Zoeken
Zoeken kan via de modus 'eenvoudig zoeken' (één veld) of uitgebreid via 'geavanceerd zoeken' (meerdere velden). Zo kan je bv. zoeken op een combinatie van een auteursnaam (auteur), een jaartal (jaar) en een documenttype.
Boekenmand
Nuttige resultaten kan je aanvinken en toevoegen aan een mandje. De inhoud hiervan kan je exporteren of afdrukken (naar bv. PDF).
RSS
Op de hoogte blijven van nieuw toegevoegde publicaties binnen uw interessegebied? Dit kan door een RSS-feed (?) te maken van jouw zoekopdracht.
nieuwe zoekopdracht
Tracing Nitrate-Nitrogen Sources and Modifications in a Stream Impacted by Various Land Uses, South Portugal
Yevenes, M.A.; Soetaert, K.; Mannaerts, C.M. (2016). Tracing Nitrate-Nitrogen Sources and Modifications in a Stream Impacted by Various Land Uses, South Portugal. Water 8(9): 385. dx.doi.org/10.3390/w8090385
In: Water. MDPI: Basel. ISSN 2073-4441; e-ISSN 2073-4441, meer
|   |
| Author keywords |
nitrate-nitrogen; stable isotopes; streams; reactive transport model |
| Auteurs | | Top |
- Yevenes, M.A.
- Soetaert, K.
- Mannaerts, C.M.
|
|
|
| Abstract |
The identification of nitrate-nitrogen (NO3–N) origin is important in the control of surfaceand ground water quality. These are the main sources of available drinking water. Stable isotopes(15N and 18O) for NO3–N and along with a 1-D reactive transport model were used to study the originand processes that lead to nitrogen transformation and loss in a major stream that flows into a reservoirwithin an intensively cultivated catchment area (352 km2) in Alentejo-Portugal. Seasonal watersamples (October–November 2008, March 2009 and September 2009) of stream surface water, wellsand sediment pore water were collected. The results showed consistently increasing isotope valuesand decreasing NO3–N concentrations downstream. During winter (wet period, November 2008 andMarch 2009) slightly higher NO3–N concentrations were found in comparison to early fall (dry period:October 2008) and summer (dry period: September 2009). Isotopic composition of 15N and 18O valuesin surface water samples from the stream and wells indicated that the dominant NO3–N sources werederived mainly from the soil and fertilizers. There was also significant nitrification in surface water atthe head of the stream. Sediment pore waters showed high NO3–N values near the sediment-waterinterface (reaching 25 mg?N?L?1) and NO3–N concentrations sharply decreasing with sedimentdepth, suggesting significant NO3–N consumption. Denitrification was also detected using the 15Nsignature in upstream waters, but not downstream where very low NO3–N levels were measured.In the stream, the calculated isotopic enrichment factor for NO3–N was ?2.9‰for 15N and ?1.78 for18O, this indicates that denitrification accounts for 7.8% to 48% of nitrate removal. |
IMIS is ontwikkeld en wordt gehost door het VLIZ.
