Fordampning fra pileanlæg med bund. En undersøgelse af vegetations- og klimaforholds indflydelse på fordampningen i spildevandsanlæg

摘要

#The actual evapotranspiration (ETA) was investigated over a year in two constructed wetland systemsfunctioning as single household wastewater systems located in Denmark. A polyethylene-lined basinfilled with soil is planted with clones of willow (Salix viminalis) grown as a short rotation coppice. Thebasin receives input from wastewater and precipitation and has no discharge but the water isevapotranspired by the willow and nutrients are consumed by the willow biomass, which is cut downregularly. Measurements of this investigation include local meteorological data, water input,fluctuating groundwater level, fluctuations in soil water storage, biomass growth, leaf areadevelopment, lysimeter weighing of the ETA of single willow trees and water loss through leaves,lenticels and kutikula of single cut willow shoots. The species Salix viminalis was effective inevapotranspiring.It was concluded that the yearly ETA of the constructed wetlands is more than twice as high aspotential evaporation calculated from Makkink. KC between 2,3-2,6 was found. The average potentialevaporation (Makkink) in Denmark is 582mmyear-1. The average precipitation in Denmark is 895mmyear-1.