River Systems

chapter 15 Holt

• 1. The continuous movement of water from the atmosphere to the land and oceans and back to the atmosphere is called the water cycle.

• 2. A region’s water budget is affected by temperature, vegetation, wind, and the amount and duration of rainfall.

• 3. The availability of fresh water can be enhanced through conservation efforts.

• Water cycle, 375• Evapotranspiration, 376• Condensation, 376• Precipitation, 376• Desalination, 378

• 4. A river system is made of a main stream and feeder streams, called tributaries.

• 5. A watershed is the area of land that is drained by a river system.

• 6. The erosive ability of a river is affected by stream load, stream discharge, and stream gradient.

• 7. A bend in a low-gradient stream or river is called a meander.

• 8. A river that is composed of multiple channels that divide and rejoin around sediment bars is called a braided stream.

• Tributary, 379• watershed, 379• stream load, 380• discharge, 380• Gradient, 380• meander, 381• braided stream, 382

• 9. Where a stream slows significantly, it can deposit its stream load to form deltas and alluvial fans.

• 10. In floodplains, flooding commonly brings in new, rich soil for farming but can cause property damage.

• 11. Floods can be controlled through forest and soil conservation and by building structures such as levees and dams.

• delta, 383

• Alluvial fan, 383

• Floodplain, 384