Figure Legends
Figure 1: Site locations along the South Platte River in the Denver metropolitan area.
Figure 2: South Platte Watershed
Figure 3: South Platte River mean daily discharge (1995-2019), Denver, CO.
Figure 4: Biochemical oxygen demand (BOD)- Scatterplot vs distance downstream from site 1 (at 0 km), with a loess curve for each month and (black) for all months (top). Hovmöller plots showing a spatio-temporal (weighted) moving average of BOD with hot spots shown as ellipses (bottom).
Figure 5: Dissolved oxygen (DO)- Scatterplot vs distance downstream from site 1 (at 0 km), with a loess curve for each month and (black) for all months (top). Hovmöller plots showing a spatio-temporal (weighted) moving average of DO with cold spots shown as ellipses (bottom).
Figure 6: Ammonia-N- Scatterplot vs distance downstream from site 1 (at 0 km), with a loess curve for each month and (black) for all months (top). Hovmöller plots showing a spatio-temporal (weighted) moving average of NH3-N with hot spots shown as ellipses (bottom).
Figure 7: Nitrate-N- Scatterplot vs distance downstream from site 1 (at 0 km), with a loess curve for each month and (black) for all months (top). Hovmöller plots showing a spatio-temporal (weighted) moving average of NO3-N with hot spots shown as ellipses (bottom).
Figure 8: Orthophosphate- Scatterplot vs distance downstream from site 1 (at 0 km), with a loess curve for each month and (black) for all months (top). Hovmöller plots showing a spatio-temporal (weighted) moving average of orthophosphate with hot spots shown as ellipses (bottom).
Figure 9: Water Temperature- Scatterplot vs distance downstream from site 1 (at 0 km), with a loess curve for each month and (black) for all months (top). Hovmöller plots showing a spatio-temporal (weighted) moving average of temperature with hot spots shown as ellipses (bottom).
Figure 10: pH- Scatterplot vs distance downstream from site 1 (at 0 km), with a loess curve for each month and (black) for all months (top). Hovmöller plots showing a spatio-temporal (weighted) moving average of pH. No hot spots were detected.
Figure 11: Three hotspot areas
Figure 12: Hotspot 1. Nitrate-N reached its highest concentrations at the 14 km site and remained high through the 19 km site.
Figure 13: Hotspot 2. The area from 28 km – 37 km had high BOD as well as elevated concentrations of ammonia-N, nitrate-N, and orthophosphate.
Figure 14- Hotspot 3. The area from 47 km – 48 km had elevated BOD, elevated ammonia-N, elevated orthophosphate, and reduced DO.