Isotopes to Study Nitrogen Pollution and Eutrophication of Rivers and Lakes

The project had a significant impact in the participating countries. In 7 countries it was the first time that N-isotopes were ever applied to assess impact of nitrogen pollution on water resources variability, availability and sustainability. New and young researchers have benefited from their involvement in the project (e.g. Malaysia) though Master’s and PhD theses and were introduced on the use of isotope hydrology techniques. The participants were able to publish their findings in conferences and peer-reviewed journals, which is ample evidence of the improved capability and expertise in the use of environmental isotopes to better assess impacts of nitrogen pollution on water resources variability, availability and sustainability, and which is expected to help the stakeholders adopt protective measures and sound remediation approaches. A large dataset of nitrate isotopes was introduced in GNIR database and is available to Member States. Scientifically-wise, the project offered the identification of global patterns related to nitrate isotopes, which were linked to nitrate sources and biogeochemical processes driven by climatic and meteorological factors. For example, the project showed that river waters undergo quality deterioration due to nitrogen contamination originating mainly from organic nitrogen in manure and septic wastes (46%) and less from dissolved organic matter in the soil (28%) and the application of mineral fertilizers (21%). The link between N cycling and climate was documented through a global survey, and is expected to help further investigate climate change impact on nitrogen cycle. The perception of the locals concerning the water scarcity and contamination was examined through a socio-hydrogeological survey, which indicated “Supply clean water to public” as the main objective of water management in Sri Lanka.