Floods Multiple Choice Questions and Answers

31. A flood can vary in:

1. size
2. speed of water flow
3. duration
4. all of the above

32. Channelization of streams is designed to reduce flooding by

1. speeding the passage of floodwaters
2. reducing bank erosion
3. slowing down river velocity so as to reduce damage
4. increase the meandering of streams

33. A stream with too much bed load will usually have what type of channel pattern?

1. straight
2. meandering
3. braided
4. dendritic

34. Which of the following measurements is not needed to estimate stream discharge?

1. stream velocity
2. width of stream
3. bed load of stream
4. depth of stream

35. Flood risk refers to:

1. the chance of a flood occurring
2. the number of people and properties exposed to floodwaters if a flood occurs
3. the vulnerability of people and properties that are exposed to floodwaters
4. all of the above.

36. The size of a flood is measured by:

1. the rate of flow of water in a waterway or river
2. the level of water in a waterway or river
3. a river gauging station
4. all of the above.

37. Which of the following is associated with a La Niña event?

1. the Southern Oscillation Index (SOI) is strongly negative
2. the ocean surface off the coast of South America is warmer than usual
3. there is an increased chance of above average rainfall in easte rn Australia
4. all of the above.

38. When a rivers water level reaches 10 metres, this means that:

1. the water level is 10 metres above an arbitrary zero level
2. the water level is 10 metres above mean sea level
3. the water level is 10 metres above mean sea level or an arbitrary ‘zero level
4. it will flood.

39. In the future, which of the following is unlikely?

1. there will be an increased chance of flash flooding and coastal inundation
2. flood risk will increase due to population growth and urbanisation
3. improvements in flood forecasting and warning technologies will reduce the impacts of floods
4. we will be able to eliminate the risk of flooding.

40. Dikes and dams are lined up along the coast of the Netherlands

1. to generate electricity for its population
2. to change the course of rivers that flow into the North Sea
3. to keep storms away from the country
4. to keep ocean w ater out of the lower lying land