Articles | Volume 17, issue 12
Hydrol. Earth Syst. Sci., 17, 4897–4906, 2013

Special issue: Statistical methods for hydrological applications

Hydrol. Earth Syst. Sci., 17, 4897–4906, 2013

Research article 06 Dec 2013

Research article | 06 Dec 2013

Statistical analysis to characterize transport of nutrients in groundwater near an abandoned feedlot

P. Gbolo and P. Gerla P. Gbolo and P. Gerla
  • Harold Hamm School of Geology and Geological Engineering, University of North Dakota, Grand Forks, ND, USA

Abstract. Surface water from a lagoon and groundwater samples from 17 wells within and near an abandoned feedlot in northwestern Minnesota, USA, were analyzed for carbon, nutrients, and field parameters. The feedlot is surrounded by wetlands that act as receptors of nutrients from the feedlot. Q- and R-mode multivariate analyses performed on total carbon (TC), inorganic carbon (IC), total organic carbon (TOC), nitrite-nitrogen (NO2-N), nitrate-nitrogen (NO3-N), ammonium-nitrogen (NH4-N), soluble or dissolved reactive phosphorus (DRP), and total phosphorus (TP) indicated three groups of the chemical species, which reflected variability in groundwater chemistry. Factor analysis indicated approximately 82% of the variability in factor 1 was caused by TC, IC, TOC, and DRP, while in factor 2 approximately 79% of the variability was caused by NO2-N, NO3-N, and TP. In factor 3, only NH4-N contributed 31% of the variability. Groundwater isotope and spatial distribution analysis indicated reduced nitrate concentration from the source to the wetlands, with variation in NO2-N, NO3-N, and NH4-N concentrations attributed to the plant nutrient uptake, high rate of denitrification and/or the dissimilatory nitrate reduction to ammonium. This study indicated the value of multivariate analyses in characterizing variability in groundwater quality.