Chapter 6 Vocab

Vocab Chapter 6: Floods/ Streams Hydrosphere- all the water at and near the surface of the earth Hydrologic cycle- precipitation, condensation, evaporation Stream- any body of flowing water confined within a channel, regardless of size Drainage basin- region from which a stream drains water Discharge- the volume of water moving past a specific point Sediment transport: Traction load- the denser, heavier pieces that roll around the bottom Saltation- small hops along the stream bed Bed load- all material that is moved by the stream Suspended load- load suspended in the stream (lightweight) Dissolved load- material that has been chemically dissolved in the water Load- total quantity of material that a stream transports Capacity- measure of a total load of material that a stream can move Gradient- steepness of the stream channel Base level- lowest elevation at which the stream can erode downward Longitudinal profile- sketch of a streams elevation from source to mouth Well sorted- materials deposited at a given point tending to be similar in size or weight Delta- large, fan shaped pile of sediment at the foot of a river Alluvial fan- shaped like a delta; formed when a tributary stream flows into a more slowly flowing, larger stream, or a stream flows from mountains into a plain Meanders- bends in the stream Point bars- sediment deposited on the insides of meanders Cut banks- eroded, enlarged, and shifted part of the edge bank where water flows somewhat faster Braided stream- a complex pattern of many channels that divide and rejoin, shifting through sediment Flood plain- broad flat area covered with sediment around the stream proper, where streams spill onto during floods Oxbows- a cut off meander Flood- a stream overflowing its? banks Infiltration- water sinking into ground Percolation- process of moving water through soil and rock Stage- elevation of water stream at any given point Crest- when the maximum stage is reached Upstream floods- floods that only affect small, localized areas Downstream floods- floods that affect large stream systems and large drainage basins Hydrograph- a graph of the fluctuations of a stream stage or discharge Flood frequency curve- a record of flood frequency Recurrence interval- how frequently, on average, a flood of a certain severity occurs Retention ponds- large basins that trap surface run off Diversion channels Channelization- various modifications of the stream channel itself that are usually intended to raise the velocity of water flow Levee- raised banks along a stream channel Rill- water flow not in a channel