Water and nutrient budgets of the Hupselse beek catchment area
Water- en nutrientenhuishouding van het stroomgebied van de Hupselse beek
26 May 2012, PDF |
138 pages |
Eertwegh GAPH van den , Meinardi CR
RIVM Report 714901005
The Hupselse beek catchment area is located in the sandy eastern part of the Netherlands. Its hydrological borders are well defined. Water, nitrogen, and phosphorus balances are calculated for the periode April 1985 to April 1994. Mean precipitation is 845 mm.a-1, actual evapotranspiration 515 mm.a-1, and discharge 330 mm.a-1. Discharge components are surface runoff (3% of total discharge), groundwater flow to tile drains (55-75%), and groundwater flow to ditches and the brook (20-40%). Roughly 40% of the water has a travel time in the soil of less than 1 year and more than 90% leaves the area within 5 years. Roughly 20% of the soil surface nitrogen load is transported by drainage, equal to 110 kg ha-1 a-1 N. The average concentration in brook discharge is 32 mg l-1. There is no trend in the nitrogen load during the period mentioned. The mean annual phosphorus load of the brook is 1 kg ha-1 a-1 P, resulting in an average concentration of 0.21 mg l-1 and corresponding to 1% of the soil surface load. The phosphorus load is decreasing with time during the period of investigation.