Dräneringsytan

Dräneringsytan is a term used in hydrology and civil engineering to describe the land area that contributes water to a drainage outlet, such as a tile drain or drainage ditch, under a given set of conditions. It functions as the catchment for a specific drainage outlet rather than for the entire plot or field.

The boundary of the dräneringsytan is determined by the underlying topography and the drainage network. It is typically delineated using topographic maps or digital elevation models (DEMs) and may be smaller or larger than the farm parcel depending on how groundwater and surface runoff flow toward the outlet. The concept is central to designing and assessing drainage systems, as it directly influences estimates of discharge, pipe sizing, and outlet capacity.

In practice, calculating or delineating a dräneringsytan involves considering soil properties, permeability, rainfall and evapotranspiration, groundwater levels, and the efficiency of the drainage system. The area is used to perform water balance calculations, plan drainage installation, and evaluate drainage performance for agricultural fields, peatlands, or urban drainage projects. It is related to, but distinct from, broader catchment or watershed concepts, since it focuses on the portion of land contributing to a specific drainage outlet.