J k karst is a type of topography or large scale

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Unformatted text preview: K Karst is a type of topography or large-scale landform characterized by numerous collapse structures visible at the surface as spring or cave openings and sinkholes, and in the subsurface as caves and smaller solution openings that provide underground drainage; the closed depressions and collapse structures that dot a karst landscape are the result of chemical weathering by dissolution of carbonate rocks, principally limestone and dolomite, and less commonly of evaporate rocks, especially gypsum and anhydrite, in areas of arid and semiarid climate. Noteworthy limestone areas of karst topography in the United States are the karst plains and landscapes of Kentucky, the Ozark Plateau of southern Missouri and northern Arkansas, and the karst plain of northwestern Florida. Kinematic viscosity, the ratio of the viscosity coefficient to density of a liquid, is a measure of the ability of streamflow to entrain and transport sediment. Knickpoint is any interruption or break of a channel gradient, especially a headcut site of abrupt change or inflection in the longitudinal profile of a stream channel or its valley. Krotovina, a soils term of Russian origin, is a once-open irregular tubular structure or chamber made by a burrowing animal, such as a pocket gopher, that subsequently has filled with sediment from above. 27 L Lacustrine refers to any feature formed or caused by the processes of a lake; thus, a body of lacustrine sediment (lake beds) is typically one of mostly fine fluvial sediment that dropped from suspension as and while the silt-laden streamflow was ponded as lake water. Laminar flow, as a hydrologic term, is water movement (flow) in which the lines of flow are essentially constant and in which flow direction at all sites remains nearly unchanged through time; laminar flow is typical of most ground-water movement whereas most concentrated flows of stream channels are turbulent. . Lentic refers to or relates to still or sluggish water such as lakes, ponds, and swamps; lentic species are organisms that live in still or sluggish water. Levee (natural) of a stream channel is a broad, low ridge or embankment of coarse silt and sand that is deposited by a stream on its flood plain and along either bank of its channel; natural levees are formed by reduced velocity of flood flows as they spill onto flood-plain surfaces and can no longer transport the coarse fraction of the suspended-sediment load. Especially along meandering streams, natural levees may be of mappable areal extent; they tend to be relatively thin bands of silt and sand sloping gently down-valley from the down-valley bank of the channel from that portion of a meander crossing the valley floor. Loam is a porous, permeable soil comprised of similar proportions of clay, silt, and sand; loams generally contain humus (decomposed organic matter) and may have a minor amount of gravel. Loess is a wind-deposited accumulation of terrestrial clastic sediment generally of coarse-clay to fine-sand sizes but mostly silt; loess bodies tend to be highly erodible, unstratified, and are mostly derived by deflation and re-deposition of fine, quartzitic sediment from poorly protected surfaces of till, glacial outwash, fluvial-overbank and lake-bed deposits, and deserts. Lotic refers to or relates to moving water, especially streamflow; lotic species are organisms that live in moving water. M Manning equation is an empirical formula relating stream velocity to controlling variables; when channel width and depth are included, the simplified formula (in metric units) is expressed in terms of discharge, Q: Q = [1/n] G1/2 W D5/3, in which n is the roughness coefficient, G is channel gradient, W is channel width, and D is mean channel depth. For hydraulic computations, the formula is usually expressed as Q = [1/n] A R2/3 S1/2, in which n is the roughness coefficient, A is cross-sectional area, R is hydraulic radius, and S is the energy slope of the reach. Mass movement is any downslope transfer, through gravitational (inertial) and generally water-facilitated (viscous) processes, of near-surface soil and rock material; rates of mass movement range from very slow creep to nearly instantaneous slope failure. 28 Mass wasting is the failure and movement by gravity of a volume of soil, alluvium, rock, or ice to a downslope site storage; it the result of the process of mass movement. Mean annual flood is the average flood discharge (m3 s-1) for a specified period or number of years. Meander of a stream is one of a series of regular, sharp, freely developing, and sinuous curves, bends, loops, turns, or windings in the course of a stream; the process of stream meandering is a means of channel-gradient adjustment through sorting of stored sediment by erosion at the outside of a bend and deposition, as a point bar, at the inside of the bend. Meander belt is that area of an alluvial bottomland defined by lines, on both sides of the zone of activity, drawn tangentially along the points of maximum horizontal extent of the various meanders in a sequence of meanders. Measure...
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This document was uploaded on 02/26/2014 for the course ES 322 at Western Oregon University.

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