标题：NITRATE CONCENTRATION CHANGES IN A RIVER AND ITS RESERVOIR WITHIN AN AGRICULTURALLY-INFLUENCED WATERSHED: THE RIVER LEDAVA (SE AUSTRIA AND NE SLOVENIA) CASE STUDY
摘要：Understanding how a reservoir responds to external nutrient loading is essential in order to assess the effects of nutrient load reduction strategies within the watershed as each reservoir is unique. As nitrate (NO3-) concentration changes in fresh waters have been used to describe biogeochemical and hydrological processes in and between terrestrial and aquatic ecosystems, we monitored nitrate (NO3-) concentrations on the river Ledava and its associated reservoir Ledavsko jezero bi-weekly between June 2013 and January 2014. The results showed the importance of continuous and simultaneous water monitoring of the river and its associated reservoir to indicate processes and parameters which influence NO3- dynamics in reservoir. Significant correlations were found between precipitation, discharge and nitrate concentrations. The prevailing influence of riverine inflow to the reservoir and the loose correlation between nitrate concentration and discharge in the reservoir indicate that river inflow is subjected to biogeochemical processes within the reservoir relative to season and hydraulic retention time as the latter increases with low flow. Through an analysis of data this study shows that nitrate concentration changes in the reservoir are strongly dependent on riverine inflow, season dependent processes and reservoir operation regime.
关键词：river; shallow reservoir; watershed; nitrate; hydrological and biogeochemical processes
