GEOTOURS: Fluvial Landscapes

The images are satellite images from

Google Earth. Some are top-down

photographs. Others are taken at sides or

from oblique low angles. The pictures

represent some of the best examples of

fluvial landscapes on Earth. The name of

the geographic location is provided so that

you can research and learn more about each

landscape. Use your notes to compare the

images with the diagrams in your notes.

Enjoy

Feature: WATER GAP

The picture is of the Cumberland Narrows, Maryland. The stream, Wills Creek, downcut

through the mountain creating the water gap. The stream is older than the mountain. As the

mountain was forming and being pushed up under the stream, the stream eroded downward

through the mountain. In the picture, the stream is between the railroad and the road.

Feature: WATER GAP

The picture is of Rocky Gap, Virginia. The stream, Wolf Creek, eroded through Bland

Mountain in southwest Virginia. As the mountain was forming and being pushed up under the

stream, the stream eroded downward through the mountain. In the picture, the stream is between

the northbound and southbound lanes of Interstate 77.

Feature: FLOODPLAIN

The floodplain lies in a wide valley in southwest Virginia. Over millions of years, the

stream, Wolf Creek, has widened the valley to make a nearly level floodplain. When Wolf

Creek floods, the water flows over Wolf Creek’s banks and fills the floodplain.

Feature: FLOODPLAIN

The picture is of Newcastle, England and the Tyne River. The Tyne River has a very wide

floodplain in between large bluffs (linear rounded hills that enclose the river in a valley). There

is extensive farmland covering the nearly level floodplain. Levees have been built along the

river to control flooding.

Feature: MEANDERING RIVER AND ASSOCIATED FEATURES

The Mississippi River is a meandering river below St. Louis Missouri. This aerial photograph

is the Mississippi River in Louisiana. Meanders are very large curves of the river channel. Lake

Mary is an oxbow lake, a curved or crescent-shape lake next to a meandering river. Lake Mary

used to be part of the river, but got separated from the river when its neck got eroded through.

The meander cutoff is located at Artonish. The meander cutoff is the straighter river channel

that cut through the meander neck, separating the river from the oxbow lake. The curved strips

of land near Ashland are called meander scars. Meander scars swampy sediment filled remains

of older oxbow lakes—they look like wood-covered curves. The floodplain is very large. Most

of the floodplain is lower in elevation than the river. That is called the backswamp.

Feature: MEANDERING RIVER AND ASOCIATED FEATURES

This is the Arkansas River in Arkansas. The features of the meandering river system are

labeled.

Oxbow

lake

Oxbow

lake

Cutoff

Oxbow

lake

Oxbow

lake

Scars Scars

Backswamp

Backswamp

Feature: MEANDERING RIVER AND ASSOCIATED FEATURES

The Mississippi River is a meandering river below St. Louis Missouri. This aerial photograph

is the Mississippi River in Louisiana. Meanders are very large curves of the river channel. Lake

Bruin and the lake near Newellton are oxbow lakes, curved or crescent-shape lakes next to a

meandering river. Lake Bruin used to be part of the river, but got separated from the river when

its neck got eroded through. The meander cutoff is located to the right of St. Joseph. The

meander cutoff is the straighter river channel that cut through the meander neck, separating the

river from the oxbow lake. The curved strips of land near the word Mississippi in the middle of

the photograph, Davis Island, and Notmac are called meander scars. Meander scars swampy

sediment filled remains of older oxbow lakes—they look like wood-covered curves.

FEATURE: DELTA

This is a photograph of the Volga River delta flowing into the Caspian Sea. Deltas are

depositional landforms. They are created when fast moving rivers flow into calm, deep large

bodies of water like oceans and very large lakes. The sediments carried by the river settle or are

deposited next to the river’s mouth. Over time, the sediments accumulate and make a great

delta—extensive marshy land at the mouth of the river. Distributaries are small branching

channels that carry the river water through the delta to the open ocean or lake.

FEATURE: DELTA

This is a photograph of the Stillagushmish delta flowing into the Puget Sound in Washington.

Deltas are depositional landforms. They are created when fast moving rivers flow into calm,

deep large bodies of water like oceans and very large lakes. The sediments carried by the river

settle or are deposited next to the river’s mouth. Over time, the sediments accumulate and make

a great delta—extensive marshy land at the mouth of the river. Distributaries are small

branching channels that carry the river water through the delta to the open ocean or lake.

Feature: GORGE OR CANYON

A gorge or canyon is a river valley in which the sides are very steep or vertical. There is no

floodplain. The river cuts downward through a plateau. The rivers or streams flow very fast.

This is the Snake River in Idaho and Oregon. The Snake River is actively downcutting into the

mountains and the canyon will become deeper and wider with time.

FEATURE: GORGE or CANYON

This is a photograph of the Cheat River Gorge in West virginia. A gorge or canyon is a river

valley in which the sides are very steep or vertical. There is no floodplain. The river cuts

downward through a plateau. The rivers or streams flow very fast. A plateau is a high-

elevation flat geographic area. The Cheat River is in a humid climate with a lot of rain. The

sides are steeply sloping.

FEATURE: GORGE or CANYON

This is a photograph of the Colorado River canyon (Grand Canyon) in Arizona. A gorge or

canyon is a river valley in which the sides are very steep or vertical. There is no floodplain.

The river cuts downward through a plateau. The rivers or streams flow very fast. A plateau is

a high-elevation flat geographic area. The Grand Canyon is in a desert (arid environment).

There is very little rain. As a result, the sides of the canyon tend to be vertical and not sloping.

