Load estimator (LOADEST): a FORTRAN program for estimating constituent loads in streams and rivers

Runkel, Robert L.; Crawford, Charles G.; Cohn, Timothy A.

doi:10.3133/tm4a5

Cited by 628 publications

(595 citation statements)

References 16 publications

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“…Fluvial load estimates were calculated using the S-LOADEST program written for S-Plus software (David Lorenz, USGS, written communication, 2005), which is an adaptation of LOADEST (10). Through exploratory data analysis, we determined that a commonly used model (eq 1) relating logtransformed concentrations to streamflow and seasonal terms was suitable at the study sites:…”

Section: Experimental Designmentioning

confidence: 99%

Mercury Cycling in Stream Ecosystems. 1. Water Column Chemistry and Transport

Brigham

Wentz

Aiken

et al. 2009

Environ. Sci. Technol.

226

267

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We studied total mercury (THg) and methylmercury (MeHg) in eight streams, located in Oregon, Wisconsin, and Florida, that span large ranges in climate, landscape characteristics, atmospheric Hg deposition, and water chemistry. While atmospheric deposition was the source of Hg at each site, basin characteristics appeared to mediate this source by providing controls on methylation and fluvial THg and MeHg transport. Instantaneous concentrations of filtered total mercury (FTHg) and filtered methylmercury (FMeHg) exhibited strong positive correlations with both dissolved organic carbon (DOC) concentrations and streamflow for most streams, whereas mean FTHg and FMeHg concentrations were correlated with wetland density of the basins. For all streams combined, whole water concentrations (sum of filtered and particulate forms) of THg and MeHg correlated strongly with DOC and suspended sediment concentrations in the water column.

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Section: Experimental Designmentioning

confidence: 99%

Mercury Cycling in Stream Ecosystems. 1. Water Column Chemistry and Transport

Brigham

Wentz

Aiken

et al. 2009

Environ. Sci. Technol.

226

267

View full text Add to dashboard Cite

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“…LOADEST uses time-series river water discharge data and constituent concentration to calibrate a regression model that describes long-term temporal change of constituent load in terms of various functions of discharge and time (Runkel et al, 2004;Duan et al, 2013;Chen et al, 2015):…”

Section: The Loadest Modelmentioning

confidence: 99%

“…In this study, the unknown parameters (i.e., β 0 …β 6 ) were optimized by Akaike information criterion and Schwarz criteria (Duan et al, 2013;Huang et al, 2014) for various LOADEST formats using EViews software (version 6, Quantitative Micro Software Inc., Irvine, CA, USA). Among the various formats of LOADEST regressions (Runkel et al, 2004), Eq. (2) provided the best Akaike information criterion and Schwarz criterion (Duan et al, 2013).…”

Section: The Loadest Modelmentioning

confidence: 99%

“…Additional field studies are required for developing quantitative relationships between influencing factors and phosphorus remobilization, which can be applied to modify many current models. In contrast to conventional LAM applications, this study further adopted a LOADEST model that requires minimal river monitoring data for estimating monthly and annual riverine nutrient loads over a long-term time series (Runkel et al, 2004;Duan et al, 2013;Chen et al, 2015). This approach offers an effective tool for verifying LAM results for watersheds where long-term records on nutrient sources and land use, as well as export coefficients, are unavailable for applying to lumped models.…”

Section: Model Comparisons and Implicationsmentioning

confidence: 99%

“…To deal with the challenges and limitations for conventional LAM applications, this study: (1) addresses the instream retention/remobilization P load from PS during the low flow regime based on the TP:chloride ratio to calibrate the LAM apportioned PS and NPS P inputs; and (2) employs a regression model, Load Estimator (LOADEST, Runkel et al, 2004), that can estimate long-term change in riverine nutrient loads as functions of water discharge and time to verify the LAM results. To conform to the LAM assumption that changes in PS and NPS pollution are primarily regulated by hydrological conditions, the 31-yr record was statistically divided into 5 time periods according to changing trends in flow-adjusted TP and chloride concentrations for separate calibration the LAM.…”

Section: Introductionmentioning

confidence: 99%

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Reconstructing historical changes in phosphorus inputs to rivers from point and nonpoint sources in a rapidly developing watershed in eastern China, 1980–2010

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Guo

et al. 2015

Science of The Total Environment

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Sediment and carbon fluxes along a longitudinal gradient in the lower Tana River (Kenya)

et al. 2014

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We estimated annual fluxes of suspended matter and different carbon (C) pools at three sites along the lower Tana River (Kenya), based on monthly sampling between January 2009 and December 2011. Concentrations of total suspended matter (TSM), particulate organic carbon (POC), dissolved organic carbon (DOC), and dissolved inorganic carbon (DIC) were monitored, as was the stable isotope composition of the carbon pools. Both TSM and POC concentrations showed strong seasonality, varying over several orders of magnitude, while DOC and DIC concentrations showed no seasonal variations. A strong shift in the origin of POC was observed, which was dominated by C3-derived C during dry conditions (low δ 13 C POC between À28‰ and À25‰), but had significant C4 contributions during high-flow events (δ 13 C POC up to À19.5‰). Between Garissa and the most downstream sampling point, a clear decrease in suspended matter and organic C fluxes was observed, being most pronounced during high-discharge conditions: on an annual basis, fluxes of TSM, POC, and DIC decreased by 34% to 65% for the 3 year study period. Our results suggest that floodplains along the lower Tana River could play an important role in regulating the transport of suspended matter and organic C. A comparison of current flux estimates with data collected prior to the construction of several hydropower dams reveals that the sediment loading is reduced during low discharge conditions.

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Load estimator (LOADEST): a FORTRAN program for estimating constituent loads in streams and rivers

Cited by 628 publications

References 16 publications

Mercury Cycling in Stream Ecosystems. 1. Water Column Chemistry and Transport

Mercury Cycling in Stream Ecosystems. 1. Water Column Chemistry and Transport

Reconstructing historical changes in phosphorus inputs to rivers from point and nonpoint sources in a rapidly developing watershed in eastern China, 1980–2010

Sediment and carbon fluxes along a longitudinal gradient in the lower Tana River (Kenya)

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