1. 1 Byung Sik, Kim Kangwon National University Advanced Hydrology and Water Resources Management

3. Introduction to GIS

4. Presentation Outline Using GIS to connect hydrology and meteorology Representation of spatial objects in GIS Terrain analysis using Digital Elevation Models Geodesy and map projections

5. Hydrologic Cycle: Connecting the Land Surface with the Atmosphere

6. Connecting Hydrology and Meteorology Two Spatial Scales –Drainage basin scale for consideration of severe storms and flood (Nexrad radar precipation as input, flood runoff as output) –Regional or global scale for consideration of climate change (Global climate models as input, time series of river flows as output)

7. Regional flood analysis in Houston Study region

8. Nexrad Rainfall for Storm of Oct 1994

9. Discharge in Buffalo Bayou at Katy October, 1994 storm

10. Calibrated Flow with HEC-HMS

11. Global Runoff (mm/yr) According to NCAR’s CCM3.2 Global Climate Model (GCM)

12. GTOPO30 - 30” Digital Elevation Model of the Earth Source: http://edcwww.cr.usgs.gov/landdaac/gtopo30/gtopo30.html

13. Drainage in North America Source: http://edcwww.cr.usgs.gov/landdaac/gtopo30/hydro/namerica.html

14. Drainage Basins of North America Source: http://edcwww.cr.usgs.gov/landdaac/gtopo30/hydro/ na_basins.html

15. Streamflow Hydrographs for Large Basins Amazon River Yangtze River Congo River MacKenzie River Runoff Input from Climate Model Streamflow Output at River Mouth

16. A Fundamental Dilemma Land Surface Hydrology has: –drainage patterns organized by rivers and watersheds which are spatially discrete –analysis in Cartesian coordinates (x,y,z) Atmospheric Science has: –circulation patterns which are spatially continuous over the earth –analysis in Geographic coordinates ( ,, z) GIS can be used to connect these two spatial frameworks

17. Presentation Outline Using GIS to connect hydrology and meteorology Representation of spatial objects in GIS Terrain analysis using Digital Elevation Models Geodesy and map projections

18. Discrete and Continuous Space Discrete Space: Vector GIS Continuous Space: Raster GIS

19. Geospatial Database: a set of compatible data layers or themes

20. Spatial Data: Vector format Point Point - a pair of x and y coordinates (x 1,y 1 ) Line Line - a sequence of points Polygon Polygon - a closed set of lines Node vertex Vector data are defined spatially:

21. Feature Attribute Table Fields Records

22. Relational Linkages Spatial Attributes Descriptive Attributes Water Right Locations

23. Locations on the Stream Network Digital Stream Network Connects Control Point Locations

24. Watersheds defined using a Digital Elevation Model

25. Spatial Data: Raster format Number of rows Number of Columns (X,Y) Cell size NODATA cell Definition of a Grid in GIS

26. Points as Cells

27. Line as a Sequence of Cells

28. Polygon as a Zone of Cells

29. Raster-Vector Data Model Raster Vector Real World

30. Presentation Outline Using GIS to connect hydrology and meteorology Representation of spatial objects in GIS Terrain analysis using Digital Elevation Models Geodesy and map projections

31. Study Region in West Austin Hog Pen Ck 4 km

32. Watershed Delineation by Hand Digitizing Watershed divide Drainage direction Outlet

33. 30 Meter Mesh Standard for 1:24,000 Scale Maps

34. DEM Elevations Contours 720 700 680 740 680700720740 720

35. DEM Elevations Contours 700 680

36. 32 16 8 64 4 128 1 2 Eight Direction Pour Point Model

37. 675649 534437 585522 1 675649 534437 585522 1 Slope: Direction of Steepest Descent

38. 22448 1216 12484 1281248 21444 11 Flow Direction Grid

39. Austin West 30 Meter DEM Elevations in meters ftp://ftp.tnris.state.tx.us/tnris/demA.html

40. Flow Direction Grid 32 16 8 64 4 128 1 2

41. Grid Network

42. 00000 0 0 0 0 0 0 0 0 032 2 11 1 1 15 25 24 1 00 0 00 0 0 0 0 0 0 0 0 0 322 11 1 1 1 2 15 245 Flow Accumulation Grid LinkLink to Grid calculator

43. 00 0 00 0 0 0 0 0 0 0 0 0 322 11 1 1 1 2 15 245 Flow Accumulation > 5 Cell Threshold

