Isotope hydrology is a field of geochemistry and hydrology that uses naturally occurring stable and radioactive isotopic techniques to evaluate the age and origins of surface and groundwater and the processes within the atmospheric hydrologic cycle. Isotope hydrology applications are highly diverse, and used for informing water-use policy, mapping aquifers, conserving water supplies, assessing sources of water pollution, and increasingly are used in eco-hydrology to study human impacts on all dimensions of the hydrological cycle and ecosystem services.
Rain gardens, also called bioretention facilities, are one of a variety of practices designed to increase rain runoff reabsorption by the soil. They can also be used to treat polluted stormwater runoff. Rain gardens are designed landscape sites that reduce the flow rate, total quantity, and pollutant load of runoff from impervious urban areas like roofs, driveways, walkways, parking lots, and compacted lawn areas. Rain gardens rely on plants and natural or engineered soil medium to retain stormwater and increase the lag time of infiltration, while remediating and filtering pollutants carried by urban runoff. Rain gardens provide a method to reuse and optimize any rain that falls, reducing or avoiding the need for additional irrigation. A benefit of planting rain gardens is the consequential decrease in ambient air and water temperature, a mitigation that is especially effective in urban areas containing an abundance of impervious surfaces that absorb heat in a phenomenon known as the heat-island effect.
Surface runoff is the unconfined flow of water over the ground surface, in contrast to channel runoff. It occurs when excess rainwater, stormwater, meltwater, or other sources, can no longer sufficiently rapidly infiltrate in the soil. This can occur when the soil is saturated by water to its full capacity, and the rain arrives more quickly than the soil can absorb it. Surface runoff often occurs because impervious areas do not allow water to soak into the ground. Furthermore, runoff can occur either through natural or human-made processes.
Runoff is the flow of water across the earth, and is a major component in the hydrological cycle. Runoff that flows over land before reaching a watercourse is referred to as surface runoff or overland flow. Once in a watercourse, runoff is referred to as streamflow, channel runoff, or river runoff. Urban runoff is surface runoff created by urbanization.
Baseflow is the portion of the streamflow that is sustained between precipitation events, fed to streams by delayed pathways. It should not be confused with groundwater flow. Fair weather flow is also called base flow.
An hydrological transport model is a mathematical model used to simulate the flow of rivers, streams, groundwater movement or drainage front displacement, and calculate water quality parameters. These models generally came into use in the 1960s and 1970s when demand for numerical forecasting of water quality and drainage was driven by environmental legislation, and at a similar time widespread access to significant computer power became available. Much of the original model development took place in the United States and United Kingdom, but today these models are refined and used worldwide.
Groundwater recharge or deep drainage or deep percolation is a hydrologic process, where water moves downward from surface water to groundwater. Recharge is the primary method through which water enters an aquifer. This process usually occurs in the vadose zone below plant roots and is often expressed as a flux to the water table surface. Groundwater recharge also encompasses water moving away from the water table farther into the saturated zone. Recharge occurs both naturally and through anthropogenic processes, where rainwater and or reclaimed water is routed to the subsurface.
Generalized likelihood uncertainty estimation (GLUE) is a statistical method used in hydrology for quantifying the uncertainty of model predictions. The method was introduced by Keith Beven and Andrew Binley in 1992. The basic idea of GLUE is that given our inability to represent exactly in a mathematical model how nature works, there will always be several different models that mimic equally well an observed natural process. Such equally acceptable or behavioral models are therefore called equifinal.
Stream restoration or river restoration, also sometimes referred to as river reclamation, is work conducted to improve the environmental health of a river or stream, in support of biodiversity, recreation, flood management and/or landscape development.
A hydrologic model is a simplification of a real-world system that aids in understanding, predicting, and managing water resources. Both the flow and quality of water are commonly studied using hydrologic models.
Low-impact development (LID) is a term used in Canada and the United States to describe a land planning and engineering design approach to manage stormwater runoff as part of green infrastructure. LID emphasizes conservation and use of on-site natural features to protect water quality. This approach implements engineered small-scale hydrologic controls to replicate the pre-development hydrologic regime of watersheds through infiltrating, filtering, storing, evaporating, and detaining runoff close to its source. Green infrastructure investments are one approach that often yields multiple benefits and builds city resilience.
