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Typically on straight road sections, the drainage gradient is at least 1–3% due to the normal cross slope of 1–3%. In curved sections the drainage gradient is higher, and may often reach 5–12% due to superelevated CS that may reach 5–8% in areas with icy roads and up to 12% in areas without icy roads.
the permissible long term average depth of the water table (Dw) on the basis of agricultural drainage criteria; the soil's hydraulic conductivity (Ka and Kb) by measurements; the depth of the bottom of the aquifer (Di) the design drain spacing (L) can be found from the equation in dependence of the drain depth (Dd) and drain radius (r ...
A function W is a watershed of a function F if and only if W ≤ F and W preserves the contrast between the regional minima of F; where the contrast between two regional minima M 1 and M 2 is defined as the minimal altitude to which one must climb in order to go from M 1 to M 2. [7] An efficient algorithm is detailed in the paper. [8] Watershed ...
Watershed delineation is the process of identifying the boundary of a watershed, also referred to as a catchment, drainage basin, or river basin.It is an important step in many areas of environmental science, engineering, and management, for example to study flooding, aquatic habitat, or water pollution.
l = slope length α = angle of inclination. The grade (US) or gradient (UK) (also called stepth, slope, incline, mainfall, pitch or rise) of a physical feature, landform or constructed line refers to the tangent of the angle of that surface to the horizontal. It is a special case of the slope, where zero indicates horizontality. A larger number ...
Cross slope is the angle around a vertical axis between: the horizontal line that is perpendicular to the road's center line, and; the surface. Typical values range from 2 percent for straight segments to 10 percent for sharp superelevated curves. It may also be expressed as a fraction of an inch in rise over a one-foot run (e.g. 1 ⁄ 4 inch ...
Drainage density relates to the storage and runoff terms. Drainage density relates to the efficiency by which water is carried over the landscape. Water is carried through channels much faster than over hillslopes, as saturated overland flow is slower due to being thinned out and obstructed by vegetation or pores in the ground. [7]
The world average river reach slope is 2.6 m/km or 0.26%; [2] a slope smaller than 1% and greater than 4% is considered gentle and steep, respectively. [3] Stream gradient may change along the stream course. An average gradient can be defined, known as the relief ratio, which gives the average drop in elevation per unit length of river. [4]