Chapter 16 - Running Water

Front 1

What is the circulation of Earth's water supply between the hydrosphere, atmosphere, geosphere, and biosphere called?

Back 1

The hydrologic cycle

Front 2

How does urbanization (e.g., paving) affect runoff and infiltration in a small, previously forested, drainage basin?

Back 2

Runoff increases and infiltration decreases.

Front 3

Which of the following must result in a lower base level for river and streams?

Back 3

Sea level drops; land rises.

Front 4

Many large rivers in the Colorado Plateau meander in deep, narrow canyons and have no floodplains. How could this happen?

Back 4

Streams flowing in meanders cut down as the plateau rose.

Front 5

Which river has the largest discharge of any in the world?

Back 5

Amazon

Front 6

What will happen when a dam and reservoir are constructed on a graded river?

Back 6

Deposition upstream from the dam; channel downcutting below

Front 7

Rivers and streams are persistent features on Earth's surface. Of the list below, which river, in its present state, is probably the oldest?

Back 7

Amazon

Front 8

What type of flood? Seasonal precipitation or spring snowmelt over many watersheds and drainage basins; Mississippi River system annually

Back 8

Regional Floods

Front 9

What type of flood? Local rainstorms, sometimes after a forest fire, deluging streams, creating a wall of water that roars down a canyon, and taking everything in its path; Big Thompson Canyon flood in Colorado, 1976

Back 9

Flash flood

Front 10

What type of flood? Form "bottlenecks" in the channel; occur repeatedly in the Red River in North Dakota

Back 10

Ice-jam floods

Front 11

What type of flood? Failure of human structures function; Johnstown Flood in Pennsylvania in 1889

Back 11

Dam-failure floods

Front 12

What is a braided channel, and what is happening there?

Back 12

Wide and shallow stream, usually at the ends of glaciers; is choked with sediment, where there is not much "downhill"

Front 13

What is the difference between a bar and a point bar?

Back 13

A bar is a small-scale channel deposit, sometimes elongated, in the middle of a stream; a point bar is a deposit of sediment on the inside of a meander. Both are good places to find gold nuggets.

Front 14

Which best describes the difference between a delta and an alluvial fan?

Back 14

A stream deposits sediments at its mouth in water in a delta; a stream deposits sediments along steep mountain slopes in an alluvial fan.

Front 15

Which of the following best describes a water gap?

Back 15

A steep-walled notch cut through a tectonic structure, usually a ridge of tilted rock

Front 16

Why has Niagara Falls lasted so long and cut its channel back 7 miles (11 kilometers)?

Back 16

The Lockport Dolostone is a resistant rock unit that covers a wide zone between Lake Erie and Lake Ontario, and the Niagara River has to erode the weak layers underneath before it can retreat upstream.

Front 17

Which one of the following statements correctly describes how stream terraces can form?

Back 17

A temporary base level is eliminated; the stream cuts down upstream from the old temporary base level, and the former floodplain is left well above the present elevation of the stream.

Front 18

Which of the following best describes the development of distributaries at the mouths of major rivers such as the Mississippi River?

Back 18

The main channel divides into several smaller channels, carrying water in varying paths to base level.