Water Quality and Resources
Water quality and resources concerns the chemical and biological condition of fresh water and the assessment, allocation, and management of water as a finite resource under competing demands and changing climate.
Definition
Water quality and resources is the branch of hydrology concerned with the condition (chemical, physical, and biological quality) and the availability, allocation, and sustainable management of fresh water, including its scarcity and its role in ecosystems.
Scope
This area covers the hydrological controls on water quality and the transport of solutes and pollutants, the management and allocation of surface and groundwater resources, the analysis of drought and water scarcity, and the interactions between water and ecosystems (ecohydrology). It is the applied, resource- and quality-oriented part of hydrology, drawing on the physical processes developed in the other areas.
Sub-topics
Core questions
- How do hydrological processes control the quality of surface and groundwater?
- How are water resources assessed, allocated, and managed among competing uses?
- What drives drought and water scarcity, and how are they characterized and managed?
- How do water availability and flow regimes shape ecosystems, and vice versa?
Key concepts
- Water quality and solute transport
- Renewable freshwater and water stress
- Water allocation and management
- Drought indices and scarcity
- Environmental and ecological flows
- Ecohydrology
Key theories
- Global water resources and scarcity
- Assessments combine renewable freshwater fluxes with population and demand to map water availability and stress, showing that scarcity is driven jointly by climate variability and by growing human withdrawals.
- Integrated water resources management
- Water resources are managed as coupled surface-groundwater systems serving multiple, often competing, uses, requiring allocation rules, storage, and quality protection within a basin-scale, integrated framework.
Clinical relevance
This area underpins the protection of drinking-water sources, the regulation of pollutant discharges, the planning of reservoirs and inter-basin transfers, drought monitoring and response, and the maintenance of environmental flows for aquatic ecosystems, all increasingly stressed by population growth and climate change.
History
As surface- and ground-water sciences matured, attention broadened from water quantity to quality and to the management of water as a scarce resource. Late-20th-century global assessments quantified water stress and its vulnerability to climate change and population growth, while ecohydrology emerged to link hydrological regimes with ecosystems.
Key figures
- David R. Maidment
- Charles J. Vorosmarty
- Taikan Oki
Related topics
Seminal works
- maidment1993
- oki2006
- vorosmarty2000
Frequently asked questions
- Is the world running out of fresh water?
- Globally, fresh water is renewed by the water cycle, but it is unevenly distributed in space and time, so many regions experience scarcity where demand exceeds locally available supply, a stress intensified by population growth, pollution, and climate change.
- How is hydrology related to water quality?
- Hydrological processes control how much water is available to dilute and transport substances, how fast solutes and pollutants move, and how they mix between surface and groundwater, so flow and quality are tightly coupled in any water body.