Question

1) Why are debris flows more dangerous compared to flash floods?

a. They involve water runoff that travels in a valley, canyon, or stream channel

b. They can happen at any time, day or night

c. They happen within minutes of intense rainfall or snow melt

d. They carry massive amounts of sediment and thus have greater depths

e. They recur again and again throughout the rainy season

2) Given the deadly debris flow hazard, the growing population, and the size of land areas impacted by fires annually, how is the U.S. Geological Survey currently working to address this hazard?

a. Construction of dams to catch water runoff

b. Construction of sediment retention basins at the bottom of drainage basins

c. Construction of culverts to carry flows away

d. Construction of bridges to prevent the community from crossing channels with vehicles

e. Developing an early warning system to inform neighborhoods of approaching storms that are high risk

f. All of these

3) Which monitoring technique or information source will provide ample notice of a pending debris flow?

a. Watching areas upstream with motion-triggered cameras

b. Reading recently logged 911 calls

c. Monitor real-time changes in stream discharge via the USGS website

d. Monitoring ground motions using seismometers

e. National Weather Service "watch" alerts on the threat of debris flows and flash floods

f. Flash flood "warnings" released by the National Weather Service

4) What is the most serious issue with post-fire debris flow early warning systems?

a. The time period between the arrival of a storm and the initiation of a debris flow is typically only minutes

b. Local officials do not publicize the risk

c. NOAA is not able to produce warning products in a timely fashion

d. People choose to not evacuate in advance and then miss the short-notice tell-tale signs

e. NOAA cannot avoid false alarms

5) Those who choose to stay in their homes are most likely to survive a debris flow by taking the following action:

a. Seek higher ground on foot

b. Move their belongings to another area

c. Use a vehicle to seek higher ground

d. Move upstairs or to the roof of the home to avoid the flow

5) How could climate change contribute to an increased debris flow hazard?

a. Warmer ocean temperatures lead to more evaporation and higher intensity storms

b. Warmer air can hold more water vapor and bring higher rainfall intensities

c. Warming that causes droughts on land that can increase the fire hazard

d. All of these

Answer 1

1. d. They carry massive amounts of sediment and thus have greater depths

2. f. All of these

3. e. National Weather Service "watch" alerts on the threat of debris flows and flash floods

4.a. The time period between the arrival of a storm and the initiation of a debris flow is typically only minutes

5. d. Move upstairs or to the roof of the home to avoid the flow

6. d. All of these

Step-by-step explanation:

Debris flow is the mass movement of large sediment, boulders from a slope . Usually it is a slow movement of this sediment but rain and thunderstorm can rapidly increases the speed of movement.

Construction of dams assist to channel water rightly which is an agent of debris flow . Construction of sediment retention basin slows down sediment disintegration and movement. Construction of culverts reduces the flows devastation. Developing an early warning system also address the hazard of debris flows.

Moving upstairs or to the roof top of a house is likely to save a victim of debris flow in his or her home.

Warmer oceans temperatures lead to more evaporation and high intensity storm. Warmer air holds more water and therefore causes more rain. Drought indirectly causes fire hazard.