watersaturated

Watersaturated, or water-saturated, describes a condition of a porous material in which all void spaces are filled with liquid water rather than air. It is a common state in soils, rocks, and building materials when the pore network is completely water-filled, such as below the groundwater table or after prolonged infiltration.

Degree of saturation (Sr) is the fraction of pore volume filled with water; Sr = 1 indicates full saturation. It relates to volumetric water content theta and porosity n by theta = Sr × n, so full saturation occurs when theta equals porosity. Saturation can be temporary during rainfall events or long-term in aquifers. In many soils, capillary forces maintain unsaturated conditions above the water table, while saturated conditions prevail below it.

Hydraulic and mechanical properties differ between saturated and unsaturated states. In saturated conditions, Darcy's law governs flow with saturated hydraulic conductivity; pore water pressure contributes to effective stress. Saturation also affects strength, stability, and transport; for example, saturated soils can transmit higher pore pressures during loading and may liquefy in seismic events. Measurement methods include core sampling with gravimetric tests, time-domain reflectometry, neutron scattering, and borehole piezometers to determine theta, n, and Sr.

Applications and contexts include agriculture and hydrology, geotechnical engineering, hydrogeology, and material science. Understanding saturation is important for irrigation planning, groundwater recharge, construction in floodplains, and assessing swelling clays or capillary rise.