Presented at the North Dakota GIS Hub Users Conference, September 19-20, 2017, Bismarck, ND

1. Hydrology in the GIS Age
(Eliminating the Black from Black Magic)
Thomas Johnson, PE, CFM
ND GIS Users Conference
September 20, 2017

2. Roadmap – GIS Support of Hydrolgic Methods
USGS Regression (Watershed Geometry)
NRCS Curve Number (Watershed Average, Psudo-Physical)
2-Dimensional (Varied in Space)
2-Dimensional (Rainfall Varied in Space and Time)

3. Roadmap – GIS Support of Hydrolgic Methods
USGS Regression (Watershed Geometry)
NRCS Curve Number (Watershed Average, Psudo-Physical)
2-Dimensional (Varied in Space)
2-Dimensional (Rainfall Varied in Space and Time)

4. Good Old Days

5. USGS Regional Regression
log Q50% = -0.137 + 0.510 x log (DRNAREA) + 0.630 x log (RUGGED) - 0.139 x COMPRAT
log Q20% = 0.432 + 0.513 x log (DRNAREA) + 0.632 x log (RUGGED) - 0.202 x COMPRAT
log Q10% = 0.660 + 0.511 x log (DRNAREA) + 0.636 x log (RUGGED) - 0.222 x COMPRAT
log Q4% = 0.872 + 0.510 x log (DRNAREA) + 0.640 x log (RUGGED) - 0.238 x COMPRAT
log Q2% = 0.994 + 0.509 x log (DRNAREA) + 0.641 x log (RUGGED) - 0.246 x COMPRAT
log Q1% = 1.098 + 0.509 x log (DRNAREA) + 0.641 x log (RUGGED) - 0.253 x COMPRAT
log Q0.2% = 1.284 + 0.508 x log (DRNAREA) + 0.641 x log (RUGGED) - 0.266 x COMPRAT
Where
RUGGED = STREAMLENTH * (ELEVMAX-MINBELEV)/ DRNAREA
COMPRAT = BASINPERIM / (2 * sqrt (pi * DRNAREA))

6. USGS Regional Regression
log Q50% = -0.137 + 0.510 x log (DRNAREA) + 0.630 x log (RUGGED) - 0.139 x COMPRAT
log Q20% = 0.432 + 0.513 x log (DRNAREA) + 0.632 x log (RUGGED) - 0.202 x COMPRAT
log Q10% = 0.660 + 0.511 x log (DRNAREA) + 0.636 x log (RUGGED) - 0.222 x COMPRAT
log Q4% = 0.872 + 0.510 x log (DRNAREA) + 0.640 x log (RUGGED) - 0.238 x COMPRAT
log Q2% = 0.994 + 0.509 x log (DRNAREA) + 0.641 x log (RUGGED) - 0.246 x COMPRAT
log Q1% = 1.098 + 0.509 x log (DRNAREA) + 0.641 x log (RUGGED) - 0.253 x COMPRAT
log Q0.2% = 1.284 + 0.508 x log (DRNAREA) + 0.641 x log (RUGGED) - 0.266 x COMPRAT
Where
RUGGED = STREAMLENTH * (ELEVMAX-MINBELEV)/ DRNAREA
COMPRAT = BASINPERIM / (2 * sqrt (pi * DRNAREA))

7. USGS Regional Regression
log Q50% = -0.137 + 0.510 x log (DRNAREA) + 0.630 x log (RUGGED) - 0.139 x COMPRAT
log Q20% = 0.432 + 0.513 x log (DRNAREA) + 0.632 x log (RUGGED) - 0.202 x COMPRAT
log Q10% = 0.660 + 0.511 x log (DRNAREA) + 0.636 x log (RUGGED) - 0.222 x COMPRAT
log Q4% = 0.872 + 0.510 x log (DRNAREA) + 0.640 x log (RUGGED) - 0.238 x COMPRAT
log Q2% = 0.994 + 0.509 x log (DRNAREA) + 0.641 x log (RUGGED) - 0.246 x COMPRAT
log Q1% = 1.098 + 0.509 x log (DRNAREA) + 0.641 x log (RUGGED) - 0.253 x COMPRAT
log Q0.2% = 1.284 + 0.508 x log (DRNAREA) + 0.641 x log (RUGGED) - 0.266 x COMPRAT
Where
RUGGED = STREAMLENTH * (ELEVMAX-MINBELEV)/ DRNAREA
COMPRAT = BASINPERIM / (2 * sqrt (pi * DRNAREA))
Williams County Lidar

