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Appendix A: Coeur d'Alene Watershed Analysis Methodology for Metals and Nutrients
Pages 341-360

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From page 341... ... The committee's analysis uses the statistical method known as Weighted Regressions on Time, Discharge, and Season (WRTDS; Hirsch et al., 2010) to make inferences about concentration and flux, on a daily time step, based on the types of records that are typically available in the rivers of the CDA Lake watershed (typically on the order of 250 observations for each of the key contaminants at a given monitoring location over nearly three decades) Read the entire page →
From page 342... ... . TABLE A-1 Station Codes for USGS Data Used in WRTDS Analysis Gage Location Station Code NF CDA River at Enaville 12413000 SF CDA River at Elizabeth Park 12413210 SF CDA River near Pinehurst 12413470 CDA River near Cataldo 12413500 CDA River near Harrison 12413860a St. Read the entire page →
From page 343... ... , and further information on the Kalman filter estimates is provided at the EGRET web page for WRTDSKalman.2 An illustrative example calculation is provided below for total phosphorus trends at the South Fork of the CDA River near Pinehurst (full list of parameter codes described in Table A-2) Read the entire page →
From page 344... ... 344 THE FUTURE OF WATER QUALITY IN COEUR D'ALENE LAKE Retrieve Data from USGS Web Service sta <- "12413470" param <- "00665" startDate <- "1988-10-01" endDate <- "2020-09-30" Sample <- readNWISSample(sta, param, startDate, endDate) length(Sample$Date) Read the entire page →
From page 345... ... APPENDIX A 345 Retrieve Daily Discharge Data (code "00060") Daily <- readNWISDaily(sta, "00060", startDate, endDate) Read the entire page →
From page 346... ... units ## 1 Phosphorus, water, unfiltered, milligrams per liter as phosphorus mg/l as P ## paramShortName paramNumber constitAbbrev paStart paLong ## 1 Phosphorus 00665 Phosphorus 10 12 Read the entire page →
From page 347... ... APPENDIX A 347 Create the eList and Estimate the WRTDS Model eList <- mergeReport(INFO, Daily, Sample) eList <- modelEstimation(eList) Read the entire page →
From page 348... ... 348 THE FUTURE OF WATER QUALITY IN COEUR D'ALENE LAKE FIGURE A-2 WRTDS-generated plots of total phosphorus at the South Fork of the CDA River near Pinehurst showing discharge versus concentration (top left) , concentration time series (top right) Read the entire page →
From page 349... ... APPENDIX A 349 FIGURE A-3 WRTDS-generated plots of total phosphorus at the South Fork of the CDA River near Pinehurst showing discharge versus concentration (top left) , concentration time series (top right) Read the entire page →
From page 350... ... 350 THE FUTURE OF WATER QUALITY IN COEUR D'ALENE LAKE FIGURE A-4 Additional set of statistical diagnostic plots for total phosphorus trends at the South Fork (SF) of the CDA River near Pinehurst. Read the entire page →
From page 351... ... # look at trend results and annual values # these curves make up part of figure 3-23 plotConcHist(eList, plotAnnual = FALSE, plotGenConc = TRUE) Read the entire page →
From page 352... ... plotFluxHist(eList, fluxUnit = 8, plotAnnual = FALSE, plotGenFlux = TRUE) FIGURE A-6 Total phosphorus flux as a function of water year at the South Fork of the CDA River near Pinehurst. Read the entire page →
From page 353... ... ) ## ## SF Coeur D Alene River nr Pinehurst, ID ## Phosphorus ## Water Year ## ## Concentration trends ## time span change slope change slope ## mg/L mg/L/yr % %/yr ## ## 1990 to 2000 0.0098 0.00098 30 3 ## 1990 to 2010 0.01 0.00052 32 1.6 ## 1990 to 2020 -0.0022 -7.5e-05 -6.9 -0.23 Read the entire page →
From page 354... ... ## ## SF Coeur D Alene River nr Pinehurst, ID ## Phosphorus ## Water Year ## ## Change estimates 2020 minus 1990 ## ## For concentration: total change is -0.00225 mg/L ## expressed as Percent Change is -6.9 % ## ## Concentration v. Q Trend Component -6.9 % ## Q Trend Component 0 % ## ## ## For flux: total change is 0.00205 million kg/year ## expressed as Percent Change is 17 % ## ## Concentration v. Read the entire page →
