Original scientific paper
https://doi.org/10.21857/9e31lh4zem
COMPARATIVE ANALYSIS OF NITRATE CONCENTRATION IN UPPER AND LOWER AQUIFER OF THE VARAŽDIN SYSTEM OF AQUIFERS
Ivan Kovač
; Sveučilište u Zagrebu, Geotehnički fakultet Varaždin
Barica Kovačev-Marinčić
; Sveučilište u Zagrebu, Geotehnički fakultet Varaždin
Nikolina Novotni-Horčička
orcid.org/0000-0002-4914-5521
; Varkom d. d. Varaždin
Josip Mesec
; Sveučilište u Zagrebu, Geotehnički fakultet Varaždin
Jelena Vugrinec
; Sveučilište u Zagrebu, Geotehnički fakultet Varaždin
Abstract
Time series of annual averages of nitrate concentration in five well fields in the Counties of Varaždin and Međimurje were analised in the paper. The nitrate concentration was analised separetly in the upper and the lower aquifer of the Varaždin system of aquifers. On the basis of the time series, it was found out that the nitrate concentration is higher in the upper aquifer at the all well fields. The MAC (maximum admissible concentration) was not exceeded, except at the Varaždin well field, where the concentration has been heightened for several decades.
The statistical significance of the difference between the annual averages of the nitrate concentration in the upper and the lower aquifer was defined by t-test. The analysis was carried out for the Bartolovec well field in 2003 when the difference was the smallest during the period of monitoring. The calculated t-value was larger than the critical one. Therefore, it was concluded that the difference between the annual averages of the nitrate concentrations in the upper and the lower aquifer of the Varaždin system of aquifers is statistically significant.
Keywords
Varaždin system of aquifers; upper and downer aquifer; groundwater; nitrate concentration; time series; t-test
Hrčak ID:
191522
URI
Publication date:
29.12.2017.
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