Veelevik

Veelevik is a term used in hydrology and geography to describe the spatial extent of floodwaters at a given moment. The word is derived from Estonian roots vee, meaning water, and levik, meaning spread or distribution, and is sometimes employed in Estonian-language flood studies and regional risk assessments to discuss how far floodwaters reach during an event.

In formal terms, the veelevik at time t can be defined as the set of locations x where water depth h(x,t) exceeds a chosen threshold h0. This conceptualization highlights both the size and shape of flooded areas and how they evolve as rainfall, snowmelt, or storm surge change hydrological conditions. The precise threshold and the resulting shape of the veelevik can vary with the purpose of the analysis and the available data.

Data and methods used to estimate veelevik include satellite and radar imagery, in situ gauge measurements, LiDAR-derived topography, drone surveys, and hydrodynamic or rainfall-runoff models. Modern flood forecasting often produces time-varying veelevik maps to accompany warnings, planning, and emergency response.

Applications of the concept include flood risk assessment, urban and regional planning, infrastructure design, and emergency management. By outlining the area affected by floods, veelevik supports decisions about evacuation routes, land-use zoning, and resource allocation, as well as the evaluation of flood defenses and mitigation strategies.

See also: flood extent, inundation mapping, hydrological modeling.