| Abstract: | Episodic concentration-discharge (c-Q) plots are a popular tool for interpreting the hydrochemical response of small, forested catchments. Application of the method involves assuming an underlying conceptual model of runoff processes and comparing observed c-Q looping patterns with those predicted by the model. We analyzed and interpreted c-Q plots of acid-neutralizing capacity (ANC) for 133 storms collected over a 7-year period from three catchments in Shenandoah National Park, Virginia. Because of their underlying lithologies the catchments represent a gradient in both hydrologic and geochemical behavior, ranging from a flashy, acidic, poorly buffered catchment to a moderate, neutral, well-buffered catchment. The relative frequency of observed anticlockwise c-Q loops in each catchment decreased along this gradient. Discriminant function analysis indicated that prestorm base flow ANC was an important predictor of loop rotation direction; however, the strength of the predictive relationship decreased along the same gradient. The trends were consistent with several equally plausible three-component mixing models. Uncertainty regarding end-member timing and relative volume and possible time variation in end-member concentrations were key factors precluding identification of a unique model. The inconclusive results obtained on this large data set suggest that identification of underlying runoff mechanisms on the basis of a small number of c-Q plots without additional supporting evidence is likely to be misleading. |
| Genre: | Article |
| ProdID: | 70027275 |
| Citation Author: | Rice, K. C.; Chanat, J. G.; Hornberger, G. M.; Webb, J. R. |
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| Citation Issue: | 5 |
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| Citation Language: | English |
| Citation Larger Work Title: | Water Resources Research |
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| Citation Search Results Text: | Interpretation of concentration-discharge patterns in acid-neutralizing capacity during storm flow in three small, forested catchments in Shenandoah National Park, Virginia; 2004; Article; Journal; Water Resources Research; Rice, K. C.; Chanat, J. G.; Hornberger, G. M.; Webb, J. R. |
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| Citation Volume: | 40 |
| Citation Year: | 2004 |
| Type: | citation/reference |
| Text: | Interpretation of concentration-discharge patterns in acid-neutralizing capacity during storm flow in three small, forested catchments in Shenandoah National Park, Virginia; 2004; Article; Journal; Water Resources Research; Rice, K. C.; Chanat, J. G.; Hornberger, G. M.; Webb, J. R. |
| URL (THUMBNAIL): | http://pubs.er.usgs.gov/thumbnails/outside_thumb.jpg |
| Date Other: | Thu, 1 Jan 2004 00:00 -0600 |
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