This topic contains a solution. Click here to go to the answer

Author Question: Why would building a levee from locally-available material make it susceptible to failure? What ... (Read 69 times)

joesmith1212

  • Hero Member
  • *****
  • Posts: 549
Why would building a levee from locally-available material make it susceptible to failure?
  What will be an ideal response?

Question 2

Describe coastal effects of removing sediments from a stream, as is done during mining.
  What will be an ideal response?



Related Topics

Need homework help now?

Ask unlimited questions for free

Ask a Question
Marked as best answer by a Subject Expert

Dunkey

  • Sr. Member
  • ****
  • Posts: 333
Answer to Question 1

ANSWER: The floodplain materials on which levees are built are often composed of old permeable sand and gravel channels surrounded by less permeable muds. The floodplain muds beyond the current channel are sediments that were left behind by the river where it spilled over a natural levee to flow on the floodplain. A river migrates across all parts of that floodplain over a period of hundreds or thousands of years. Under a mud-capped floodplain, the broad layers of sand and gravel deposited in former river channels interweave one another. These permeable layers provide avenues for transfer of high water in a river channel to lower areas behind levees on a floodplain. If a flood is prolonged, seepage beneath the levee can transmit enough water to flood surrounding areas behind the levee.

Answer to Question 2

ANSWER: Removal of sediments from a stream often has consequences far from the site of removal, where a river deposits its sediment at the coast. Normally, much of the sediment deposited in the river delta is carried up or down the coast by longshore drift. When the sediment supply is reduced because of gravel mining or an upstream dam, the longshore movement of sediment along the coast continues but is not replenished. Beaches erode and may even disappear. Waves that normally break against the beach then break against the beach-face dunes or sea cliffs, causing severe erosion.




joesmith1212

  • Member
  • Posts: 549
Reply 2 on: Jul 13, 2018
:D TYSM


epscape

  • Member
  • Posts: 335
Reply 3 on: Yesterday
Thanks for the timely response, appreciate it

 

Did you know?

Malaria was not eliminated in the United States until 1951. The term eliminated means that no new cases arise in a country for 3 years.

Did you know?

Computer programs are available that crosscheck a new drug's possible trade name with all other trade names currently available. These programs detect dangerous similarities between names and alert the manufacturer of the drug.

Did you know?

Though Candida and Aspergillus species are the most common fungal pathogens causing invasive fungal disease in the immunocompromised, infections due to previously uncommon hyaline and dematiaceous filamentous fungi are occurring more often today. Rare fungal infections, once accurately diagnosed, may require surgical debridement, immunotherapy, and newer antifungals used singly or in combination with older antifungals, on a case-by-case basis.

Did you know?

When blood is exposed to air, it clots. Heparin allows the blood to come in direct contact with air without clotting.

Did you know?

Though newer “smart” infusion pumps are increasingly becoming more sophisticated, they cannot prevent all programming and administration errors. Health care professionals that use smart infusion pumps must still practice the rights of medication administration and have other professionals double-check all high-risk infusions.

For a complete list of videos, visit our video library