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Drainage design procedures. When the land needs a subsurface drainage system, but saline groundwater is present at great depth, it is better to employ a shallow, closely spaced system of pipes or ditches instead of a deep, widely spaced system. The reason is that the deeper systems produce a more salty effluent than the shallow systems.
Tile drainage. Tile drainage is a form of agricultural drainage system that removes excess sub-surface water from fields to allow sufficient air space within the soil, proper cultivation, and access by heavy machinery to tend and harvest crops. While surface water can be drained by pumping, open ditches, or both, tile drainage is often the most ...
In geotechnical engineering, watertable control is the practice of controlling the height of the water table by drainage.Its main applications are in agricultural land (to improve the crop yield using agricultural drainage systems) and in cities to manage the extensive underground infrastructure that includes the foundations of large buildings, underground transit systems, and extensive ...
Water table. Cross-section of a hillslope depicting the vadose zone, capillary fringe, water table, and the phreatic or saturated zone. (Source: United States Geological Survey.) The water table is the upper surface of the zone of saturation. The zone of saturation is where the pores and fractures of the ground are saturated with groundwater ...
A drainage equation is an equation describing the relation between depth and spacing of parallel subsurface drains, depth of the watertable, depth and hydraulic conductivity of the soils. It is used in drainage design. Parameters in Hooghoudt's drainage equation. A well known steady-state drainage equation is the Hooghoudt drain spacing equation.
Spacing equations of subsurface drains and the groundwater energy balance applied to drainage equations [5] are examples of two-dimensional groundwater models. Three-dimensional models like Modflow [6] require discretization of the entire flow domain. To that end the flow region must be subdivided into smaller elements (or cells), in both ...
The water cycle (or hydrologic cycle or hydrological cycle), is a biogeochemical cycle that involves the continuous movement of water on, above and below the surface of the Earth. The mass of water on Earth remains fairly constant over time. However, the partitioning of the water into the major reservoirs of ice, fresh water, salt water and ...
In the same fashion, the well drainage requirement can be found from well discharge (Wel) in the geohydrologic water balance or the overall water balance. The subsurface drainage requirement and well drainage requirement play an important role in the design of agricultural drainage systems (references:,).