Feature: BRAIDED RIVER CHANNEL

A braided river channel is a wide and flat river valley that has a river or stream clogged with

gravel and sediments. As a result, the river water divides and recombines as it weaves around the

mounds of gravel and seidments. The small pointy islands in the braided river channel are called

gravel bars or channel bars. The picture shows an aerial view of the North Platte River in western

Nebraska.

Feature: BRAIDED RIVER CHANNEL

A braided river channel is a wide and flat river valley that has a river or stream clogged with

gravel and sediments. As a result, the river water divides and recombines as it weaves around the

mounds of gravel and seidments. The small pointy islands in the braided river channel are called

gravel bars or channel bars. The picture shows an aerial view of the Rakaia River near Cantebury,

New Zealand.

Feature: V-SHAPE VALLEY

V-shape valleys are river or stream valleys that have sloping sides and narrow floodplains V-

shape valleys form when the river in the valley erodes side-to-side and downward at the same

time. This makes the valleys wider than canyons and the sides of the valleys at more gradual

slopes. The picture shows a V-shape valley in Erwin, Tennessee. The valley was carved by

the Nollachucky River.

Feature: V-SHAPE VALLEY

V-shape valleys are river or stream valleys that have sloping sides and narrow floodplains V-

shape valleys form when the river in the valley erodes side-to-side and downward at the same

time. This makes the valleys wider than canyons and the sides of the valleys at more gradual

slopes. The picture shows a V-shape valley in Ingleby, Pennsylvania. The valley was carved

by the Juniata River.

Feature: MISFIT STREAM

A misfit stream valley is usually a very large, very wide valley in mountainous regions that has

a single stream. That stream is too small to have eroded the valley. The stream is “misplaced”,

it came after the valley was formed. Misfit streams tend to be braided streams or meandering

rivers. Most misfit streams are in U-shape valleys carved by alpine glaciers. The photograph is

of the Bear River near Corinne, Utah.

Feature: MISFIT STREAM

A misfit stream valley is usually a very large, very wide valley in mountainous regions that has

a single stream. That stream is too small to have eroded the valley. The stream is “misplaced”,

it came after the valley was formed. Lingmoor Fell in England is a misfit stream that lies in U-

shape valley that was carved by an alpine glacier.

FEATURE: RADIAL REGIONAL DRAINAGE PATTERN

This is a photograph of the volcanic island Tristan de Cuhna in the South Atlantic Ocean.

Radial regional drainage pattern is where all of the rivers and streams flow downward and

outward from a central isolated mountain summit. Rivers and streams start at the volcano’s

summit, and flow down in all directions away from the summit. The top photograph shows the

top-down view. The bottom photograph shows the oblique angle view.

FEATURE: DENDRITIC REGIONAL DRAINAGE PATTERN

This is a photograph of the Wadi Al Masila River system in Yemen on the Arabian Penninsula.

Dendritic regional drainage pattern is where the system of streams and rivers connect in a

pattern like roots on a tree or branches on a tree. The bedrock is horizontal and in layers. The

river is ephemeral (only filled with water after rainfall) and is dry most of the year. The desert

environment shows the channels.

FEATURE: PARALLEL REGIONAL DRAINAGE PATTERN

This is a photograph of the Caucasus Mountains in Azerbaijan near the Caspian Sea. Parallel

regional drainage pattern is where the system of streams and rivers flow down steeply tilted

rock layers in the same direction. The channels are parallel to each other with moutain ridges

separating the channels. The top photograph is a aerial top-down view. The bottom photograph

is an oblique angle view.

FEATURE: TRELLIS REGIONAL DRAINAGE PATTERN

This is a photograph of the middle Ridge and Valley near Moorefield, West Virginia. Trellis

regional drainage pattern develops in a ridge and valley landscape where ridges (mountains)

and valleys are linear and parallel to each other. Small streams flow down either side of the

mountain ridges into the valleys, where they intersect with the much larger rivers at right

angles. Trellis means they look like posts on a fence intersecting at right angles.

FEATURE: RECTANGULAR REGIONAL DRAINAGE PATTERN

This is a photograph of bare Canadian Shield in Labrador, Canada. Rectangular regional

drainage pattern develops on very hard crystalline rock (like granite or metamorphic rock) that

is jointed and cracked in patterns at right angles. Waterways (streams and rivers) and narrow

lakes fill the joints.

FEATURE: DERANGED REGIONAL DRAINAGE PATTERN

This is a photograph of Kenora, Ontario Canada, near the Attawapiskat River. A deranged

regional drainage pattern is on a young landscape covered by glacier deposits. This flat

landscape was covered by continental glaciers 10,000 years ago. After the ice melted, the

sediments left behind by the melted glaciers cover the land. Rivers and streams have no direction,

they flow slowly in and out of lakes, marshes, and bogs.

FEATURE: ANNULAR REGIONAL DRAINAGE PATTERN

This is a photograph of Pavillion, Wyoming. This is a dome structure with annular regional

drainage. The streams flow in concentric rings around the dome, connected to each other through

breeches in the rock layers. The upper photograph is a top-down view of the dome. The lower

photograph is an oblique angle view.

FEATURE: CENTRIPETAL REGIONAL DRAINAGE PATTERN

This is a photograph of a desert basin in Central Nevada. Centripetal regional drainage

pattern is when rivers and streams flow into a basin or lowland, and teminates. This photograph

shows a series of dry washes (dry rivers) that drain into a salt-clogged lake in the lowest elevation

of the basin. All of the streams from all direction flow into the lake, the end of the water’s journey.