Appendix 2-D(2)

Comparison of SAM Outputs to Monitoring Data from Monitoring Sites in Scioto River Basin, 

OH

This appendix, the second of three spreadsheets, is provided in support of the comparison of 

model outputs with measured data in Section 2.4 of the SAP document Development of a 

Spatial Aquatic Model (SAM) for Pesticide Assessments. As a part of the model evaluation for 

SAM, this appendix provides a comparison of estimated daily atrazine concentrations for 2000-

2014 to monitoring data from the Atrazine Ecological Exposure Monitoring Program (AEEMP), 

Atrazine Monitoring Program (AMP), and Heidelberg University's National Center for Water 

Quality Research (NCWQR) at the Scioto River. Monitoring data and descriptions can also be 

found in Appendix 2C.

The table to the right describes each tab linked to the monitoring sites found in the Scioto 

River test basin. Figures 1 and 2 (below) shows the locations of the test sites. Each basin is 

identified both by the original study ID and by the NHDplus (version 2) comid for the 

catchment that is associated with the monitoring sampling site (pour point).

Figure 1: Location of Test Basin Areas for SAM Model Development and Evaluation.
Figure 2: AEEMP and AMP Monitoring Sites in the Scioto River (OH) Test Basin Area.
Worksheet Tab Contents

SummaryByYear Summary of annual (2000-2014) total mass lost, total runoff, maximum atrazine 

concentrations and comparisons with monitoring for each test basin site. Includes 

graphs comparing estimated concentrations with monitoring data.

OH-04_3483775_basin Results for AEEMP site OH-04 (NHD+ comid 3483775)

OH-10rvr_5214753_basin Results for AMP site OH-10 river (NHD+ comid 5214753)

OH-11res_5213585_basin Results for AMP site OH-11 reservoir (NHD+ comid 5213585)

HU_SR_3486865_basin Results for Heidelberg U. NCWQR monitoring site for Scioto River (NHD+ comid 

3486865)

Monitoring Monitoring data for each of the test basin sites (used for graphs)

Each basin tab includes the following fields:

Field Description/source

Date Daily dates from scenario, 1/1/2000 - 12/31/2014

Est. Conc (ug/L) Estimated daily concentrations generated using aggregated scenarios (soils grouped 

by WQI criteria)

Rmass (kg) Daily pesticide mass flux lost in runoff generated using aggregated scenarios (soils 

grouped by WQI criteria)

Runoff(m) Daily runoff volume using aggregated scenarios (soils grouped by WQI criteria)

RConc(ug/L) Daily runoff concentration using aggregated scenarios (soils grouped by WQI criteria)

TotalFlow(m3) Total flow estimate in stream mixing cell, based on NHD+ data

baseflow(m3) Base flow estimate for stream mixing cell (see Section 2.1)

MassAppl Daily mass applied based on pesticide application rate, corn area, length of 

application window (50 days)

Cumul. Mass Appl. Cumulative mass of pesticide applied in watershed (summing MassAppl)
Cumul. Runoff Loss, Aggreg 

Scenarios

Cumulative pesticide mass lost in runoff (summing daily Rmass values)

Year Year of simulation

Mass(kg)

Sum of daily pesticide mass loss by year for soils aggregated by WQI scenarios

Runoff(m) Sum of daily runoff volumes by year for soils aggregated by WQI scenarios

Max conc

Maximum annual concentration in water for soils aggregated by WQI scenarios

Max runoff conc

Maximum annual concentration in runoff for soils aggregated by WQI scenarios

CornArea(m2) Corn area, based on watershed recipe files for 2010-2014 CDL

CornFrac

Corn as a fraction of watershed area, based on watershed recipe files for 2010-2014 

CDL

Applied(kg)

Total kg of pesticide applied by year, based on application rate, area in corn

FracLoss

Fraction of pesticide lost to runoff by year: ratio of annual mass runoff loss to amount 

applied