Ecohydrology - Week 8 - Flood Hydrology

1. What is the definition of a flood according to Hewlett (1982)?

• A. Any fast water flow in a river
  

• B. Water that moves quickly
  

• C. Water that overflows normally dry land
  

• D. A pond near a forest
  

2. What caused the St. Francis Dam disaster in 1928?

• A. Earthquake
  

• B. Heavy rain
  

• C. Poor site geology and construction flaws
  

• D. Human sabotage
  

3. Which type of flood is triggered when peak flows from different sub-basins combine in the main river?

• A. Rain-on-snow flood
  

• B. Tributary convergence flood

• C. Channel over-spilling flood
  

• D. Tidal backflow flood
  to rivers

4. What concept explains runoff from only a small portion of a catchment contributing to streamflow during early rainfall?

• A. Hortonian Overland Flow
  

• B. Variable Source Area
  

• C. Storm Drain Overflow
  

• D. Baseflow Recharge
  

5. Which condition is most likely to produce saturation overland flow rather than Hortonian overland flow?

• Rainfall intensity briefly exceeds infiltration rate on dry soil
  

• Flash flood in arid region after drought

• Short rainstorm on steep slopes
  

• Soil is fully saturated from previous rain and cannot absorb more
  

6. What is the primary mechanism for cloudburst flash floods?

• Rainfall intensity exceeds infiltration (HOF)

• Rising groundwater table
  

• Channel blockages by debris

• Rain plus rapid snowmelt in warm weather

7. What is the annual exceedance probability of a 20-year flood?

• A. 2%
  

• B. 5%
  

• C. 80%

• D. Depends on the flood predictability

8. What issue most contributes to urban stormwater drain floods in coastal cities like Port Phillip?

• Deep groundwater recharge

• Overbuilt riverbanks

• Loss of vegetation cover
  

• Old drainage systems and rising sea levels

9. What is the expected effect of sea level rise on flood exceedance probabilities by 2100 in Port Phillip?

• A. Flood probabilities will decrease due to better forecasting
  

• B. A 100-year flood may occur every 1–2 years
  

• C. Sea level rise will not affect flood frequency
  but flood intensity

• D. Only 100-year inland floods will become more frequent
  

10. According to the Natural Flow Regime Paradigm, which of the following is not directly a component of flow regime?

• A. Magnitude
  

• B. Timing
  

• C. Catchment size
  

• D. Predictability