44. Stream Network for 5 cell Threshold Drainage Area 00000 0 0 0 0 0 0 0 0 032 2 11 1 1 15 25 24 1

45. Streams with 200 cell Threshold (>18 hectares or 13.5 acres drainage area)

46. Watershed Outlet

47. Watershed Draining to This Outlet

58. Watershed and Drainage Paths Delineated from 30m DEM Automated method is more consistent than hand delineation

59. DEM Data Sources 30m DEMs from 1:24,000 scale maps (urban watersheds) 3" (100m) DEMs from 1:250,000 scale maps (rural watersheds) 15" (500m) DEM for the US resampled from 3” DEM (large drainage basins) 30" (1km) DEM of the earth (GTOPO30)

60. Presentation Outline Using GIS to connect hydrology and meteorology Representation of spatial objects in GIS Terrain analysis using Digital Elevation Models Geodesy and map projections

61. Coordinate System (  o, o ) (x o,y o ) X Y Origin A planar coordinate system is defined by a pair of orthogonal (x,y) axes drawn through an origin

62. Earth to Globe to Map Representative Fraction Globe distance Earth distance = Map Scale: Map Projection: Scale Factor Map distance Globe distance = (e.g. 1:24,000) (e.g. 0.9996)

63. Map-Based Flood Hydrology and Hydraulics

64. Map-Based Hydrology and Hydraulics Connecting ArcView with HMS for the Austin Region Flood simulation using Nexrad data in Houston HMS-RAS for Waller Creek in Austin Creating flood plain maps in Waller Creek

65. Map-Based Hydrology and Hydraulics ArcView Input Data DEM HEC-HMS Flood discharge HEC-RAS Water surface profiles ArcView Flood plain maps CRWR-PrePro

66. Austin Digital Elevation Model Waller Creek

67. Austin Watersheds

68. CRWR-PrePro ArcView-based preprocessor for HEC-Hydrologic Modeling System (HEC-HMS) Digital Elevation Model Stream Map HMS Basin File Control point locations

69. DEM Watersheds for Austin

70. Selected Watersheds and Streams Mansfield Dam Colorado River

71. HMS Schematic Prepared with CRWR-PrePro Mansfield Dam Colorado River

72. HMS Basin File Basin file is a text description of all hydrologic elements 155 33 87 39Subbasin Junction Reach

73. HMS Model of the Austin Region

74. Design Precipitation Input

75. HMS Control File

76. HMS Results Watershed 155Junction 44

77. Map-Based Hydrology and Hydraulics Connecting ArcView with HMS for the Austin Region Flood simulation using Nexrad data in Houston HMS-RAS for Waller Creek in Austin Creating flood plain maps in Waller Creek

78. Regional flood analysis in Houston Study region

79. Study Region in West Houston Maps Developed using CRWR-Prepro by Seth Ahrens

80. Nexrad Rainfall for Storm of Oct 1994

81. Discharge in Buffalo Bayou at Katy October, 1994 storm

82. Calibrated Flow with HEC-HMS

83. Map-Based Hydrology and Hydraulics Connecting ArcView with HMS for the Austin Region Flood simulation using Nexrad data in Houston HMS-RAS for Waller Creek in Austin Creating flood plain maps in Waller Creek

84. Waller Creek DEM

85. Waller Creek Watershed Outlets

86. Waller Creek HMS Model

87. Flood Plain Mapping

88. Connecting HMS and RAS

89. Discharge at a Particular Cross-Section

90. Map-Based Hydrology and Hydraulics Connecting ArcView with HMS for the Austin Region Flood simulation using Nexrad data in Houston HMS-RAS for Waller Creek in Austin Creating flood plain maps in Waller Creek

91. HEC-RAS: Background Hydraulic model of the U.S. Army Corps of Engineers Input = cross-section geometry and flow rates Output = flood water elevations Cross-Section Schematic

92. Points describe channel and floodway geometry Bank station locations Water surface elevations and floodplain boundaries HEC-RAS: Cross-Section Description

93. HEC-RAS: Output Text File Graphical

94. Data translation from HEC-RAS text file to dbase table Bank and floodplain boundaries measured from stream centerline HEC-RAS: Data Translation

95. Digital orthophotograph and road coverage used as a base map User digitizes stream with mouse Boundary points define the RAS stream Digital Stream Mapping

96. Floodplain Mapping: Plan View

97. 3D Terrain Modeling: Ultimate Goal

98. For more information about GIS and Hydrology, see http://www.ce.utexas.edu/prof/maidment To obtain CRWR-PrePro to link ArcView with HEC-HMS, see http://www.ce.utexas.edu/prof/olivera/prepro/prepro.htm To take an online spatial hydrology course, see http://campus.esri.com/campus/home/home.cfm Web Links