Drainage Basins and River Systems Lecture

Flashcards covering drainage basins, river morphology, delta evolution, and erosion processes such as headward erosion and avulsion.

Drainage basin

A region where all surface water flows into a specific stream, such as those identified for stream A and stream B.

Sub watersheds

Smaller drainage units within a larger basin that are often organized around tributaries.

Tributaries

Streams that flow into a larger stream or river.

Drainage divide

The boundary or high ground that separates one drainage basin from another.

Continental divide

A major drainage divide that separates river systems which flow into different oceans, such as the divide between the Pacific Ocean and the Gulf of Mexico.

Mouth

The point where a river or stream flows into a larger body of water, such as an ocean, lake, or another river.

Mountain stream

A smaller, steep, and rocky stream typically found in high-elevation areas like Denali National Park.

Lowland stream

A river that, as it approaches the mouth, gradually becomes larger, calmer, and less steep.

Longitudinal profile

A cross-sectional view of a river's elevation from its source to its mouth relative to the distance from its mouth.

Base level

The lowest elevation to which a stream can erode its channel, defined as the level which the water is flowing down to.

Archetypal model (Rivers)

A standard river model, exemplified by the Amazon, that transitions from steep mountain streams to large, calm lowland rivers.

Avulsion

The process by which delta distributaries switch their course to find the shortest route down to the base level.

Sediment plumes

Visible clouds of sediment discharged into a body of water, often highlighting the location of major deltas, as seen in images from May 6, 2013.

Headward erosion

The process where a stream or waterfall erodes the rocks it flows over, causing the position of the falls to migrate upstream.

St. Anthony Falls

A waterfall in the Mississippi Gorge in Minneapolis that serves as an example of headward erosion where a dam was eventually built.

Niagara Falls historical retreat rate

The speed at which the falls migrated upstream before human intervention, measured at $1\,m/yr$.

Niagara Falls current retreat rate

The slowed speed of upstream migration of the falls due to human intervention, measured at $0.5\,m/yr$.

Lockport Dolostone

The specific rock layer shown in the model of Niagara Falls that sits atop the fall's structure.

Niagara Escarpment

The steep cliff or slope in the Niagara Gorge over which the river flows.

Wave train

A series of waves observed in the Congo River, specifically noted near Inga and the Kinshasa region.

Sediment size (Congo River images)

Grains that are large enough to be visible from satellite images, indicated by a yellow bar $40$ feet ($13.03\,m$ ground length) across.

Atchafalaya River

A river channel associated with the Mississippi River system that is part of the landscape evolution of deltas.

Mississippi River basin limit

The geographical boundary defining the total area drained by the Mississippi River and its tributaries.

Source

The beginning or upper reaches of a stream system where water and sediment transport originates.

Sink

The final destination area, such as a delta or ocean, where a stream system transports water and sediment.

Local base level

A base level that is not the global sea level, such as a lake or a dammed reservoir.

"Castles Made of Sand"

An analogy used by McConnell to represent houses built near coasts that are vulnerable to rising sea levels.