SIO15 2018: Lecture 12

Mass Movements in Southern California and Hazard Reduction

handout notes
POSTED: 17 October 2018

  • Five Random Review Questions (not a complete review!)

  • 1) Which of these is NOT a good descriptor of natural factors for slumping in Southern California?
    1. active plate boundary weakens crust
    2. occasional heavy rain causes erosion and reduces friction of slumping masses
    3. earthquakes trigger mass movements
    4. bedrock is ground up by frequent hurricanes
    5. semiarid climate causes sparse vegetation that would anchor soil
    2) Which of these does NOT describe how humans increase the risk of slumping in Southern California?
    1. steepening slopes of hillsides beyond angle of repose
    2. development on ancient landslide
    3. plant native, drought-resistant plants
    4. plant tropical plants that need artificial irrigation
    5. leaking pools and sewer systems
    3) Installing a septic tank instead of a draining sewer system on unstable ground .... the risk of slumping.
    1. increases
    2. decreases
    4) Which of these is NOT a good action to lower the risk of slumping?
    1. build retaining walls
    2. lower the slope of a hillside
    3. install drainage ditches
    4. remove dirt from the foot of a hillside
    5. plant deep-rooting, drought-tolerant trees
    5) What can lower the ground water table?
    1. excess farming
    2. installing drainage systems
    3. droughts
    4. all of the above
    5. only a) and b)

    Answers: 1d; 2c; 3a; 4d; 5d