Floods are also responsible for moving large amounts of sediments about within streams.
These sediments provide habitats for animals, and the periodic movement of sediment is
crucial to the lives of several types of organisms. Many plants and fish along the Colorado
River, for example, depend on seasonal flooding to rearrange sand bars.
Lesson Summary
- One way water returns to the oceans is through rivers and streams.
- Streams begin in higher elevations, with many tributaries joining together as it flows
to lower elevations. - A mature river will develop a floodplain and may eventually form a delta where the
river meets the ocean. - Water temporarily resides in ponds and lakes, which are mostly freshwater.
- Scientists study lakes, wetlands and estuaries because they are biologically important
areas. - Flooding is part of the natural cycle of all rivers, which enriches floodplains with
important nutrients. - Flooding produces difficulties for humans living on or near the floodplain and in coastal
areas, particularly when levees break.
Review Questions
- Where do streams originate?
- Compare and contrast streams and rivers.
- What is an advantage and disadvantage of living in floodplains?
- Which of the 10 longest rivers has the greatest rate of flow?
- Compare and contrast ponds and lakes.
- What are 3 main types of wetlands?
- Considerananimalcommoninswampsandananimalcommoninrivers. Whatnatural
adaptations do they each have to their habitat? - Deserts are places that get little rain. Why are they in danger of flash floods at times?
Vocabulary
aphotic zone The region in a freshwater body where no sunlight can reach. Also called
the deepwater zone or the profundal zone.
brackish Water that is a mixture of freshwater and saltwater.
confluence The point where two streams join together.