Lower Cape Fear River Estuary Model Progress Report

Transcription

1 Lower Cape Fear River Estuary Model Progress Report Jim Bowen, UNC Charlotte August 15, 2007 Raleigh, NC

2 Description of Model Application Black River, FlowBoundary Cond. NE Cape Fear Flow Boundary Cond. Cape Fear R. Flow Boundary Cond. Lower Cape Fear River Estuary Schematic Open Boundary Elevation Cond.

3 DO Conceptual Model BOD Sources NECF & Black R. BOD Load decaying phytopl. Cape Fear BOD Load Muni & Ind. BOD Load Sediment Sediment O 2 Demand

4 DO Conceptual Model BOD Sources, DO Sources NECF & Black R. BOD Load Cape Fear BOD Load Muni & Ind. BOD Load MCFR Inflows Sediment decaying phytopl. Phytoplank. Productivity Surface Reaeration Ocean Inflows Sediment O 2 Demand

5 DO Conceptual Model Cape Fear BOD Load BOD Sources, DO Sources & Sinks NECF & Black R. BOD Load Muni & Ind. BOD Load MCFR Inflows Sediment decaying phytopl. Input of NECF & Black R. Low DO Water Surface Reaeration Phytoplank. BOD Productivity Consumption Ocean Inflows Sediment O 2 Demand

6 Modeling Developments (Hydrodynamic model) 1. Moved model boundary for NECF up to Burgaw monitoring station 2. Created flow boundary conditions for for Black and NECF using station pairs (Tomahawk and Currie, Chinquapin and Burgaw) 3. Created calibration database of all available hydrodynamic data (DWQ Ambient, LCFRP, special study, USGS)

7 More model developments (Hydro) 4. Created scripts and monitoring data files to compare long-term daily and short-term hourly hydrodynamic data 5. Created new shortwave solar radiation file using observed to replace data estimated from meteorological forcings 6. Delineated NECF watersheds in estuary to improve placement of freshwater loadings

8 1. Added new cells to extend model to Burgaw monitoring station 950 horizontal cells in old grid, 1004 cells in new grid 8 vertical layers Average cell dx = 300 m, dy = 400 m Separate cells for channel and adjoining marshes ** show grids w/google Earth

9 2. Created new Black R. and NECF R. flow boundary conditions Needed flows at model boundary for Black and NECF rivers Had two stations in each watershed for approximately one year Used lagged and scaled flows Tomahawk, Chinquapin) to estimate missing data for model boundaries

10 Flows at Burgaw High flow event from Hurricane Charlie seen Q3, 2004

11 5. Created new short-wave solar radiation file Had previously used estimated short-wave solar using met data (cloud cover, day of year) for estimation Previous data set produced overpredictions of temperature during summer Discovered a Wilmington short wave data set existed from NWS Found these data gave much improved temperature predictions

12 Example temperature time series Predicted temps near 40 deg C much higher than observations

13 6. Added new freshwater sources for NECF, Black, Cape Fear Area between Burgaw and mouth of NECF includes a signficant portion of watershed drainage area (approx. 10% of total) Need to add additional water inputs to correctly account for location of freshwater inputs Also made corrections for Black and Cape Fear Rivers (show w/ google earth) Estimated flows by scaling NECF flows at Burgaw

14 Example: 6 additional NECF sources added River Watershed I J Estimated Area (sqmi) QSER multiplier multiplier addition # NECF NECF NECF NECF NECF NECF NECF NECF NECF NECF NECF NECF NECF NECF NECF NECF NECF NECF Total N/A N/A NECF Total N/A N/A 790

15 Additional Estuary Sources: Summary River # Srcs Sq. Mi. DA% Northeast Cape Fear Cape Fear below NECF Cape Fear above Navassa Black River Total %

16 More model developments (Hydro) 7. Developed new downstream boundary elevation file NOAA measured elevations at Southport 8. Created downstream boundary salinity data using Marker 12 salinity continuous monitoring 9. Calibrated hydrodynamic model by running model w/ various bottom roughnesses and assumed bottom elevations

17 Hydrodynamic Model Results Show temperature and salinity time series comparisons Also show statistical measures of model fit to data Use all available salinty and temperature data sources (LCFRP, USGS, DWQ) Use 2003 model startup, make comparison for April - November 2004

18 April - November 2004 Temperature

19 April - November 2004 Temperature

20 April - November 2004 Temperature

21 April - November 2004 Temperature

22 April - November 2004 Temperature

23 April - November 2004 Temperature

24 April - November 2004 Temperature

25 April - November 2004 Temperature

26 April - November 2004 Temperature

27 April - November 2004 Temperature

28 April - November 2004 Temperature

29 April - November 2004 Temperature

30 April - November 2004 Temperature

31 April - November 2004 Temperature

32 April - November 2004 Temperature

33 April - November 2004 Temperature Statistical Measures of Fit (units of deg C) mean(pred-obs) = ME_norm = RMSE = MAE = MAE_norm = RMSE_norm = r_squared = num data comparisons = 4150 r 2 adjusted for bias =

