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Parameters of horizontal drainage Parameters of vertical drainage. The subsurface field drainage systems consist of horizontal or slightly sloping channels made in the soil; they can be open ditches, trenches, filled with brushwood and a soil cap, filled with stones and a soil cap, buried pipe drains, tile drains, or mole drains, but they can ...
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 ...
Subsurface drainage: Built by burying pipes underground to remove excess water from the soil profile. Subsurface drainage is widely used by farmers. It has many advantages: [5] It increases soil humidity and leads to better crop yields. It stops the accumulation of salts and gives farmers more flexibility to plant different types of crops.
Subsurface (groundwater) drainage for water table and soil salinity in agricultural land can be done by horizontal and vertical drainage systems. Horizontal drainage systems are drainage systems using open ditches or buried pipe drains. Vertical drainage systems are drainage systems using pumped wells, either open dug wells or tube wells.
Drainage criteria One would not want the water table to be too shallow to avoid crop yield depression nor too deep to avoid drought conditions. This is a subject of drainage research. The figure shows that a seasonal average depth of the water table shallower than 70 cm causes a yield depression [5]
The system should permit a small fraction of the irrigation water (about 10 to 20 percent, the drainage or leaching fraction) to be drained and discharged out of the irrigation project. [12] In irrigated areas where salinity is stable, the salt concentration of the drainage water is normally 5 to 10 times higher than that of the irrigation water.
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:, [4] [5]).
While this is a lesser issue for surface irrigation compared to other irrigation methods (due to the comparatively high leaching fraction), lack of subsurface drainage may restrict the leaching of salts from the soil. This can be remedied by drainage and soil salinity control through flushing.