English Abstract In the Netherlands situation not enough data is
available to compose a detailed representation of the contents of nitrogen
(N), potassium (K) and phosphor (P) compounds in (small) surface water. The
concentrations have to be estimated by considering the different loads of
the contributing water flows to small surface water. The relevant
components of surface water recharge are surface runoff, interflow,
including tile drainage and base flow. For the various landscapes of the
Netherlands the varying contributions of these water discharge components
have been determined. It turns out that in the Netherlands situation the
base flow is very important. the age of the base flow varies from a few to
several hundreds of years, depending on the hydrogeological situation. The
loads of the various discharge components with regard to N, P and K have
been estimated, taking into account historical situations average
concentration in surface water, where a summer and a winter situation have
to be distinguished. The results have been compared to actual measurements
in small surface water ; in general a satisfactory agreement was reached as
to nitrogen and to a lesser degree phosphor compounds. results are given in
the form of tables and figures representing small surface water for the
whole of the Netherlands. The actual (1990) situation has been treated, but
with the same method also a future (2010) situation, assuming regulating
measures with regard to fertilizer and manure application to agricultural
lands as will be imposed by the authorities.
