Loading...
Bronnen en bronbeken van Zuid-Limburg; De kwaliteit van grondwater, bronwater en beekwater
Citations
Altmetric:
Series / Report no.
Open Access
Type
Report
Language
nl
Date
2004-12-23
Research Projects
Organizational Units
Journal Issue
Title
Bronnen en bronbeken van Zuid-Limburg; De kwaliteit
van grondwater, bronwater en beekwater
Translated Title
Springs and small streams in Southern-Limburg;
Quality of groundwater, spring water and streams
Published in
Abstract
Het doel van het onderzoek aan bronnen in Zuid-Limburg
was de waterkwaliteit te bepalen als gevolg van de belasting aan maaiveld
door landbouw en atmosferische depositie. De bronnen voeren grondwater af.
Nutrienten in water bepalen mede de ecologische toestand die voor het
waterbeheer van belang is. In meerderheid zijn de nitraatconcentraties in
grond- en bronwater hoger dan 50 mg/l en afhankelijk van reistijden in de
bodem. In Zuid-Limburg zijn eenmalig 79 bronnen en 12 bronbeken onderzocht
in najaar 2001. Het onderzoek omvatte veldmetingen en laboratoriumanalyses
van de hoofcomponenten, van 49 spoorelementen en van de isotopen 3H en 18O.
Uit een onderlinge vergelijking bleek dat sommige bepalingen minder
betrouwbaar waren, zodat ze ingrijpend moesten worden bewerkt. De
concentraties in bronwater hangen samen met een veranderende belasting aan
maaiveld en reistijden van het water in de bodem, die zijn bepaald met
tritium. Limburgse lossgronden blijken een met zandgronden vergelijkbare
uitspoeling van nitraat te hebben. Denitrificatie in de diepere bodem is
van weinig betekenis. Voor veel spoorelementen komen de concentraties
overeen met de basiswaarden voor zoet grondwater. De bodem draagt praktisch
niet bij aan de concentraties. De concentraties van ammonium- en fosfaat
zijn relatief laag in het bronwater. De resultaten zijn vergeleken met
eerder onderzoek. De toename van de gemiddelde concentraties van diverse
stoffen hangt samen met een toegenomen bemesting.
The southernmost part of the Netherlands consists of plateaus, covered by loamy soils and intersected by deep valleys. The streams are fed by numerous springs. The investigation documented here evaluated the relationship between spring water quality and loads at land surface, caused mainly by fertilisation and aerial deposition. Spring surveying, well suited to determining groundwater quality, was used. Investigations at 79 springs and 12 brooks consisted of field measurements and water sampling for analysing major components, 49 trace elements and the isotopes 3H and 18O. Evaluation of results showed some determinations to be not very reliable and in need of substantial adaptations. Studying concentrations in groundwater and springs involved travel times in the soil to be derived from tritium concentrations. The relationship established here enabled surficial loads to be compared with spring water concentrations. Loamy soils in Limburg show similar trends to sandy soils where nitrate is concerned. Nitrate concentrations in groundwater and springs of more than 50 mg/l occur in a majority of cases, depending on travel times in the soil. Denitrification in deeper layers was found to have a minor impact. Concentrations for many trace elements correspond to basic values derived for fresh groundwater, implying a negligible dissolution of soil minerals. Concentrations of phosphate and ammonium are relatively low. Elaboration of previous measurements supported the modelled relationship between increasing loads at land surface and spring water quality.
The southernmost part of the Netherlands consists of plateaus, covered by loamy soils and intersected by deep valleys. The streams are fed by numerous springs. The investigation documented here evaluated the relationship between spring water quality and loads at land surface, caused mainly by fertilisation and aerial deposition. Spring surveying, well suited to determining groundwater quality, was used. Investigations at 79 springs and 12 brooks consisted of field measurements and water sampling for analysing major components, 49 trace elements and the isotopes 3H and 18O. Evaluation of results showed some determinations to be not very reliable and in need of substantial adaptations. Studying concentrations in groundwater and springs involved travel times in the soil to be derived from tritium concentrations. The relationship established here enabled surficial loads to be compared with spring water concentrations. Loamy soils in Limburg show similar trends to sandy soils where nitrate is concerned. Nitrate concentrations in groundwater and springs of more than 50 mg/l occur in a majority of cases, depending on travel times in the soil. Denitrification in deeper layers was found to have a minor impact. Concentrations for many trace elements correspond to basic values derived for fresh groundwater, implying a negligible dissolution of soil minerals. Concentrations of phosphate and ammonium are relatively low. Elaboration of previous measurements supported the modelled relationship between increasing loads at land surface and spring water quality.
Description
Publisher
Rijkswaterstaat
Directie Limburg/ Universiteit Utrecht
Directie Limburg/ Universiteit Utrecht
Sponsors
VROM-DGM-BWL