GEOL105 Lecture Notes - Lecture 11: Thunderstorm, Big Thompson River
22 Mar 2017
School
Department
Course
Professor
Document Summary
Rising and falling river may create natural ones. Artificial ones are built in many location as a primary flood control device. During hurricane katerina, it was the levees that failed. Aim is to store excess water and release more slowly. May be small dams on tributaries that only stop flow during flood danger. Or big dams also used for power and/or irrigation. Sometimes they will breach a levee to lessen the pressure. Development will cause more runoff, increasing the risk of floods: particularly flash floods. Downstream flood example: 1993 mississippi - missouri river floods. Reason for the flood: the precipitation 400-750% above normal after wet winter. About 50 lives lost, billion in damage. All the levees by the government/federal held throughout the flood however the locally and sate created ones failed. Flash flood example: 1976 big thompson canyon flood.
