in discharge may allow the river to rapidly cut across the narrowing neck. Thus, the frequency of major flooding and the rates of erosion are linked together.]

    An interim report by the U.S. Corps of Engineers suggests that flood-control levees might be feasible for at least some of the houses.

    Levee system A would protect 156 houses in sections II and III; levee system B would protect the remaining 39 houses in section I.

    Given projected costs, the Corps requires that the levee be designed to last for 50 years. As a concerned tax payer, you are asked to vote on a tax increase to raise funding to construct the levees. Based on your knowledge, how would you vote on the construction of Levee B?

      For the Proposition
      Against the Proposition

    How about levee A? This may be more feasible but note that levee A lies within the 100 year flood plain of the Brazos. Earlier you estimated that the 100 year flood would have a discharge of about 120,000.

    As a concerned property owner and tax payer, you must be involved in such decisions! Return