WRAP RMC Phase II Wind Blown Dust Project Results & Status

1. WRAP RMC Phase II Wind Blown Dust ProjectResults & Status ENVIRON International Corporation and University of California, Riverside Dust Emission Joint Forum Meeting Las Vegas, NV November 16, 2004

2. Phase II Project Overview • Develop improved general methodology based on Phase I recommendations and recent literature review • Update gridded PM inventory of WB Dust for 2002 using the Inter-RPO regional modeling domain • Develop of surface friction velocities and threshold friction velocities • Develop improved emission flux relationships • Improve vacant land characterization • Disturbance • Land use type • Reservoirs • Conduct model performance evaluation

3. General Formulation for Emissions Estimation • Dust = f(LULC,z0,u*,u*th,SC) • u* = f(u,z0) • u*th = f(z0) • z0 = f(LULC)

4. Threshold Friction Velocities • u*th determined from relations developed by Marticorena, et al, (1997)

5. Emission Rates • Depends on soil type; based on results of Alfaro and Gomes (2001)

7. NLCD Summary

8. Characteristics of Dust Categories

10. Soil Characteristics

11. Reservoir Characteristics • All soils assumed loose, undisturbed • Dust events limited to 10hrs/day • Sensitivity simulations conducted based on above assumptions • Rain events: Dust re-initiated after set number of days dependent on soil texture, amount of rainfall and season

12. Rainfall > 2 inches Rainfall < 2 inches Soil type Soil type Spring/Fall Spring/Fall Summer Summer Winter Winter Sand Sand 3 1 2.1 0.7 4.2 1.4 Sandy Loam Sandy Loam 1 3 0.7 2.1 1.4 4.2 Fine Sand Loam Fine Sand Loam 1 3 2.1 0.7 4.2 1.4 Loam Loam 4 2 1.4 2.9 3.8 2.8 Silt Loam Silt Loam 4 2 1.4 2.9 2.8 3.8 Sandy Clay Loam Sandy Clay Loam 2 4 1.4 2.9 3.8 2.8 Clay Loam Clay Loam 5 3 2 3.6 7.2 4 Silty Clay Loam Silty Clay Loam 4 6 2.8 4.3 5.6 8.6 Clay Clay 7 5 3.6 5 10 7.2 Number of days after rain event to re-initiate wind erosion

13. Model Sensitivity Simulations • Run a : • No limitation on dust event duration • All soils considered loose undisturbed • Run b : • Dust events limited to 10 hrs/day • All soils considered loose undisturbed

14. Model Sensitivity Simulations • Run c : • No limitation on dust event duration • Assume 10% of barren, grass & shrublands area is disturbed • Threshold velocity for grass & shrublands = 0.5 * undisturbed value • Threshold velocity for barren lands = .27 * undisturbed value • Run d : • Dust events limited to 10 hrs/day for undisturbed soils • Assume 10% of barren, grass & shrublands area is disturbed • Threshold velocity for grass & shrublands = 0.5 * undisturbed value • Threshold velocity for barren lands = .27 * undisturbed value

15. Model ResultsScenario a: no limit on duration; all soils loose, undisturbed

16. Model ResultsScenario b: event duration <=10 hrs/day; all soils loose, undisturbed

17. Model ResultsScenario c: no limit on duration; assume 10% disturbed area for grass, shrub, barren lands

18. Model ResultsScenario d: event duration <= 10hrs/day for disturbed soils; assume 10% disturbed area for grass, shrub, barren lands

19. Dust Totals for WRAP Statestons/year

20. Annual PM10

21. Annual PM10

22. Comparison of Monthly Dust Emissions

23. Annual PM10 from Ag Land for WRAP States

24. Annual PM10 from Grass Land for WRAP States

25. Annual PM10 from Shrub Land for WRAP States

26. Annual PM10 from Barren Land for WRAP States

27. Scenario b Annual PM10 from All Dust Categories for WRAP States

28. Scenario d Annual PM10 from All Dust Categories for WRAP States

29. 2002 Annual PMC Scenario a: no limit on duration; all soils loose, undisturbed

30. 2002 Annual PMCScenario b: event duration <=10 hrs/day; all soils loose, undisturbed

31. 2002 Annual PMC Scenario c: no limit on duration; assume 10% disturbed area for grass, shrub, barren lands

32. 2002 Annual PMC Scenario d: event duration <=10 hrs/day; assume 10% disturbed area for grass, shrub, barren lands

33. 2002 Annual PMCScenario b: event duration <=10 hrs/day; all soils loose, undisturbed

34. 2002 Seasonal PMC

35. Model Limitations • Grid resolution • Coarse resolution of met data can’t resolve high wind events; wind gusts • LULC and Soils data • LULC not detailed enough on a regional-scale • Soils data lacks depth of layers, moisture data • Agricultural land adjustments • No agricultural data for Eastern states (prepared for WRAP & CENRAP regions only) • Data gaps in Ag Census

36. Model Performance Evaluation • Evaluate model results for reasonableness and accuracy • Compare predicted WB dust emissions near IMPROVE monitors with measured IMPROVE dust extinction (Bdust) • Enhancements to CMAQ to track WB and other dust • Evaluate model CMAQ model performance with and without WB dust emissions • Refined model performance evaluation using results of Etyemezian, et al. • For events characterized as wind blown dust events, determine whether dust model predicts impacts

37. 2002 Coarse Mass

38. Seasonal Coarse Mass (2002)

39. Annual Fine & Coarse Mass (2003)

40. Model Performance Evaluation (1) • Evaluate model results for reasonableness and accuracy • Compare predicted WB dust emissions near IMPROVE monitors with measured IMPROVE dust extinction (Bdust) • Identify occurrences of: • Zero WB dust and near-zero Bdust • Enhanced WB dust and near-zero Bdust • No WB dust and elevated Bdust • Enhanced WB dust and elevated Bdust • Modeled dust averaged over 5 x 5 block of grid cells centered on IMPROVE sites • Daily averaged model results paired (in time & space) with monitored data • Compare modeled PM with Bextdust • Bextdust = [FS] + 0.6[CM]

41. Model Performance Evaluation (1)

42. Model Performance Evaluation (1)

43. Model Performance Evaluation (1)

44. Model Performance Evaluation (1)

45. Model Performance Evaluation (1)

46. Model Performance Evaluation (1)

47. Model Performance Evaluation (1)

48. Model Performance Evaluation (1)

49. Model Performance Evaluation (1)

50. Model Performance Evaluation (2) • Enhancements to CMAQ to track WB and other dust emissions separately • Run CMAQ w/ and w/o WB Dust emissions • Evaluate CMAQ model results with and with out WB dust emissions