Interpretation of concentration‐discharge patterns in acid‐neutralizing capacity during storm flow in three small, forested catchments in Shenandoah National Park, Virginia

摘要: [1] Episodic concentration-discharge (c-Q) plots are a popular tool for interpreting the hydrochemical response of small, forested catchments. Application method involves assuming an underlying conceptual model runoff processes and comparing observed c-Q looping patterns with those predicted by model. We analyzed interpreted acid-neutralizing capacity (ANC) 133 storms collected over 7-year period from three catchments in Shenandoah National Park, Virginia. Because their lithologies represent gradient both hydrologic geochemical behavior, ranging flashy, acidic, poorly buffered catchment to moderate, neutral, well-buffered catchment. The relative frequency anticlockwise loops each decreased along this gradient. Discriminant function analysis indicated that prestorm base flow ANC was important predictor loop rotation direction; however, strength predictive relationship same trends were consistent several equally plausible three-component mixing models. Uncertainty regarding end-member timing volume possible time variation concentrations key factors precluding identification unique inconclusive results obtained on large data set suggest mechanisms basis small number without additional supporting evidence is likely be misleading.