Some of these were obtained, or altered from the (Wikipedia entry on Streams)
Spring - The point at which a stream emerges from an underground course through unconsolidated sediments or through caves. A stream can, especially with caves, flow aboveground for part of its course, and underground for part of its course.
Swalette - The portion of a disappearing stream where the water drains into a sinkhole into an aquifer or subterranean cave or culvert; characteristic of Karst hydrology and topography. This system may return to the surface at a spring.
Source - The spring from which the stream originates, or other point of origin of a stream.
Headwaters - The part of a stream or river proximate to its source. The word is most commonly used in the plural where there is no single point source.
Confluence - The point at which the two streams merge. If the two tributaries are of approximately equal size, the confluence may be called a fork.
Run - A somewhat smoothly flowing segment of the stream.
Pool - A segment where the water is deeper and slower moving.
Riffle - A segment where the flow is shallower and more turbulent.
Channel - A depression created by constant erosion that carries the stream's flow.
Floodplain - Lands adjacent to the stream that are subject to flooding when a stream overflows its banks.
Stream bed - The bottom of a stream.
Gauging station - A point of demarkation along the route of a stream or river, used for reference marking or water monitoring.
Thalweg - The river's longitudinal section, or the line joining the deepest point in the channel at each stage from source to mouth.
Wetted perimeter - The line on which the stream's surface meets the channel walls.
Nickpoint - The point on a stream's profile where a sudden change in stream gradient occurs.
Waterfall or cascade - The fall of water where the stream goes over a sudden drop called a nickpoint; some nickpoints are formed by erosion when water flows over an especially resistant stratum, followed by one less so. The stream expends kinetic energy in "trying" to eliminate the nickpoint.
Mouth - The point at which the stream discharges, possibly via an estuary or delta, into a static body of water such as a lake or ocean
Meander - The natural bending and winding of a section of river; usually indicative of a mature or old, established feature. Meandering is the result of water's mechanics of erosion, sediment transportation. Faster, turbid water has a higher capacity to carry load, whereas the same water column will drop its load when it slows. As a stream approaches a turn in a watercourse, water will flow more slowly along the inside shoreline where sediment load is dropped and deposition occurs. Conversely, water moves faster along the outer edge, where undercutting and erosion of the shoreline occur, which can be deposited downstream. Over time, this process deviates the section of river laterally (from the stream run), creating a turn which can occur in succession along a watercourse.
Oxbow Lake - A relic of a stream meander which has exceeded its maximum potential to change course. A meander eventually erodes through neighboring shorelines to connect again as a straight, shorter stream run. This process leaves a closed segment of the meander's previous course as a non-flowing U-shaped lake to the side of the current stream. Over a long period of geologic time, a floodplain may exhibit signs of meander scarring, where many iterations of sinuous variation have occured.
Temporal Establishment:
Perennial - Established waterbodies, present throughout a year under a normal hydroperiod
Intermittent - A stream that is present for most of the year, which stops flowing for weeks or months at a time
Ephemeral - Short lived features, usually flowing after significant precipitation events
Winterbourne - A stream which flows only during winter months and is dry during the summer (dry season)
Drainage Patterns:
Images courtesy Michael E. Ritter. Read more about these drainage patterns in his free e-book: The Physical Environment: an Introduction to Physical Geography
Dendritic - A very common branching fractal pattern found nature that can also be found in leaves, branches, tree roots, and veins to name a few.
Large scale example in Apalachee Bay south of St. Marks, Florida (be sure to zoom in and out, and pan to the east for a few miles to observe the varying scales in which these patterns exist in nature)
Smaller scale example showing the confluence in Pensacola Bay in western Florida
Dendritic drainage pattern
Parallel - Similar to dendritic features, but the branches are skewed to run more or less in a similar direction influenced by changes in elevation
Parallel drainage pattern
Trellis -Read more about this pattern here.
Trellis drainage pattern
Rectangular - Read more about this pattern here.
Rectangular drainage pattern
Radial - Caused by centrally located elevated land forms; from uplift, volcanoes, or other geological phenomena.
Radial drainage pattern
Centripetal - Caused by centrally located depression in geography which can drain into a number of features including a depressional wetland, a swalette in a disappearing stream, an intermittent or ephemeral lake which can leave a salt flats in the dry lake bed, etc.
Centripetal drainage pattern
Deranged - A sign of significant disturbance of historically established features.
Deranged drainage pattern
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