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Artificial drainage systems affect all components of the water and matter balance. For the proper
simulation of water and solute fluxes, information is needed about artificial drainage discharge rates
and their response times. However, there is relatively little information available about the response of
artificial drainage systems to precipitation. To address this need, we analysed 11 datasets from artificial
drainage study sites (daily or hourly resolution), one daily dataset from an open ditch system, and three
datasets from rainfall simulations on tile-drained fields.
When we considered all 11 artificial drainage study sites, we found that artificial drainage discharge
responded to 70% of all rainfall events during the year, and that the response rate differed significantly
between 56% summer and 84% in winter. A median of 23% of the yearly precipitation rate is discharged
by artificial drainage systems, varying from 9% of the precipitation in summer to 54% of the precipitation
in winter. The artificial drainage systems usually started to respond within the first hour under
rain fed conditions, and the response time increased at lower rainfall intensities ( < 1 mm h–1). The
peak outflow normally occurred within the first two days. The influence of soil texture and land use on
artificial drainage discharge rates could not be reproduced properly, due to the spatial high variability
caused by other site-specific properties.
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