RT Journal Article
SR Electronic
T1 Variability of nitrate-nitrogen load estimation results will make quantifying load reduction strategies difficult in Iowa
JF Journal of Soil and Water Conservation
FD Soil and Water Conservation Society
SP 317
OP 325
DO 10.2489/jswc.72.4.317
VO 72
IS 4
A1 K.E. Schilling
A1 C.S. Jones
A1 C.F. Wolter
A1 X. Liang
A1 Y.-K. Zhang
A1 A. Seeman
A1 T. Isenhart
A1 D. Schnoebelen
A1 M. Skopec
YR 2017
UL http://www.jswconline.org/content/72/4/317.abstract
AB Many states within the Upper Mississippi River Basin are developing strategies to reduce nutrient loads to rivers. Reliable load estimation methods are needed to track progress toward nutrient reduction goals. We evaluated the variability of commonly used interpolation and extrapolation models to estimate nitrate-nitrogen (NO3-N) loads in 11 Iowa rivers. Results showed that the overall consistency between models of annual mean daily loads was low. Differences among the methods were particularly pronounced in May when the greatest NO3-N loads normally occur. The disparity in N load estimation among different methods is troubling given that states, federal agencies, or interest groups must have confidence in NO3-N load estimation procedures if the public is to believe that the load reductions strategies are working.