出典:Wiktionary
throughflow (countable かつ uncountable, 複数形 throughflows)
出典:Wikipedia
出典:『Wikipedia』 (2011/03/13 22:16 UTC 版)
In hydrology, throughflow is the horizontal movement of water in the soil zone. This type of flow must first emerge on land before it enters a body of surface water (stream, lake, pond) to be considered throughflow (as opposed to interflow where the flow enters directly the body of surface water without having first emerged at the surface). Once water infiltrates the soil, it moves downwards under gravity and, because the soil becomes more compact and less permeable with increasing depth, will begin to move sideways at speeds of between 0.005 to 0.3 m/h. Throughflow usually happens when the soil is completely saturated with water. This water then flows underground until it reaches a river, lake, or ocean. The lowest rates of flow occur in heavy clay soils.