RELATIONSHIPS BETWEEN MAJOR ION CHEMISTRY AND LAND USE IN THE ORISKANY CREEK, NY WATERSHED

We studied the relationship between major ion chemistry and land use in the Oriskany Creek Watershed in central New York. The 374 km² watershed is mostly rural, with forest and shallow-rooted agriculture as the main land uses. Fifty-five points in the basin were sampled once during base flow conditions and twice during runoff conditions. Sampling locations ranged from first order tributaries to the main stream, with more samples taken from small tributaries in the upper reaches of the basin. Water samples were analyzed for major ions using ion chromatography and plotted using GIS software to test for correlation between water chemistry and land use. Our results showed that nitrate concentrations were higher during base flow conditions than during runoff conditions. Total dissolved solids were generally higher during runoff conditions. Nitrate and potassium concentrations showed a positive correlation with percentage of agricultural land cover, and nitrate concentrations were negatively correlated to the percentage of forested land cover. Chloride levels appear to be correlated with increased residential and commercial land cover. Further data collection is needed in sub-basins with more diverse land cover types to test the statistical significance of these findings.