34 April - November, Hourly Temperatures

35 April - November, Hourly Temperatures

36 April - November, Hourly Temperatures

37 April - November, Hourly Temperatures Fit Statistics (units are deg C) mean(pred-obs) = ME_norm = RMSE = MAE = MAE_norm = RMSE_norm = r_squared = num data comparisons = r 2 adjusted for bias =

38 April - November 2004 Salinity

39 April - November 2004 Salinity

40 April - November 2004 Salinity

41 April - November 2004 Salinity

42 April - November 2004 Salinity

43 April - November 2004 Salinity

44 April - November 2004 Salinity

45 April - November 2004 Salinity

46 April - November 2004 Salinity

47 April - November 2004 Salinity Statistical Measures of Fit (units of PSU) mean(pred-obs) = ME_norm = RMSE = MAE = MAE_norm = RMSE_norm = r_squared = num data comparisons = mse/var(obs) =

48 July 2004 Salinity, Hourly Data, Bottom

49 July 2004 Salinity, Hourly Data, Bottom

50 July 2004 Salinity, Hourly Data, Bottom

51 July 2004 Salinity, Hourly Data, Bottom

52 July 2004 Salinity, Hourly Data, Bottom Fit Statistics (salinity units) mean(pred-obs) = ME_norm = RMSE = MAE = MAE_norm = RMSE_norm = r_squared = num data comparisons = mse/var(obs) =

53 July 2004 Salinity, Hourly Data, Top

54 July 2004 Salinity, Hourly Data, Top

55 July 2004 Salinity, Hourly Data, Top

56 Hydrodynamic Calibration - Summary Calibration essentially complete Excellent agreement w/ temperature and salinity Elevation agreement (not shown) still needs some work to get predicted tidal amplitude attenuation to match observed attenuation

57 More Model Developments (Water Quality Model) 1. Reviewed long-term BOD data to determine organic matter decay rates 2. Created new point source load files w/ additional NECF sources and variable organic matter decay rates

58 Long-term BOD measurements, data sources 1. IP long-term BOD tests (BOD vs. time) 2. Wilmington long-term tests (BOD vs. time) 3. DWQ special study data (BOD30/BOD5 ratio) 4. LCFRP data (BOD20/BOD5 ration, partial data set)

59 IP and Wilmington long-term BOD measurements Multiple measurements, BOD exerted vs. time Fit data to determine ultimate BOD and BOD decay rate

60 IP Measurements, 7/20: BODU = 110 mg/l, K = 0.03 day -1 7/27: BODU = 90 mg/l, K = 0.03 day -1

61 Wilmington Measurements Wilmington NS: BODU = 32 mg/l, K = 0.05 day -1 Wilmington SS: BODU = 118 mg/l, K = 0.13 day -1

62 DWQ and LCFRP long-term BOD data Have BOD 5 + BOD20 or BOD30 data Have multiple times and locations Use ratio of BOD s to determine BOD decay rates

63 BOD exerted for 2 decay rates Ratio decreases as k increases

64 BOD30/BOD5 ratio Given BOD30/BOD5 ratio, k can be found from curve

65 LCFRP data Based on July 02 - June 03 monthly data at 3 boundary stations (NC11, B210, NCF117) = 36 measurements w/ BOD5 and BOD20 Mean = day -1 Expect to get additional data for later years

66 DWQ Special Study Data 7 stations, 2 measurements during July 2004 BOD 30 and BOD 5 measurements Use BOD30/BOD5 ratio to determine K (data not shown) Average k = 0.07 day -1 Standard deviation = 0.01 day -1

67 Long-term BOD data - summary IP WW has lowest decay rate (0.03 day -1 ) River water has intermediate decay rates ( day -1 ) Wilmington WWTP decay rates quite variable ( day -1 ) Using two DOC types, labile (k = 0.1 day) and refractory (k = 0.03 day) Most sources will have some of both labile and refractory

68 DO model results so far

69 DO model results so far

70 DO model results so far

71 DO model results so far

72 DO model results so far

73 DO model results so far

74 DO model results so far

75 DO model results so far

76 DO model results so far

77 DO model results so far

78 DO model results so far Fit statistics (units are mg/l) mean(pred-obs) = ME_norm = RMSE =1.5 MAE = MAE_norm = RMSE_norm = r_squared = num data comparisons = mse/var(obs) =

79 Upcoming Work Finish assigning decay rates and redefining loads once additional BOD data are available Work on incorporating SOD data in a more detailed way Do additional model/data comparisons w/ DWQ special study data Plan to finish water quality calibration by end of September and begin to consider how to do scenario tests