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Wind Erosion Equation
A wind erosion equation is an equation used to design wind erosion control systems, which considers soil erodibility, soil roughness, climate, the unsheltered distance across a field, and the vegetative cover on the ground. E = f(I, K, C, L, V) The Wind Erosion Equation (WEQ) is a mathematical model used to estimate the potential average annual soil loss (E) from a field due to wind erosion. This equation incorporates several key variables: the Soil Erodibility Index (I), which measures the susceptibility of soil to erosion; the Soil Ridge Roughness Factor (K), reflecting the surface roughness and its impact on wind flow; the Climatic Factor (C), representing the influence of wind speed and frequency on erosion; the Unsheltered Median Travel Distance (L), indicating the distance over which wind can travel unimpeded across a field; and the Equivalent Quantity of Vegetative Cover (V), accounting for the protective effect of vegetation in reducing soil erosion. Together, these vari ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Erodibility
Erodability (or erodibility) is the inherent yielding or nonresistance of soils and rocks to erosion. A high erodability implies that the same amount of work exerted by the erosion processes leads to a larger removal of material. Because the mechanics behind erosion depend upon the competence and coherence of the material, erodability is treated in different ways depending on the type of surface that eroded. Soils Soil erodibility is a lumped parameter that represents an integrated annual value of the soil profile reaction to the process of soil detachment and transport by raindrops and surface flow. The most commonly used model for predicting soil loss from water erosion is the '' Universal Soil Loss Equation (USLE)'' (also known as the K-factor technique), which estimates the average annual soil loss A as: :A = R K L S C P where ''R'' is thrainfall erosivity factor ''K'' is the soil erodibility, ''L'' and ''S'' are topographic factors representing length and slope, and ''C'' and ' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aeolian Processes
Aeolian processes, also spelled eolian, pertain to wind activity in the study of geology and weather and specifically to the wind's ability to shape the surface of the Earth (or other planets). Winds may erode, transport, and deposit materials and are effective agents in regions with sparse vegetation, a lack of soil moisture and a large supply of unconsolidated sediments. Although water is a much more powerful eroding force than wind, aeolian processes are important in arid environments such as deserts. The term is derived from the name of the Greek god Aeolus, the keeper of the winds. Definition and setting ''Aeolian processes'' are those processes of erosion, transport, and deposition of sediments that are caused by wind at or near the surface of the earth. Sediment deposits produced by the action of wind and the sedimentary structures characteristic of these deposits are also described as ''aeolian''. Aeolian processes are most important in areas where there is little or ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Meteorology
Meteorology is a branch of the atmospheric sciences (which include atmospheric chemistry and physics) with a major focus on weather forecasting. The study of meteorology dates back millennia, though significant progress in meteorology did not begin until the 18th century. The 19th century saw modest progress in the field after weather observation networks were formed across broad regions. Prior attempts at prediction of weather depended on historical data. It was not until after the elucidation of the laws of physics, and more particularly in the latter half of the 20th century the development of the computer (allowing for the automated solution of a great many modelling equations) that significant breakthroughs in weather forecasting were achieved. An important branch of weather forecasting is marine weather forecasting as it relates to maritime and coastal safety, in which weather effects also include atmospheric interactions with large bodies of water. Meteorological pheno ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wind Speed
In meteorology, wind speed, or wind flow speed, is a fundamental atmospheric quantity caused by air moving from high to low pressure, usually due to changes in temperature. Wind speed is now commonly measured with an anemometer. Wind speed affects weather forecasting, aviation and maritime operations, construction projects, growth and metabolism rate of many plant species, and has countless other implications. Note that wind direction is usually almost parallel to isobars (and not perpendicular, as one might expect), due to Earth's rotation. Units Metres per second (m/s) is the SI unit for velocity and the unit recommended by the World Meteorological Organization for reporting wind speeds, and is amongst others used in weather forecasts in the Nordic countries. Since 2010 the International Civil Aviation Organization (ICAO) also recommends meters per second for reporting wind speed when approaching runways, replacing their former recommendation of using kilometres per h ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Von Kármán Constant
In fluid dynamics, the von Kármán constant (or Kármán's constant), named for Theodore von Kármán, is a dimensionless constant involved in the logarithmic law describing the distribution of the longitudinal velocity in the wall-normal direction of a turbulent fluid flow near a boundary with a no-slip condition. The equation for such boundary layer flow profiles is: :u=\frac\ln\frac, where ''u'' is the mean flow velocity at height ''z'' above the boundary. The roughness height (also known as roughness length) ''z0'' is where u appears to go to zero. Further ''κ'' is the von Kármán constant being typically 0.41, and u_\star is the friction velocity which depends on the shear stress ''τw'' at the boundary of the flow: :u_\star = \sqrt, with ''ρ'' the fluid density. The Kármán constant is often used in turbulence modeling, for instance in boundary-layer meteorology to calculate fluxes of momentum, heat and moisture from the atmosphere to the land surface. It is consider ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