Socio-hydrology; socio and hydrology is an interdisciplinary field studying the dynamic interactions and feedbacks between water and people. Areas of research in socio-hydrology include the historical study of the interplay between hydrological and social processes, comparative analysis of the co-evolution and self-organization of human and water systems in different cultures, and process-based modelling of coupled human-water systems. The first approach to socio-hydrology was the term "hydro-sociology", which arises from a concern about the scale of impact of human activities on the hydrological cycle. Socio-hydrology is defined as the humans-water interaction and later as “the science of people and water”, which introduces bidirectional feedbacks between human–water systems, differentiating it from other related disciplines that deal with water. Furthermore, socio-hydrology has been presented as one of the most relevant challenges for the Anthropocene, in relationship with its aims at unraveling dynamic cross-scale interactions and feedbacks between natural and human processes that give rise to many water sustainability challenges. Socio‐hydrology is also predicted to be an important license for modellers.
Hydrogeomorphology has been defined as “an interdisciplinary science that focuses on the interaction and linkage of hydrologic processes with landforms or earth materials and the interaction of geomorphic processes with surface and subsurface water in temporal and spatial dimensions.” The term 'hydro-geomorphology’ designates the study of landforms caused by the action of water. By this definition hydro-geomorphology is inseparable part of geomorphology moreover fluvial geomorphology, because water is one of the most important agents in forming and shaping of landforms. From the groundwater point of view integration of geological, structural and hydrological data with hydro-geomorphologic data is very much useful in finding out the groundwater potential zones with fruitful results. The science relating to the geographical, geological, and hydrological aspects of water bodies and to changes to these aspects in response to low variations and to natural and human caused events, such as heavy rainfall or channel straightening is the hydro-geomorphology.
Murugesu Sivapalan is an Australian-American engineer and hydrologist of Sri Lankan Tamil origin and a world leader in the area of catchment hydrology. He is currently the Chester and Helen Siess Endowed Professor of Civil and Environmental Engineering, and professor of Geography & Geographic Information Science, at the University of Illinois, Urbana-Champaign. Sivapalan is widely recognized for his fundamental research on scale issues in hydrological modeling, his leadership of global initiatives aimed at hydrologic predictions in ungauged basins, and for his role in launching the new sub-field of socio-hydrology.
Legacy sediment (LS) is depositional bodies of sediment inherited from the increase of human activities since the Neolithic. These include a broad range of land use and land cover changes, such as agricultural clearance, lumbering and clearance of native vegetation, mining, road building, urbanization, as well as alterations brought to river systems in the form of dams and other engineering structures meant to control and regulate natural fluvial processes (erosion, deposition, lateral migration, meandering). The concept of LS is used in geomorphology, ecology, as well as in water quality and toxicological studies.
Terri S. Hogue is an American hydrologist. She is currently a professor and department head of Civil and Environmental Engineering at Colorado School of Mines. Her research focuses on different hydrologic and land surface processes in semi-arid regions and the implications of them on water resource management.
Kamini Singha is a Professor in the department of Geology and Geological Engineering at the Colorado School of Mines, where she works on questions related to hydrogeology.
Dörthe Tetzlaff is a German hydrologist who is Professor of Ecohydrology at Humboldt University zu Berlin and Head of Department at the Leibniz-Institute of Freshwater Ecology and Inland Fisheries, Berlin, Germany, since 2017. Tetzlaff was appointed Fellow of the Royal Society of Edinburgh in 2017, Fellow of the American Geophysical Union in 2018, Honorary Fellow of the Geological Society of America in 2019, Fellow of the European Academy of Sciences in 2022 and Member of the Berlin-Brandenburg Academy of Sciences and Humanities in 2023.
Carol Kendall is a hydrologist known for her research tracking nutrients and contaminants in aquatic ecosystems using isotopic tracers.
Watershed delineation is the process of identifying the boundary of a watershed, also referred to as a catchment, drainage basin, or river basin. It is an important step in many areas of environmental science, engineering, and management, for example to study flooding, aquatic habitat, or water pollution.
