mettingsgrad

Mettingsgrad is a term used in some Scandinavian-language sources to denote the degree of saturation—the proportion of a porous medium’s pore space occupied by water. In English-language contexts the equivalent concept is degree of saturation, often abbreviated Sw.

Definition: Sw = Vw / Vv, where Vw is the volume of water in the pores and Vv is the total pore volume. Sw ranges from 0 to 1, corresponding to completely dry and fully saturated conditions, respectively.

Relation to moisture content: If θ is the volumetric water content and n is the porosity (the fraction of total volume that is pore space), Sw can be expressed as Sw = θ / n. This links measured soil moisture to the saturation state of the pore space.

Applications and measurement: Sw is foundational in soil physics, hydrology, and geotechnical engineering, influencing processes such as infiltration, drainage, capillary rise, and groundwater recharge. In practice, Sw is estimated through indirect methods like time-domain reflectometry (TDR), capacitance sensors, or gravimetric measurements, and is used in models of unsaturated flow such as Richards’ equation.

Notes: The spelling mettingsgrad appears as a variant of mättningsgrad or mættingsgrad in some Nordic languages, corresponding to the standard term degree of saturation. In English-language texts, the term degree of saturation is typically used, with Sw as the common symbol.