Arc Hydro groundwater data model: a data model for groundwater systems within ArcGIS

1. Arc Hydro groundwater data model:a data model for groundwater systems within ArcGIS Gil Strassberg and David Maidment, University of Texas at Austin Norman Jones, Brigham Young University ESRI user conference May 2004

2. Modeling Geodatabase Hydrologic Information Systems A hydrologic information system is a combination of geospatial and temporal hydrologic data with hydrologic models that supports hydrologic practice, science and education

3. Arc Hydro An ArcGIS data model for water resources Arc Hydro toolset for implementation Framework for linking hydrologic simulation models Arc Hydro: GIS for Water Resources The Arc Hydro data model and application tools are in the public domain

4. Arc Hydro — Hydrography

5. Arc Hydro — Hydrology

6. Arc Hydro surface water A data model for representing surface water systems

7. Describing the hydrologic cycle

8. Objective Extend the Arc Hydro data model to include a representation of groundwater systems. Data model goals • Support representation of regional groundwater systems. • Support representation of site scale groundwater studies. • Enable the integration of surface water and groundwater data. • Connect to groundwater modeling software.

9. Regional groundwater systems • Usually the horizontal scale >> vertical scale • In many cases modeled as 2 dimensional

10. Site scale groundwater studies Characterization of Savannah River Site in South Carolina • Usually model 3D flow to study mass transport • Important to establish a 3D model of the system

11. Integration of surface water and groundwater information Need to represent movement of water between the surface and subsurface Geographic relationship between the surface and groundwater elements Complex subject!!

12. Connection to groundwater models Data model = Database Model input Model outputs

13. Data model framework Features describing the hydrogeology of the system Table that describes hydrogeologic units and their properties Features used in relation with modeling Raster catalog to represent geologic formations and parameter distribution Raster catalog to represent water related parameters Describes surfaces

14. Hydrogeology feature dataset Objects describing hydrogeology GeoLine (2D line) GeoArea (2D Polygon) GeoPoint (3D Point) GeoVolume (Multipatch) GeoSection (3D polygon) BoreLine (3D line)

15. Hydrogeology feature dataset Wells (points) Aquifer (2D Polygon) Water Area (2D Polygon) Water Line (2D line)

16. GeoRasters Raster catalog • GeoRasters: • Distribution of properties • Define boundaries of hydrogeologic units Transmisivity Hydraulic conductivity Top of formation Formation base GeoRasters are usually constant over time Woodbine aquifer, Texas

17. Raster Series describe water related properties over time Potentiometric surface Saturated thickness Contaminant concentration

18. Modeling feature dataset Connection to modeling tools: enable the preparation of model inputs and communication of model outputs 2 dimensional models 3 dimensional models

19. Hydrogeologic unit Describes the hydrogeologic unit and links together the spatial representations Hydrogeologic unit table

20. Example 1:Representing hydrogeology of an aquifer system North Carolina coastal aquifer system

21. Introduction to the Arc Hydro Groundwater toolbar Definition Query tool Create Volume objects from feature or import from external sources Create Volume objects from base polygons by extrusion Generate BoreLines from wells • Available on the CD • Available on CRWR website:

22. North Carolina coastal aquifer system Section line * From USGS, Water Resources Data Report of North Carolina for WY 2002

23. Defining the control volume This control volume is the boundary of the Neuse River basin down to a specified depth Next step - Describe the subsurface within this control volume

24. Boundaries of aquifers Map view of the aquifers

25. Beaufort aquifer A display of the water quality zones in the aquifer Outline of the Neuse River Basin

26. Hydrostratigraphy information Hydrostratigraphy from boreholes in the Beaufort boundary North Carolina Division of Water Resources website

27. Hydrostratigraphy attributes Attributes of the borehole describe the hydrostratigraphy at varying depths Elevations above mean sea level Land surface elevation Castle Hayne confining layer top Castle Hayne aquifer top Beaufort confining layer top Beaufort aquifer top

28. 3D view of the information Start from a 2D point (X, Y) with attributes describing the Z dimension Conceptual description of the subsurface Elevations are feet above mean sea level 8 Land surface elevation -22 Castle Hayne confining layer -29 Castle Hayne aquifer -123 Beaufort confining layer -133 Beaufort aquifer -334

29. Transform into 3D lines The HydroID relates the vertical description of hydrogeologic units back to the borehole point Hydro ID = 66

30. Transform into 3D lines Given the X and Y coordinates and the Z coordinate for the hydrogeologic units, 3 dimensional lines can be generated to represent the hydrostratigraphy within the borehole

31. Interpolate to create a model of the subsurface Interpolating to create cross section views Cross sections, fence diagrams

32. Interpolate to create a model of the subsurface Creating solid models Beaufort confining layer Beaufort aquifer Using external models we can compute the volume of the solids

33. Analysis Once we have a model of the subsurface we can look at interaction between control volumes and how water will move between them Streams Recharge zones

34. Introduction to Multipatches Multipatches in ArcGIS A multipatch is a series of three-dimensional surfaces that are represented as groups of geometries We can use closed multipatches to represent the geometry of volume objects Limitations: Not a true volume object, doesn’t know its volume, surface area etc. No ability to do intersections, proximity and other operations available on points, lines, and polygons in 2D space

35. Importing Solids from XML Interpolation in external software (for example GMS) Stratigraphy information in a spatial database Back to spatial database Store solids in XML

36. Demo 1: Creating BoreLines and GeoVolumes Create a control volume from the Neuse River Bain polygon by extruding between two values. Use the Definition Query tool to display only hydrostratigraphy wells. Then make a well selection and create borelines using the wells to borelines tool. Select a set of borelines for a specific aquifer (Black Creek), then create a GeoVolume of the aquifer using the BoreLines to GeoVolume tool. Display time series for the wells (water elevations) in ArcMap.

37. Example 2:Representing groundwater models Savannah River Site, South Carolina

38. Connection to groundwater models Data model = Database Model input Model outputs

39. Savannah River Site South Carolina Savannah River Site Radioactive waste burial ground

40. Conceptual model horizontal dimension Radioactive burial ground General head boundaries Package Streams

41. Conceptual model vertical dimension 270 - 300 Zone IIB2 “Water Table” 190 “Tan Clay” 180 5 layers in the conceptual model Zone IIB1 “Barnwell / McBean” 130 “Green Clay” 125 Zone IIA Gordon aquifer 50 (feet)

42. GIS representation of the horizontal dimension Represent the horizontal properties of the surface within ArcMap 3000 m 1600 m Each cell is 100 meters by 100 meters

43. Create a 3 dimensional representation of the model Control volume for the model domain Each cell in the 2D representation is transformed into a 3D object (Multipatch) Vertical dimension ~ 75 meters Can generate a 3D model in ArcScene

44. Views of the subsurface Once a solid model is constructed we can generate views of the subsurface Cross section along streams intersecting the model domain

45. Cell2D Cell3D Can relate the 3D Cells to modeling information Model inputs and outputs

46. To Review the Groundwater Data ModelPlease see “Groundwater” athttp://support.esri.com/datamodels To Get Latest Groundwater ToolsPlease see “Groundwater” athttp://http://www.crwr.utexas.edu/gis/gishydro04/