Nat Geo-Understanding Rivers

According to the article, which of the following is a common source, or headwater, of a river?

• Delta

• Melting Glacier

• Tributary

• Floodplain

The article defines a river, all its tributaries, and the associated groundwater resources as a...

• water table
• delta

• drainage basin or watershed

• meander

The article describes the Grand Canyon being carved by the Colorado River. What two processes are primarily responsible for this shaping of the landscape?

• Volcanic activity and uplift
• Erosion and weathering
• Glacial movement and deposition
• Sedimentation and compaction

When a river flows onto lower land and its slope flattens, the article states it begins to form looping bends called

• rapids

• deltas

• meanders
• floodplains

What term does the article use for the rocks, sand, and other solid material deposited by a river?

• Bedrock

• Debris

• Pollution

• Alluvium (or sediment)

According to the reading, a delta forms at the mouth of a river when

• deposited sediment partially blocks the river's flow to the sea

• human-made dams block the water

• the river carves a V-shaped valley

• the rivers slope increases

he article lists several environmental challenges facing rivers. What is described as a negative environmental effect of dams?

• They generate renewable energy without greenhouse gases.

• They prevent flooding and curb erosion

• They provide water for irrigation

• They change the river's flow and temperature, harming fish.

The article discusses pollution in the Mississippi River, stating that runoff creates a 'dead zone' in the Gulf of Mexico. This 'dead zone' is an area where

• water is diverted for agriculture.

• there is not enough oxygen to support life.

• sediment forms a new delta

• hydroelectric power is generated

How does the article connect rivers to the larger water cycle?

• Rivers trap saltwater, preventing it from evaporating

• Rivers are formed by ocean currents

• Rivers carry water from land to the ocean, where evaporation and cloud formation occur

• Rivers are the primary source of evaporation

The article compares the Nile and the Amazon rivers. While the Nile is slightly longer, the Amazon is recognized as the largest river by what measure?

• Number of tributaries

• Volume of water

• Age

• Political importance