In physical geography, a wetland is an environment at the interface between truly terrestrial ecosystems and aquatic systems making them inherently different from each other yet highly dependent on bo
th. In essence, wetlands are ecotones. Wetlands often host considerable biodiversity and endemism. The US Army Corps of Engineers and the US Environmental Protection Agency jointly define wetlands as: Those areas that are inundated or saturated by surface or ground water at a frequency and duration sufficient to support, and that under normal circumstances do support, a prevalence of vegetation typically adapted for life in saturated soil conditions. Wetlands generally include swamps, marshes, bogs, and similar areas.
Snow which contains a large amount of liquid water. If the water completely fills the air spaces which originally existed in the snow, it is classified as very wet snow.
Snow which contains a great deal of liquid water. If the water entirely fills the air spaces which originally existed in the snow, it is classified as very wet snow.
The set of points on a glacier separating the upper percolation zone, at higher elevation, from the lower percolation zone or wet-snow zone. The wet-snow line has no surface expression, but is signifi
cant as the upper limit of the region where internal accumulation may happen.
The part of the accumulation zone of a cold glacier or polythermal glacier where all of the snow reaches the melting point during the ablation season. The wet-snow zone is sometimes referred to as the
lower percolation zone.
The World Geodetic System (WGS) defines areference frame for the earth, for use in geodesy and navigation. The WGS84uses the zero meridian as defined by the Bureau International de l'Heure.
The World Geodetic System (WGS) defines a reference frame for the earth, for use in geodesy and navigation. The WGS84 uses the zero meridian as defined by the Bureau International de l'Heure.