Vannmettede

Vannmettede is a Norwegian adjective used to describe a material, most commonly soil or sediment, that is saturated with water. The term denotes that the pore spaces within the material are filled with water rather than air, corresponding to a volumetric water content equal to the material’s porosity under given pressure conditions. In geotechnical and hydrogeological contexts, the state of water saturation is often contrasted with unsaturated conditions, where air occupies part of the pores.

In soils, saturation occurs when drainage by gravity has filled all voids with water, typically at or near 100% saturation. The degree of saturation is quantified as S = theta / n, where theta is volumetric water content and n is porosity. Saturated soils exhibit high hydraulic conductivity (Ksat) and pore-water pressure responses governed by groundwater conditions. Waterlogged or saturated soils can have reduced shear strength and increased risk of settlement or liquefaction, especially under dynamic loading such as earthquakes.

Causes of water saturation include high rainfall, over-irrigation, perched water tables, and low drainage or low permeability substrates. In agriculture, prolonged saturation creates anaerobic soil conditions detrimental to many crops. In construction and engineering, temporary dewatering may be required at sites with saturated soils to maintain stability and support foundations.

In hydrology, the saturated zone lies below the water table and forms part of an aquifer system. Understanding the degree of water saturation is essential for predicting groundwater flow, drainage design, and the behavior of soils under load.