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Definition
| Wearing away of rock by grinding action. |
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Term
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| A fan-shaped wedge of sediment that typically accumulates on land where a stream emerges from a steep canyon onto a flat area. In map view it has the shape of an open fan. Typically forms in arid or semiarid climates. |
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| The lower limit of erosion by a stream. Sea level is the ultimate base level. However, lakes can serve as a temporary base level in upstream areas. |
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| The larger, heavier particles that are being transported by a stream. Instead of being dissolved or suspended, these are being rolled or bounced along, spending at least part of their time in contact with the stream bottom. See also: load, suspended load, dissolved load. |
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Definition
| A measure of the total amount of sediment in a stream and the size of the particles being moved by the stream. |
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| A deposit of sediment that forms where a stream enters a standing body of water such as a lake or ocean. The name is derived from the Greek letter "delta" because these deposits typically have a triangular shape in map view. |
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Definition
| The volume of water in a flowing stream that passes a given location in a unit of time. Frequently expressed in cubic feet per second or cubic meters per second. Calculated by the formula Q = A x V where Q is the discharge, A is the cross sectional area of the channel and V is the average velocity of the stream. |
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Definition
| A ridge that separates two adjacent drainage basins. |
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Term
drainage basin or watershed [image] |
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Definition
| The geographic area that contributes runoff to a stream. It can be outlined on a topographic map by tracing the points of highest elevation (usually ridge crests) between two adjacent stream valleys. The watershed of a large river usually contains the watersheds of many smaller streams. Also referred to as a "drainage basin". |
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| A sudden rush of water, usually caused by a single cloudeburst over the narrow valley of a younge mountain stream. |
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| An area of alluvium-covered, relatively level land along the banks of a stream that is covered with water when the stream leaves its channel during a time of high flow. |
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Definition
| A miniature valley formes by erosion from heavy rains. |
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Definition
| The wearing away of land at the head of a gully or stream valley. |
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Definition
| A long continuous ridge built by people along the banks of a stream to contain the water during times of high flow. Natural levees can also be built along the banks of a stream. When the flood water decelerates upon leaving the channel, sediments quickly drop out of suspension and build a ridge over time. |
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Definition
| A stream that has many bends (meanders). This type of drainage pattern usually develops on a nearly level landscape and where the banks of the stream are easily eroded. |
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Definition
| A crescent-shaped lake that forms when a meandering stream changes course. Such changes in course frequently occur during flood events when overbank waters erode a new channel. |
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Definition
| A cylindrical or hemispherical hold in the bedrock of a stream that is formed from the continual swirling motion of sand and gravel by swirling currents. |
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Definition
| A chemical weathering process in which a material is dissolved. Also, the transport of dissolved ions by the water of a stream. |
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Definition
| The diversion of the upper part of one stream by the haedward growth of another stream. |
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Definition
| Transport of sediment by wind or water currents that are strong enough to keep the sediment particles continuously above the stream bottom or ground. (See traction and saltation for comparison.) |
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Definition
| A pass in a mountain ridge through which a stream flows. |
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