A trend-analysis of eutrophication variables was performed for a large number of lakes in The Netherlands. Data of in total 231 lakes were available. Data on chlorophyll-a, total phosphorus (total-P) and total nitrogen (total-N) were analysed over the period 1980-1996. Summer-averaged concentrations for chlorophyll-a, total-P and total-N decreased in respectively 65%, 73% and 75 of the lakes with at least eight years data between 1980 and 1996. Results for winter means were comparable (a negative trend in 54%, 77% and 69% for concentrations of chlorophyll-a, total-P and total-N respectively). Since 1980 the median decrease in the summer averaged concentrations of chlorophyll-a, total-P and total-N is 2.61 μg l−1 y−1, 0.008 mg l−1 y−1 and 0.046 mg l−1 y−1, respectively, illustrating the effects of (inter)national and regional measures to combat eutrophication.
Research Article|February 01 1998
Trend-analysis of eutrophication variables in lakes in The Netherlands
Water Sci Technol (1998) 37 (3): 235-240.
Rob Portielje, Diederik T. Van der Molen; Trend-analysis of eutrophication variables in lakes in The Netherlands. Water Sci Technol 1 February 1998; 37 (3): 235–240. doi: https://doi.org/10.2166/wst.1998.0215
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