Open book, open notes. Answer only ten (10) questions.

  1. Why do natural streams carry sediments? What mechanical process enables sediment entrainment and transport? What are typical values of bed material sediment concentration in natural streams? What is wash load?

  2. Describe the criterion describing initiation of motion in natural streams. What is the typical value of Froude number that guarantees initiation of motion?

  3. What parameter describes the relation between critical bottom shear stress and critical mean velocity?

  4. What is autodredging? Where does it occur? How does it occur? What is the ecological benefit of autodredging?

  5. How may a river profile (bottom slope profile) be used as an indication of changes in sediment transport? In the absence of geologic controls, what is the typical shape of a stream/river profile? Why?

  6. How does tectonism and the enduring presence of the oceans combine to assure the process of soil sedimentation and consequent valley formation?

  7. Explain the relation between the existence of forests, floods, and springs. What was Humboldt's major contribution to science?

  8. Explain the factors that lead to the meandering of rivers. To what did Albert Einstein attribute the cause of meandering? Is river straightening a solution to river meandering?

  9. What distinctive geologic event led to the formation of the Colorado Desert, later renamed Imperial Valley? What geologic feature assured the existence of the Salton Sea, which would later be used as a repository for agricultural drainage?

  10. Why a clearwater stream/river hungry for sediment? Explain in detail. What is the only parameter in the Modified Lane relation to be determined empirically?

  11. Bonus question (may be used to replace any of the above): Is sediment a blessing, or a curse? How does sediment affect human societies? Give examples. What is the preferred way to approach sediment management?