1 Integrating Water Resources Engineering and Geographic Information Systems (GIS) National Weather Service NWSRFS International Workshop October 21-23, 2003 Kansas City, Missouri

2 Introductions… David Preusch, P.E. (Manager, Water Resources, Alexandria, VA) Michael Baker Jr., Inc Eisenhower Avenue Alexandria, VA (703)

3 About Baker Founded in 1940 Employee Owned Company Two core businesses: Engineering and Energy Headquartered in Pittsburgh, PA 4,200 employees in 30+ offices around the world Consistently ranked in the top 10% of Professional Design Service Firms

4 Baker’s National Flood Hazard Analysis and Mapping Services for FEMA Engineering, hydrology & hydraulics, floodplain studies, and floodplain mapping services for FEMA since Helped develop standards and regulations for National Flood Insurance Program

5 Combining 3-D smart maps that contain hidden information about planimetric features to analyze spatially distributed data What is Geographic Information Systems (GIS) or Geospatial Information Technology (GIT)?

6 Example Smart Map 1 = Floodplain Map containing the horizontally controlled extent of the floodplain Smart Map 2 = Plat map containing location of structures and the their value Combined in a GIS– Tells you how many houses are in the floodplain and the value of the structures at risk

7 INTEGRATING GIS WITH WATERSHED MODELING Water Resources Division

8 RAINFALL-RUNOFF PROCESS RUNOFF INFILTRATION f (Land Use, Soil Types) WATERSHED BOUNDARY HYDROGRAPH f (Drainage Area, tc, Rainfall) Q T

9 The terrain data can viewed from any perspective.

10 Images can be draped over the terrain data.

11 Subbasin boundaries are delineated by simply designating outlets along the stream network anywhere within the watershed.

12 The area outside of the watershed is removed.

13 Land use data can be digitized from the orthophotos or imported in several common GIS formats.

14 GIS soils data can be obtained from the National Resources Conservation Service (NRCS), formerly SCS.

15 Composite Runoff Curve Numbers for each basin are automatically computed utilizing the land use and soils data.

16 NEXRAD data from historic rainfall events can be imported and used to calibrate the rainfall-runoff model

17 Hydrologic output graphics allow the user to quickly visualized the modeling results.

18 INTEGRATING GIS WITH HYDRAULIC MODELING Water Resources Division

19 Different aerial view of the stream valley

20 A DEM or TIN is used for the topography

21 The left and right overbank flow paths are digitized

22 Centerline, channel banks, and overbank flow paths brought onto TIN

23 Remaining cross sections “cut”. Now distances between cross sections are calculated along the centerline and in the left and right overbanks. Remaining cross sections “cut”. Now distances between cross sections are calculated along the centerline and in the left and right overbanks.

24 HEC-RAS calculates water surface profile

25 Water surface intersected with TIN yields floodplain boundaries

26 Floodplain on TIN

27 Aerial view of flooded stream valley

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31 INTEGRATING H&H RESULTS WITH OTHER DATA USING GIS TOOLS Water Resources Division

32 Sample data set – Napa Valley TIN & site aerial DOQQ

33 Sample data set – Contour development in ArcView

34 Sample data set – Migrating GIS data to HEC-RAS

35 Sample data set – Development of HEC-RAS model

36 Sample data set – 1-D hydraulic solution

37 Sample data set – Exporting HEC-RAS solutions to ArcView

38 Sample house data set – Napa Valley

39 Excel expansion of GIS shapefile table

40 Target site prior to start of storm event

41 Sample data set - 1 st time step No. Houses damaged: 18 Total damage: $237,349

42 Sample data set – 2nd time step No. houses damaged: 23 Total damage: $298,275

43 Sample data set – 3 rd time step No. houses damaged: 29 Total damage: $376,517

44 Sample data set – 4 th time step No. houses damaged: 36 Total damage: $460,957

45 Sample data set – 5 th time step No. houses damaged: 41 Total damage:$518,490

46 Sample data set – 6 th time step No. houses damaged: 44 Total damage: $559,249

47 Sample data set – 7 th time step No. houses damaged: 50 Total damage: $638,018

48 Sample data set – 8 th time step - Peak discharge No. houses damaged: 52 Total damage: $665,099

49 QUESTIONS??