A raft is any flat structure for support or transportation over water. It is usually of basic design, characterized by the absence of a hull . Rafts are usually kept afloat by using any combination of buoyant materials such as wood , sealed barrels , or inflated air chambers (such as pontoons ), and are typically not propelled by an engine. Rafts are an ancient mode of transport; naturally-occurring rafts such as entwined vegetation and pieces of wood have been used to traverse water since the dawn of humanity.
18-874: The Dry Fork is a 39.1-mile-long (62.9 km) tributary of the Black Fork of the Cheat River in the Allegheny Mountains of eastern West Virginia , USA. Via the Black Fork, the Cheat, and the Monongahela and Ohio rivers, it is part of the watershed of the Mississippi River . The Dry Fork flows for much of its length in the Monongahela National Forest and drains mostly rural and forested areas. It
36-440: A cataract into another becomes the upper fork, and the one it descends into, the lower ; or by relative volume: the smaller stream designated the little fork, the larger either retaining its name unmodified, or receives the designation big . Tributaries are sometimes listed starting with those nearest to the source of the river and ending with those nearest to the mouth of the river . The Strahler stream order examines
54-464: A lake . A tributary does not flow directly into a sea or ocean . Tributaries, and the main stem river into which they flow, drain the surrounding drainage basin of its surface water and groundwater , leading the water out into an ocean. The Irtysh is a chief tributary of the Ob river and is also the longest tributary river in the world with a length of 4,248 km (2,640 mi). The Madeira River
72-409: A tree data structure . Raft Traditional or primitive rafts were constructed of wood, bamboo or reeds ; early buoyed or float rafts use inflated animal skins or sealed clay pots which are lashed together. Modern float rafts may also use pontoons , drums , or extruded polystyrene blocks. Depending on its use and size, it may have a superstructure , masts, or rudders. Timber rafting
90-406: A West Fork as well (now filled in). Forks are sometimes designated as right or left. Here, the handedness is from the point of view of an observer facing upstream. For instance, Steer Creek has a left tributary which is called Right Fork Steer Creek. These naming conventions are reflective of the circumstances of a particular river's identification and charting: people living along the banks of
108-414: A forking of the stream to the right and to the left, which then appear on their charts as such; or the streams are seen to diverge by the cardinal direction (north, south, east, or west) in which they proceed upstream, sometimes a third stream entering between two others is designated the middle fork; or the streams are distinguished by the relative height of one to the other, as one stream descending over
126-439: A river, with a name known to them, may then float down the river in exploration, and each tributary joining it as they pass by appears as a new river, to be given its own name, perhaps one already known to the people who live upon its banks. Conversely, explorers approaching a new land from the sea encounter its rivers at their mouths, where they name them on their charts, then, following a river upstream, encounter each tributary as
144-533: Is the largest tributary river by volume in the world with an average discharge of 31,200 m /s (1.1 million cu ft/s). A confluence , where two or more bodies of water meet, usually refers to the joining of tributaries. The opposite to a tributary is a distributary , a river or stream that branches off from and flows away from the main stream. Distributaries are most often found in river deltas . Right tributary , or right-bank tributary , and left tributary , or left-bank tributary , describe
162-471: Is used by the logging industry for the transportation of logs, by tying them together into rafts and drifting or pulling them down a river. This method was very common up until the middle of the 20th century but is now used only rarely. Large rafts made of balsa logs and using sails for navigation were important in maritime trade on the Pacific Ocean coast of South America from pre-Columbian times until
180-789: The Laurel Fork , which joins it in Randolph County, and the Glady Fork , which joins it in Tucker County. Both of these are also considered principal tributaries of the Cheat River. Red Creek — which enters Dry Fork at the town of Dryfork — drains much of the Dolly Sods Wilderness area. Tributary A tributary , or an affluent , is a stream or river that flows into a larger stream ( main stem or "parent" ), river, or
198-559: The 19th century. Voyages were made to locations as far away as Mexico, and many trans-Pacific voyages using replicas of ancient rafts have been undertaken to demonstrate possible contacts between South America and Polynesia . The type of raft used for recreational rafting is almost exclusively an inflatable raft , manufactured of flexible materials for use on whitewater . In biology , particularly in island biogeography , non-manmade rafts are an important concept. Such rafts consist of matted clumps of vegetation that has been swept off
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#1732855762196216-407: The arrangement of tributaries in a hierarchy of first, second, third and higher orders, with the first-order tributary being typically the least in size. For example, a second-order tributary would be the result of two or more first-order tributaries combining to form the second-order tributary. Another method is to list tributaries from mouth to source, in the form of a tree structure , stored as
234-592: The dry land by a storm , tsunami , tide , earthquake or similar event; in modern times they sometimes also incorporate other kind of flotsam and jetsam , e.g. plastic containers. They stay afloat by its natural buoyancy and can travel for hundreds, even thousands of miles and are ultimately destroyed by wave action and decomposition , or make landfall. Rafting events are important means of oceanic dispersal for non-flying animals. For amphibians , reptiles , and small mammals , in particular, but for many invertebrates as well, such rafts of vegetation were often
252-693: The midpoint. In the United States, where tributaries sometimes have the same name as the river into which they feed, they are called forks . These are typically designated by compass direction. For example, the American River in California receives flow from its North, Middle, and South forks. The Chicago River 's North Branch has the East, West, and Middle Fork; the South Branch has its South Fork, and used to have
270-428: The orientation of the tributary relative to the flow of the main stem river. These terms are defined from the perspective of looking downstream, that is, facing the direction the water current of the main stem is going. In a navigational context, if one were floating on a raft or other vessel in the main stream, this would be the side the tributary enters from as one floats past; alternately, if one were floating down
288-510: The towns of Whitmer , Job , and Harman . After it enters Tucker County (at Dryfork ) it turns to the northwest and flows to the town of Hendricks , where it meets the Blackwater River to form the Black Fork . Gandy Creek — which passes through the well-known cave known as the " Sinks of Gandy " — joins Dry Fork at the town of Gandy. In the lower part of its course the Dry Fork collects
306-472: The tributary, the main stream meets it on the opposite bank of the tributary. This information may be used to avoid turbulent water by moving towards the opposite bank before approaching the confluence. An early tributary is a tributary that joins the main stem river closer to its source than its mouth, that is, before the river's midpoint ; a late tributary joins the main stem further downstream, closer to its mouth than to its source, that is, after
324-606: Was traditionally considered one of the five Forks of Cheat . According to the Geographic Names Information System , Dry Fork has also been known historically as Dry Run . The stream's name derives from the occurrence of underground passages through which portions of the stream flow, leaving a dry streambed on the surface at times during the year. (See Sinks of Gandy ) The Dry Fork rises between Rich Mountain and Little Middle Mountain in eastern Randolph County and initially flows north-northeastwardly, past
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