8. USGS Regional Regression

9. USGS Regional Regression

10. USGS Regional Regression

11. Roadmap – GIS Support of Hydrolgic Methods
USGS Regression (Watershed Geometry)
NRCS Curve Number (Watershed Average, Psudo-Physical)
2-Dimensional (Varied in Space)
2-Dimensional (Rainfall Varied in Space and Time)

12. NRCS Curve
Number
Methodology
Based on Land Cover
and Soil Type

13. NRCS Curve
Number
Methodology
Based on Land Cover
and Soil Type

14. NRCS Curve
Number
Methodology
Based on Land Cover
and Soil Type

15. NRCS Curve
Number
Methodology

16. NRCS Curve
Number
Methodology
Hydrologic Soil Group
https://websoilsurvey.sc.egov.usda.gov/app/HomePage.htm

17. NRCS Curve
Number
Methodology
Land Cover

18. NRCS Curve
Number
Methodology
Intersect HSG and Land Cover
Determine Curve Number for each HSG/Land Cover
Convert to Raster

19. NRCS Curve
Number
Methodology
Use Terrain to
Delineate Subbasins
City of Minot 2015 LiDAR

20. NRCS Curve
Number
Methodology
Overlay Subbasins

21. NRCS Curve Number Methodology

22. NRCS Curve Number Methodology

23. Why Does Bismarck Break Out Impervious Area?
NRCS curve number methodology
Curve Number Runoff (inches) Area Volume
98 1.88 1-acre 6,840 cu ft
61 0.10 1-acre 347 cu ft
79.5 0.60 2-acres 4,422 cu ft

24. Roadmap – GIS Support of Hydrolgic Methods
USGS Regression (Watershed Geometry)
NRCS Curve Number (Watershed Average, Psudo-Physical)
2-Dimensional (Varied in Space)
2-Dimensional (Rainfall Varied in Space and Time)

25. 2-Dimensional Modeling

26. 2-Dimensional Modeling
National Elevation Dataset
https://nationalmap.gov/elevation.html

27. 2-Dimensional
Modeling
LANDCLASS GAP 2010

28. 2-Dimensional
Modeling

29. 2-Dimensional
Modeling
https://websoilsurvey.sc.egov.usda.gov/app/HomePage.htm

30. 2-Dimensional Modeling

32. Roadmap – GIS Support of Hydrolgic Methods
USGS Regression (Watershed Geometry)
NRCS Curve Number (Watershed Average, Psudo-Physical)
2-Dimensional (Varied in Space)
2-Dimensional (Rainfall Varied in Space and Time)

33. Use of NEXRAD – June 4, 2014 Rainfall
NEXRAD DATA

34. Temporal Variation
NDSU Ag Station
Storm Total = 2.2-inches (>10-year, 3 hr storm)
Peak Intensity = 1.05-in/hr (>2 year intensity)
NEXRAD
Storm Total = 1.8-inches (>10-year, 1-hr storm)
Peak Intensity = 3.5 in/hr = 0.31 inches in 5 min (<2 year intensity)

35. 18th Avenue Southeast – June 4, 2014

36. June 4, 2014 Rainfall Event (~1.8”)
Edison
School
Our
Lady of
Grace
Marketplace
Foods
18th Ave SW
Road
Inundation
Road
InundationDeep
Ponding
Watershed
Boundary
20-Inch Max.
Depth at Gutter
Bypass Flows
To Broadway18th Ave SW
Broadway

37. Future

38. Future

39. Questions?

40. Automated subbasins

41. Automated subbasins

42. Automated Subbasins

43. NRCS Curve
Number
Methodology
Terrain
City of Minot 2015 LiDAR

44. Celebration