Floods Multiple Choice Questions and Answers

21. As the discharge in a stream increases, load usually

1. increases
2. decreases
3. stays the same
4. none of the above

22. A flash flood is a flood that Flood

1. is caused by heavy rain rather than from the flooding of a river
2. occurs in urban areas
3. occurs suddenly and unexpectedly and for a short duration
4. is caused by the blocking of drains

23. Which of these problems can be caused by floods?

1. Landslips
2. Sewage contamination
3. Destroyed crops
4. All of the above

24. Urbanization usually results in an increase in flood frequency because

1. less water is able to runoff in streams
2. less water is able to infiltrate into the ground,so instead is discharged rapidly i ntostreams
3. more water is used by humans and then discharged to streams
4. rainfall is greater in urban areas than in rural areas

25. In the future, which of the following is expected to increase the risk of flooding?

1. population growth
2. urbanisation
3. climate change
4. all of the above.

26. Dams are designed to reduce flooding by

1. protecting river banks from erosion
2. providing storage for flood water
3. increasing the downstream velocity of flood water
4. trapping sediment behind the dam so it cant be deposited downstream

27. What factors contribute to flooding?

1. Rainfall intensity
2. Rainfall duration
3. BOTH of the above; rainfall intensity and rainfall duration.

28. A flood can be caused by:

1. Rising rivers
2. High tides
3. Heavy rain in a small area
4. All of the above

29. Which of the following is used to estimate which areas will be inundated during a flood, based on river height information?

1. satellite and radar images
2. flood maps / floodplain hydraulicmodels
3. river gauging stations
4. all of the above

30. Which of the following is true? Flood warnings:

1. should not be released until the information is certain
2. should indicate what the threat is, what action should be taken, by whom and when
3. are best if they come from a single source
4. all of the above