Chemical hydrology
Chemical hydrology studies the composition and transformations of water as it moves through the atmosphere, soils, rocks, and surface waters.
Hydrologic cycle: The continuous circulation of water among the atmosphere, land, oceans, and living things. Water’s movement between reservoirs sets the pathways for chemical acquisition and transport.
Aqueous solution: A homogeneous mixture in which water acts as the solvent for dissolved substances. Natural waters are aqueous solutions whose composition chemical hydrology investigates.
Groundwater contamination: The presence of harmful substances in groundwater at concentrations that pose risks to health or the environment. Chemical transport and reactions determine contaminant persistence and spread underground.
Hydrochemical facies: A classification of groundwater based on its dominant dissolved ions and their relative proportions. Facies patterns summarize how geology and flow paths shape groundwater composition.
Chemical weathering: The alteration or dissolution of minerals through reactions with water, acids, and other chemical agents. Weathering releases dissolved ions into water moving through rocks and soils.
Chemical speciation: The distribution of an element among its chemical forms, including ions, complexes, and oxidation states. A total concentration alone does not reveal which forms of an element occur in water.
Acid mine drainage: Acidic, metal-rich drainage produced when sulfide minerals, especially pyrite, oxidize in exposed mine waste. It is a clear case of mineral reactions sharply altering water chemistry.
End-member mixing analysis: A method that estimates the proportions of distinct source waters in a mixed sample using chemical tracers. It separates contributions from sources such as rainfall, groundwater, and snowmelt.
Water–rock interaction: Chemical reactions between water and minerals that alter both the water’s composition and the rock. These reactions control many groundwater solutes and mineral changes.
Alkalinity: Water’s capacity to neutralize added acid, usually governed by bicarbonate, carbonate, and related bases. It indicates buffering capacity and helps interpret carbonate reactions in natural waters.