A GIS-based technique for linking landscape characteristics to non-point source nitrogen export potential: implications for contributing areas management |
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Authors: | Diana Mitsova Xinhao Wang |
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Affiliation: | 1. Florida Atlantic University, SURP , Fort Lauderdale , FL , 33301 , USA;2. University of Cincinnati , 6210 DAAP, Cincinnati , OH , 45221 , USA |
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Abstract: | A Nitrate-N Leaching Index (NLI) is calculated and the results indicate that nitrogen loss in the study area occurs through both leaching and surface runoff. A non-linear regression model of trapping efficiency was combined with a first order decay model to examine the impact of soil characteristics, slope, vegetative cover, land use and distance to streams on the spatial pattern of non-point source nitrogen inputs to streams. The model evaluates the statistical significance of each landscape factor and provides an easy interpretation of the landscape delivery ratio of nitrogen based on a pixel-based characterisation of the watershed. The model was validated by comparing the distributions of the observed and estimated monthly nitrogen concentrations. The exploratory GIS-based method presented here can improve the understanding of the impact of landscape characteristics on nitrate-nitrogen contributing areas and therefore assist watershed management efforts. |
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Keywords: | Nitrate Leaching Index non-linear regression Weibull distribution N decay coefficients Kruskal-Wallis nonparametric test |
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