ytvattnet

Ytvattnet, in Swedish, literally means the surface water and is used in hydrology to refer to water bodies that exist on the Earth’s surface. It encompasses fresh and saline water in rivers, lakes, wetlands, coastal areas, and reservoirs, as distinct from groundwater (grundvatten). The term is used in environmental planning and water management to discuss the quantity, distribution, and quality of surface water resources.

Surface water is shaped by climate, topography, land cover, and human activity. It flows through rivers and streams, accumulates in lakes and reservoirs, and forms wetland ecosystems. It is affected by evaporation, precipitation, runoff, infiltration, and exchange with groundwater, resulting in seasonal and interannual variations in level, temperature, and chemistry. Water quality is assessed using parameters such as nutrients, dissolved oxygen, pH, turbidity, and pollutants.

In Sweden, management of ytvatnet involves national and local authorities under frameworks like the EU Water Framework Directive. Goals include achieving or maintaining good ecological and chemical status, protecting drinking water sources, and supporting recreation and biodiversity. Pressures on surface water include pollution, eutrophication, hydromorphological changes (such as damming and channel modification), overuse, and climate change, which can alter flow regimes and water temperature.

For researchers, planners, and the public, ytvatnet is a central concept for understanding freshwater availability, ecosystem health, and flood and drought risk. See also groundwater, surface water, hydrology, and water management.