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Titel |
Distributed hydrological modeling of total dissolved phosphorus transport in an agricultural landscape, part II: dissolved phosphorus transport |
VerfasserIn |
W. D. Hively, P. Gérard-Marchant, T. S. Steenhuis |
Medientyp |
Artikel
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Sprache |
Englisch
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ISSN |
1027-5606
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Digitales Dokument |
URL |
Erschienen |
In: Hydrology and Earth System Sciences ; 10, no. 2 ; Nr. 10, no. 2 (2006-04-26), S.263-276 |
Datensatznummer |
250007986
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Publikation (Nr.) |
copernicus.org/hess-10-263-2006.pdf |
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Zusammenfassung |
Reducing non-point source phosphorus (P) loss to drinking water reservoirs is
a main concern for New York City watershed planners, and modeling of P
transport can assist in the evaluation of agricultural effects on nutrient
dynamics. A spatially distributed model of total dissolved phosphorus (TDP)
loading was developed using raster maps covering a 164-ha dairy farm
watershed. Transport of TDP was calculated separately for baseflow and for
surface runoff from manure-covered and non-manure-covered areas. Soil test P,
simulated rainfall application, and land use were used to predict
concentrations of TDP in overland flow from non-manure covered areas.
Concentrations in runoff for manure-covered areas were computed from
predicted cumulative flow and elapsed time since manure application, using
field-specific manure spreading data. Baseflow TDP was calibrated from
observed concentrations using a temperature-dependent coefficient. An
additional component estimated loading associated with manure deposition on
impervious areas, such as barnyards and roadways. Daily baseflow and runoff
volumes were predicted for each 10-m cell using the Soil Moisture
Distribution and Routing Model (SMDR). For each cell, daily TDP loads were
calculated as the product of predicted runoff and estimated TDP
concentrations. Predicted loads agreed well with loads observed at the
watershed outlet when hydrology was modeled accurately (R2 79%
winter, 87% summer). Lack of fit in early spring was attributed to
difficulty in predicting snowmelt. Overall, runoff from non-manured areas
appeared to be the dominant TDP loading source factor. |
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