From page 355... ... Do Not Reject Ho ## best estimate of change in concentration is -0.00225 mg/L ## Lower and Upper 90% CIs -0.016482 0.006191 ## also 95% CIs -0.018901 0.008980 ## and 50% CIs -0.010393 0.000381 ## approximate two-sided p-value for Conc 0.52 ## Likelihood that Flow Normalized Concentration is trending up = 0.261 is trending down = 0.739 ## ## Should we reject Ho that Flow Normalized Flux Trend = 0 ? Do Not Reject Ho ## best estimate of change in flux is 0.00205 10^6 kg/year ## Lower and Upper 90% CIs -0.003983 0.007787 ## also 95% CIs -0.005889 0.008888 ## and 50% CIs -0.000616 0.003356 ## approximate two-sided p-value for Flux 0.69 ## Likelihood that Flow Normalized Flux is trending up = 0.654 is trending down = 0.346 ## ## Upward trend in concentration is unlikely ## Upward trend in flux is about as likely as not ## Downward trend in concentration is likely ## Downward trend in flux is about as likely as not # next we will look at trends from 2000 - 2020 year1 <- 2000 pairsOut <- runPairs(eList, year1, year2, windowSide = 0, oldSurface = TRUE) Read the entire page →
From page 356... ... Reject Ho ## best estimate of change in flux is -0.00776 10^6 kg/year ## Lower and Upper 90% CIs -0.01361 -0.00398 ## also 95% CIs -0.01481 -0.00336 ## and 50% CIs -0.01006 -0.00651 ## approximate two-sided p-value for Flux 0.01 ## * Note p-value should be considered to be < stated value ## Likelihood that Flow Normalized Flux is trending up = 0.00249 is trendin g down = 0.998 ## ## Upward trend in concentration is highly unlikely ## Upward trend in flux is highly unlikely ## Downward trend in concentration is highly likely ## Downward trend in flux is highly likely # finally we will look at trends from 2010 - 2020 year1 <- 2010 pairsOut <- runPairs(eList, year1, year2, windowSide = 0, oldSurface = TRUE) Read the entire page →
From page 357... ... Reject Ho ## best estimate of change in flux is -0.00852 10^6 kg/year ## Lower and Upper 90% CIs -0.01443 -0.00365 ## also 95% CIs -0.01520 -0.00215 ## and 50% CIs -0.01188 -0.00728 ## approximate two-sided p-value for Flux 0.01 ## * Note p-value should be considered to be < stated value ## Likelihood that Flow Normalized Flux is trending up = 0.00249 is trendin g down = 0.998 ## ## Upward trend in concentration is highly unlikely ## Upward trend in flux is highly unlikely ## Downward trend in concentration is highly likely ## Downward trend in flux is highly likely # and now we will do 90% confidence intervals on the whole time series seriesOut <- runSeries(eList, windowSide = 0, oldSurface = TRUE) Read the entire page →
From page 358... ... 358 THE FUTURE OF WATER QUALITY IN COEUR D'ALENE LAKE FIGURE A-7 Total phosphorus concentration at the South Fork of the CDA River near Pinehurst as a function of water year. Solid line shows the flow-normalized concentration, and the dotted lines show the 90 percent confidence interval. Read the entire page →
From page 359... ... , with an application to Chesapeake Bay river inputs 1. Journal of the American Water Resources Association 46(5) Read the entire page →

From page 341...

... The committee's analysis uses the statistical method known as Weighted Regressions on Time, Discharge, and Season (WRTDS; Hirsch et al., 2010) to make inferences about concentration and flux, on a daily time step, based on the types of records that are typically available in the rivers of the CDA Lake watershed (typically on the order of 250 observations for each of the key contaminants at a given monitoring location over nearly three decades)

Appendix A: Coeur d'Alene Watershed Analysis Methodology for Metals and Nutrients Pages 341-360

Appendix A: Coeur d'Alene Watershed Analysis Methodology for Metals and Nutrients
Pages 341-360