Flowing Water Flashcards
A ___ is a body of water flowing in a natural channel, such as a river, creek, or brook.
Stream
___ ___ are fed by both runoff and groundwater and flow year round.
Permanent streams
___ ___ are fed only by runoff and flow only during wet times of the year or after storm events.
Ephemeral streams
Streams flow from their___ to their ___, where they generally empty into a larger body of water.
Headwaters; Mouths
Small streams that flow into larger streams are called ___.
Tributaries
Solar energy drives ___ from the oceans, adding water vapor to the atmosphere. ___ over land produces ___, which flows by gravity to return water to the oceans.
Evaporation; Precipitation; Runoff
The land area from which water flows into a particular stream system.
Drainage basins
Adjacent drainage basins are separated by ___.
Drainage divides
What describes a system of streams and tributaries that resembles the branches of a tree. The most common drainage pattern?
Dendritic pattern
What describes a system of streams and tributaries that radiate from a central point, like the spokes of a wheel. Often seen on conical mountains, such as volcanoes?
Radial pattern
What describes a system of streams and tributaries that follow relatively straight courses, with bends at right angles. Develops on landscapes where the bedrock has pronounced joints or fractures that control the drainage?
Rectangular pattern
What describes a system of streams and tributaries that flow in parallel valleys between ridges, with occasional water gaps through the ridges?
Trellis pattern
A stream’s discharge over time is depicted in a graph called a
___.
Hydrograph
The volume of water flowing through a stream channel, generally in measured cubic feet per second or cubic meters per second.
Discharge
How does size of a watershed affect discharge?
Larger watersheds yield higher discharges
How does precipitation affect discharge?
High precipitation yields higher discharges
How does percent runoff affect discharge?
High percent runoff yields higher discharges
Rivers and streams are not only conveyors of water, they also move large amounts of sediment which are called ___.
Sediment loads
The sediment load of a stream consists of:
Dissolved load; Suspended load; Bedload
Dissolved load:
Dissolved ions
Fine sediment particles (clay, silt, sand) carried in the water above the stream bed.
Suspended load
Coarse sediment (sand, gravel, boulders) transported by the stream by rolling, sliding, or bouncing along the stream bed.
Bedload
The largest size sediment particle the current of a stream is able to transport.
Competence
Competence is determined by ___ and ___.
Flow velocity; Channel slope
A graph showing a stream’s gradient along its course from its headwaters to mouth.
Longitudinal Profile
What refers to erosion of a stream valley that extends the valley uphill?
Headward erosion
The situation in which headward erosion of one stream cuts into the channel of another stream, diverting and “capturing” its flow.
Stream Piracy
A stream’s ___ is the level below which it cannot erode, usually determined by the level of the body of water into which it flows
Base level
The ___ of all rivers and streams is sea level, but for streams flowing into lakes the lakes are ___.
Global base level; Local base levels
The situation in which a stream flowing relatively close to its base level begins to erode its channel more deeply due to a drop in base level or tectonic uplift of the terrain.
Rejuvenation
