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Megan E Shoda

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Field spikes were prepared at 207 stream and river sites as part of the U.S. Geological Survey (USGS) National Water Quality Assessment (NAWQA) project between December, 2012, and September, 2015. At the field site, a depth-and width-integrated environmental sample was collected, and one subsample of the environmental sample was spiked with a known amount of a spike mixture. Both the spiked subsample ("spike sample") and another subsample ("environmental sample") of the original water sample were analyzed for pesticides at the USGS National Water Quality Laboratory (NWQL) by direct injection liquid chromatography with tandem mass spectrometry (LC-MS/MS), and were used to calculate the spike recovery of each analyte....
The datasets provided here are the input data used to run the Seasonal Kendall Trend (SKT) tests and Weighted Regressions on Time, Discharge, and Season (WRTDS) models. SKT tests use "annualSamplingFreqs_allSites.csv" and "wqData_screenedSitesAll.csv" which includes, for all site-parameter combinations, information on annual sampling frequencies and the screened water-quality data, respectively. The WRTDS models use "DRB.wqdata.20200521.csv", "DRB.flow.20200610.zip", and "DRB.info.20200521.csv" for calibration which includes, for all site-parameter combinations, the water-quality data, streamflow data (as separate .csv files for each site), model specifications and site information, respectively. The multisource...
The datasets provided here are the output from the Seasonal Kendall Trend (SKT) test and Weighted Regressions on Time, Discharge, and Season (WRTDS) model that characterize changes in water quality in rivers and streams across the Delaware River Basin. SKT results are compiled in "skt_out.csv" for all combinations of site, water-quality parameter, and trend period. WRTDS results are compiled in four datasets. If unspecified, generalized flow normalization (GFN) results are reported. Stationary flow normalization (SFN) results are indicated in the datasets. "wrtds_out_annResults.csv" contains the annual estimates of mean concentration and load and GFN and SFN estimates by site and parameter for the entire calibration...
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This product consists of pesticide detections and benchmark exceedances in surface waters. These are time series data representing water years 2013 - 2017 for river sites associated with the U.S. Geological Survey National Water Quality Pesticide Monitoring Program.
This data release provides water-quality trends for rivers and streams in the Delaware River Basin determined using the Weighted Regressions on Time, Discharge, and Season (WRTDS) model and the Seasonal Kendall Trend (SKT) test. Sixteen water-quality parameters were assessed, including nutrients (ammonia, nitrate, filtered orthophosphate, total nitrogen, total phosphorus, and unfiltered orthophosphate), major ions (calcium, chloride, magnesium, potassium, sodium, and sulfate), salinity indicators (total dissolved solids and specific conductance), and sediment (total suspended solids and suspended sediment concentration). The child items include the input and output data used in the modeling and testing of water-quality...
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