Variation of nitrates in runoff from mountain and rural areas

The paper presents results of temporal and spatial variation of nitrates in streamwater in the small mountain catchment of the Jalovecký creek, the Western Tatra Mountains, Slovakia. Water samples were collected between October 2003 and April 2005 in areas with contrasting catchments. Water samples collected at the outlet of the mountain part (almost no human activities) had lower concentrations of nitrates than the samples collected donwstream in the rural area. The differences were smaller during the warm period of the year. The highest concentrations of nitrates and the highest differences among the uninhabited and inhabited areas were observed at the time of snowmelt. Samples collected along the creek in March and April 2005 showed increasing concentrations with increasing urbanization. Concentrations of nitrates measured during springs 1992, 2004 and 2005 were in similar range. Higher frequency sampling during the summer rainfall-runoff event indicated that concentrations of nitrates in the creek varied during the event. Water samples from snow had low concentrations of nitrates.