Concepts

The bidirectional exchange of water between groundwater aquifers and surface water bodies including streams, with groundwater contributing baseflow to streams and streams providing recharge to groundw...

Human-induced nitrogen input that has doubled biologically-available nitrogen on Earth

Major form of organic carbon across aquatic ecosystems, fueling stream metabolism and mediating key biogeochemical processes

The study of water cycling processes in mountainous terrain, including complex interactions between snowpack dynamics, topography, vegetation, and subsurface water storage

The degree to which water movement is facilitated or impeded through connected flow paths in subsurface sediments

Mineral formation from ascending hydrothermal solutions

Shallow subsurface zone where river and groundwater mix, serving as a source or sink of reactive nitrogen depending on water residence times and nitrogen transformation rates

Coupled modeling approach simulating surface and subsurface hydrologic processes including groundwater flow and particle tracking

Removal of nitrate from porewater through denitrification and other biogeochemical processes

Accounting framework where annual discharge equals precipitation minus evapotranspiration minus storage changes

Organic carbon derived from sedimentary rocks that is often poorly quantified and influences soil organic carbon composition, age, and stability

Modeling approach that couples transport processes with geochemical reactions to understand subsurface flow and chemical interactions

Spatial variability in biogeochemical processes and solute sources within watersheds, particularly between shallow soil zones and deeper groundwater zones

Oxidative dissolution of pyrite mineral producing sulfuric acid and iron oxides under oxic conditions

Microbial process where methane is oxidized under anoxic conditions, often coupled to reduction of alternative electron acceptors

The relationship between solute concentrations and discharge in streams, widely used as a metric for interpreting interaction of hydrological processes, chemical transport, and mineral reactions in wa...

The oxidation of ammonia to nitrate via nitrite, linking nitrogenous organic matter remineralization to nitrogen loss processes in the microbial N-cycle

Chemical and physical breakdown of sedimentary shale rocks through interactions with water, atmospheric gases, and biological processes

Areas of disproportionately high biogeochemical activity or export relative to surrounding landscape

The division of water flow between different hydrological pathways including surface flow, shallow subsurface flow, and deep groundwater flow

Spatial organization of aerobic and anaerobic zones based on dissolved oxygen availability that controls biogeochemical reactions

Redox-stratified and temporally dynamic sediments in river corridors where biological processes mediate sulfur transformations

Microbial reduction of sulfate coupled to organic matter oxidation in anoxic environments resulting in formation of low solubility sulfide minerals