1 / 15

Thinking Questions

Thinking Questions. Why is Freshwater so Rare? What is a River? What makes up a river? What creates rivers? What is a flash flood? What is needed to have a flash flood occur? Why is our area of NC prone to Flash floods? Why are mountains also prone to Flash Flooding?. Freshwater Systems.

althea
Télécharger la présentation

Thinking Questions

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Thinking Questions • Why is Freshwater so Rare? • What is a River? • What makes up a river? • What creates rivers? • What is a flash flood? • What is needed to have a flash flood occur? • Why is our area of NC prone to Flash floods? • Why are mountains also prone to Flash Flooding?

  2. Freshwater Systems You will be able to: Explain how Rivers shape the land Identify conditions which cause flooding Identify the different zones and characteristics of River Systems

  3. Water Cycle • Fresh Water comes from the Water Cycle • Water Cycle Diagram: here

  4. Where is the Water? • 71% of Earth is covered by water • 29% Terrestrial Surface • 3% of water is Fresh • 97% of all water is salt water

  5. Where’s the FRESHWATER?

  6. Where’s the Freshwater? • Water in Ice caps completely frozen all year round • Making ground water the largest supplier of the world’s FRESH WATER!

  7. The 1%: How Rivers Form • All Rivers form from Run-off • Run-off is water that is not absorbed by the ground. • Produced from precipitation and seasonal melting of snow and glaciers • Run-off rates may change at different locations within a River System

  8. What affects Run-Off Rate?(3 things) • Soil Type – Major factor in determining run-off rates. Different soil types have different abilities to containing water. • Precipitation/Melting amounts- Amount of water that is able to fall upon ground • Topography of Land- Hills produce more run-off than flat areas because gravity pulls water down the sides of the hill and not into the soil

  9. Soil Types • Soils have different Run-off traits because of 2 primary factors • Porosity- amount of empty spaces between soil particles • Permeability- how well empty spaces are aligned. • If both values are low, high run off rates will occur • 3 Basic soil Types in NC, gravel based, clay based, or sand based

  10. Soil Types (Con’t) • Different Soil types traits are best described using 2 terms; • Aquifer- Material that allows water to travel through it easily (high porosity, high permeability) • Aquitard- material that DOES NOT allow water to travel through it easily. (low porosity, low permeability)

  11. What River Systems Share • 1st Zone- Headwaters • Small Tributaries/streams formed along sides of mountains • Streams are narrow but deep in places • High erosion occurs here • Animals small in size and streamlined

  12. What River Systems Share • 2nd Zone- Downriver • Tributaries merge and form larger water system; Current here fast and strong ”White Water rafting” • Rivers wider, straighter • high erosion; little deposition • Animals larger and still streamlined

  13. What River Systems Share • Flood Plain- 3rd zone • Rivers begin to twist and turn, • Current slows dramatically • River is at its widest but also fairly shallow • Erosion rates equal Deposition rates; Bends in rivers called Meanders • Organisms are largest here; not as streamlined.

  14. What River Systems Share • 4th Zone- Estuary/Mouth/Delta • Where River empties into Sea • Current here very slow • No Erosion, High Deposition rates • Organisms actually get smaller in size as you approach ocean,

  15. What River Systems Share • Watershed- Entire area of Land that gives run-off to a River System • Divide- Geographical region which separates River Systems; Usually a mountain range

More Related