(See related pages)
Below you will find key words and concepts that you should remember from this chapter.
|
|
|
| abrasion | The grinding away of rock by friction and impact during transportation. (See page(s) 401) |
| |
| |
| |
| alluvial fan | Large fan-shaped pile of sediment that usually forms where a stream’s velocity decreases as it emerges from a narrow canyon onto a flat plain at the foot of a mountain range. (See page(s) 412) |
| |
| |
| |
| bar | A ridge of sediment, usually sand or gravel, that has been deposited in the middle or along the banks of a stream by a decrease in stream velocity. (See page(s) 403) |
| |
| |
| |
| base level | A theoretical downward limit for stream erosion of Earth’s surface. (See page(s) 419) |
| |
| |
| |
| bed load | Heavy or large sediment particles in a stream that travel near or on the stream bed. (See page(s) 402) |
| |
| |
| |
| braided stream | A stream that flows in a network of many interconnected rivulets around numerous bars. (See page(s) 406) |
| |
| |
| |
| delta | A body of sediment deposited at the mouth of a river when the river velocity decreases as it flows into a standing body of water. (See page(s) 409) |
| |
| |
| |
| dendritic pattern | Drainage pattern of a river and its tributaries, which resembles the branches of a tree or veins in a leaf. (See page(s) 397) |
| |
| |
| |
| discharge | In a stream, the volume of water that flows past a given point in a unit of time. (See page(s) 400) |
| |
| |
| |
| dissolved load | The portion of the total sediment load in a stream that is carried in solution. (See page(s) 402) |
| |
| |
| |
| distributary | Small shifting river channel that carries water away from the main river channel and distributes it over a delta’s surface. (See page(s) 409) |
| |
| |
| |
| divide | Line dividing one drainage basin from another. (See page(s) 396) |
| |
| |
| |
| downcutting | A valley-deepening process caused by erosion of a stream bed. (See page(s) 419) |
| |
| |
| |
| drainage basin | Total area drained by a stream and its tributaries. (See page(s) 396) |
| |
| |
| |
| drainage pattern | The arrangement in map view of a river and its tributaries. (See page(s) 397) |
| |
| |
| |
| flood plain | A broad strip of land built up by sedimentation on either side of a stream channel. (See page(s) 409) |
| |
| |
| |
| graded stream | A single bed with coarse grains at the bottom of the bed and progressively finer grains toward the top of the bed. (See page(s) 419) |
| |
| |
| |
| headward erosion | The lengthening of a valley in an uphill direction above its original source by gullying, mass wasting, and sheet erosion. (See page(s) 422) |
| |
| |
| |
| hydraulic action | The ability of water to pick up and move rock and sediment. (See page(s) 401) |
| |
| |
| |
| hydrologic cycle | The movement of water and water vapor from the sea to the atmosphere, to the land, and back to the sea and atmosphere again. (See page(s) 395) |
| |
| |
| |
| incised meander | A meander that retains its sinuous curves as it cuts vertically downward below the level at which it originally formed. (See page(s) 424) |
| |
| |
| |
| lateral erosion | Erosion and undercutting of stream banks caused by a stream swinging from side to side across its valley floor. (See page(s) 423) |
| |
| |
| |
| meander | A pronounced sinuous curve along a stream’s course. (See page(s) 407) |
| |
| |
| |
| meander cutoff | A new, shorter channel across the narrow neck of a meander. (See page(s) 407) |
| |
| |
| |
| natural levee | Low ridges of flood-deposited sediment formed on either side of a stream channel, which thin away from the channel. (See page(s) 409) |
| |
| |
| |
| oxbow lake | A crescent-shaped lake occupying the abandoned channel of a stream meander that is isolated from the present channel by a meander cutoff and sedimentation. (See page(s) 409) |
| |
| |
| |
| point bar | A stream bar (see definition) deposited on the inside of a curve in the stream, where the water velocity is low. (See page(s) 407) |
| |
| |
| |
| pothole | Depression eroded into the hard rock of a stream bed by the abrasive action of the stream’s sediment load. (See page(s) 401) |
| |
| |
| |
| radial pattern | A drainage pattern in which streams diverge outward like spokes of a wheel. (See page(s) 397) |
| |
| |
| |
| rectangular pattern | A drainage pattern in which tributaries of a river change direction and join one another at right angles. (See page(s) 397) |
| |
| |
| |
| saltation | A mode of transport that carries sediment downcurrent in a series of short leaps or bounces. (See page(s) 402) |
| |
| |
| |
| sheetwash | Water flowing down a slope in a layer. (See page(s) 396) |
| |
| |
| |
| solution | Usually slow but effective process of weathering and erosion in which rocks are dissolved by water. (See page(s) 401) |
| |
| |
| |
| stream | A moving body of water, confined in a channel and running downhill under the influence of gravity. (See page(s) 395) |
| |
| |
| |
| stream channel | A long, narrow depression, shaped and more or less filled by a stream. (See page(s) 396) |
| |
| |
| |
| stream gradient | Downhill slope of a stream’s bed or the water surface, if the stream is very large. (See page(s) 399) |
| |
| |
| |
| stream terrace | Steplike landform found above a stream and its flood plain. (See page(s) 423) |
| |
| |
| |
| stream velocity | The speed at which water in a stream travels. (See page(s) 398) |
| |
| |
| |
| superposed stream | A river let down onto a buried geologic structure by erosion of overlying layers. (See page(s) 424) |
| |
| |
| |
| suspended load | Sediment in a stream that is light enough in weight to remain lifted indefinitely above the bottom by water turbulence. (See page(s) 402) |
| |
| |
| |
| traction | Movement by rolling, sliding, or dragging of sediment fragments along a stream bottom. (See page(s) 402) |
| |
| |
| |
| trellis pattern | A drainage pattern consisting of parallel main streams with short tributaries meeting them at right angles. (See page(s) 397) |
| |
| |
| |
| tributary | a small stream flowing into a larger one. (See page(s) 396) |