How hazards and resources shaped where people live
Grade 9 Science Worksheet - Building Confidence
Circle the best answer.
Read this first
Use this
A world map marking the Ring of Fire and the Nile and Mississippi floodplains.
Why have river floodplains drawn farms and towns, by Ari's reading (USGS)?
- Floods stop once towns are built on the plain
- Floodplain soil is thin and rocky, so it is easy to dig
- Rivers carry the soil away, leaving flat bare rock
- Flood sediment leaves mineral-rich soil that makes excellent farmland
Besides fertile soil, what else do river valleys offer people, by Bo's reading (USGS)?
- Water, and routes for boats, roads and railroads
- Cooler weather with no rain or floods in any season
- Shelter from each kind of natural hazard
- Deep beds of fresh volcanic soil
Why do people farm the slopes of some volcanoes, by Kira's reading (USGS)?
- Volcanoes stop erupting once farms are planted
- Volcanic slopes get no rain, so crops stay dry
- Volcanic rock weathers into some of Earth's most fertile soils
- Fresh lava rock is soft enough to plow
Where do most earthquakes and volcanic eruptions happen, by Jun's reading (USGS)?
- At random spots anywhere on Earth
- Along plate boundaries, like the Ring of Fire
- Mostly near the North and South Poles
- Mostly in the middle of plates, far from their edges
Why do millions of people feel earthquakes in places like California, by Milo's reading (USGS)?
- Earthquakes follow people to crowded places
- Cities make the plates move faster
- Many big cities sit near active faults, like the San Andreas
- California is sliding off into the sea
Model sites (model data)
Site Soil Fresh water Transport Main hazard A: river floodplain rich river soil river river and rail floods B: volcano slope rich volcanic soil springs one road eruptions C: coast sandy soil wells port storm surge D: dry plateau thin soil little few roads drought Using the model table, what is site B's main hazard, by Pia's reading?
- Eruptions
- Drought
- Storm surge
- Floods
Using the model table, which site has the least fresh water, by Ren's reading?
- Site A, the river floodplain
- Site D, the dry plateau
- Site C, the coast
- Site B, the volcano slope
What does a 100-year flood mean, by Tala's reading (USGS)?
- A flood that can't happen two years in a row
- A flood with a 1% chance of happening in any year
- A flood that covers 100 miles of river
- A flood that comes once each 100 years, on schedule
Last year a river had a 100-year flood. What is the chance of one this year, by Zee's reading (USGS)?
Use the picture in question 8.
- 0%, since one just happened
- 100%, since floods repeat each year
- Still 1%
- 50%, since it is like a coin toss
USGS: a 100-year flood has a 1% yearly chance. By the same rule, what yearly chance does a 500-year flood have, by Esme's math?
Use the picture in question 8.
- 5%
- 0.2%
- 0.5%
- 2%