Hydrology is the study of the waters of the earth on and below the surface of the planet. Hydrology also involves the study of the various properties of water and its relationship with the living and nonliving environment. Areas of specialization within the Department include: surface and groundwater hydrology; watershed dynamics; hydrogeology; and ecosystem hydrology. Fields of application with hydrology include groundwater management and consulting; water pollution research and regulation; and hydrologic modeling and analysis.
A number of department researchers are involved in studies of catchment hydrology and hydrochemistry. Most of these studies combine field observations and laboratory measurements with modeling efforts. Topics under investigation include: evapotranspiration and land-atmosphere interaction; observations and modeling of runoff generation; stream-groundwater interaction and hyporheic zone processes; transport of agrichemicals in catchments; and biogeochemical cycling and acid deposition. The Shenandoah Watershed Study (SWAS) involves measurement of precipitation and stream-water properties to determine the concentration and flux of chemical material along hydrological pathways in the forested mountain watersheds of Shenandoah National Park and the western Virginia mountains.
Aqueous geochemists, hydrolgists, and microbial ecologists interact on a number of hydrogeological problems. Topics under investigation include: modeling of catchment hydrochemistry; bioremediation and biodegradation; solute, colloid, and bacterial transport through porous media; and modeling of groundwater flow, mass transport, and biogeochemical reactions. The Program of Interdisciplinary Research in Contaminant Hydrogeology (PIRCH) focuses on problems of contaminant hydrogeology, and involves researchers from Chemical and Civil Engineering.
Ecohydrology is the science, which relates hydrologic processes to ecosystem dynamics. This type of inquiry is fundamental to the understanding of the coupling existing between the water cycle and the biota. For example, Ecohydrology investigates the main hydrologic controls on the structure and function of terrestrial ecosystems. Some of these controls are exerted through the soil water balance, which mediates the impact of hydrologic processes on the dynamics of plant and soil microbial communities. Low values of soil moisture lead to the emergence of water stress conditions both in vegetation and in soil micro-organisms, thereby limiting the rates of photosynthesis, transpiration, microbial respiration, and soil organic matter decomposition. On the other hand, the anoxic conditions associated with soil saturation limit plant productivity, microbial decomposition, and mineralization, while providing favorable conditions for the biogenic emissions of nitrogen oxides (denitrification) and methane. Thus, the study of plant and microbial response to changes in hydrologic conditions requires the analysis of fluctuations both in root-zone soil moisture and in water table depth. Ecohydrology is also concerned with the biotic controls on hydrologic processes, including infiltration, runoff, water table dynamics, evapotranspiration and precipitation.
Land Atmosphere Interaction
Within the Department there is a strong focus on the interactions between the Earth’s surface and its atmosphere. These efforts integrate hydrological, ecological, and meteorological principles to understand the exchange of water, heat, and trace gases between the land and the atmosphere. Much of the interest in these mass and energy fluxes centers on the nonlinear feedback effects between the surface and the atmosphere, and the resulting impacts to the biosphere and atmosphere.