pórusvíz

Pore water refers to the water that occupies the pore spaces between solid grains in soils, sediments, and rocks. It is distinct from groundwater in that it is the water found in the voids of the pore structure, often at smaller scales and sometimes under unsaturated conditions. When pore spaces are fully saturated, the term pore water is closely related to formation water or groundwater, depending on the context.

Origin and composition: Pore water originates from infiltrating meteoric water and may also mix with water from adjacent formations or bodies. Its chemical composition is controlled by rock-water interactions, mineral dissolution and precipitation, ion exchange with clays, evaporation, and biological processes. Typical components include major ions such as calcium, magnesium, sodium, potassium, chloride, sulfate, and bicarbonate, as well as dissolved nutrients, organic matter, gases, and trace elements. In coastal or arid environments, salinity can vary widely, influencing pH and redox conditions.

Physical and chemical role: Pore water influences soil water potential, plant available water, and the mechanical behavior of soils through pore water pressure. Chemically, it governs nutrient availability, mineral stability, and the transport of contaminants. In sediments and rocks, pore-water chemistry records diagenetic history and ongoing geochemical processes.

Methods and applications: Pore water is sampled in situ with suction lysimeters, wick samplers, piezometers, or by extracting pore water from cores. Analyses typically include major ions, nutrients, dissolved organic carbon, isotopes, and dissolved gases. Applications span hydrology, soil science, environmental engineering, geochemistry, and petroleum geology, where pore-water data aid in understanding weathering, nutrient cycling, contaminant fate, saline intrusion, and reservoir quality.