1. Arc Hydro Groundwater Data Model
Gil Strassberg, David Maidment
University of Texas at Austin
Norman Jones, Brigham Young University

2. Outline Background: objectives, previous design
New design and books, Framework
Groundwater components
Examples

3. What is a hydrologic data model?
Booch et al. defined a model: “a simplification of reality created to better understand the system being created”
Objects
Aquifer
stream
Well
Volume
R.M. Hirsch, USGS

4. Developing a groundwater data model
Take a variety of spatial information and integrate into one geospatial database with a common terminology
Better communication
Integration of data
Base for applications
Geologic maps
Time series observations
Borehole data
Groundwater data model
(geospatial database)
Hydrostratigraphy
Geospatial vector layers
Numerical models
Gridded data

5. Goals of the Arc Hydro groundwater data model
Objective:
Develop a geographic data model for representing groundwater systems.
Data model goals:
Support representation of regional groundwater systems.
Support the representation of site scale groundwater data.
Enable the integration of surface water and groundwater data.
Facilitate the Integration of groundwater simulation models with GIS.

6. Regional groundwater systems
Describe groundwater systems from recharge to discharge
In many cases assumed as 2D systems, vertical scale >> horizontal scale

7. Site scale data Describe groundwater data in a small area of interest.
Usually includes 3D data (e.g. multilevel samplers, cores).
Multilevel samplers in the MADE site in Mississippi
Photographs provided by Chunmiao Zheng

8. Integration of surface water and groundwater data
Describe the relationship between surface water features ( e.g. streams and waterbodies) with groundwater features (aquifers, wells).
Enable the connection with the surface water data model
Hydro network
Aquifers

9. Integration of groundwater simulation models with GIS
Define data structures for representing groundwater simulation models within GIS.
Support spatial and temporal referencing of model data – allows the display and analysis of model data within a “real” geospatial and temporal context.
Focus on modflow as the standard model used in the groundwater community
Non spatial representation (layer, row, column)
Geospatial representation (x, y, and z coordinates)

10. Old design One big geodatabase with 3 conceptual components:
Hydrogeology, Simulation, Temporal

11. Outline Background: objectives, previous design
New design and books, Framework
Groundwater components
Examples

12. New Design Better integrate surface water and groundwater
Easier implementation
Solution:
One framework – including basic surface water and groundwater features
Componentize the data model smaller thematic pieces

13. Components
Components can be added to the framework to represent specific themes in more detail
Surface water components
Groundwater components
Network
Wells and boreholes
Framework
Drainage
Hydrostratigraphy
Hydrography
Geology
Chanel
Simulation
Temporal (enhanced)
Temporal component

14. Space and Time (technical)
Two books
Surface water
Groundwater
Introduction
Framework
Space and Time (technical)
3D ArcGIS (technical)
Hydro networks
Geology
Watersheds
Wells and Boreholes
River channels
Hydrostratigraphy
Temporal
Simulation
Implementation

15. Framework
Groundwater features
Surface water features
Time Series

16. Framework Watershed Waterbody HydroPoint Stream Aquifer Well
MonitoringPoint
Time Series

17. Surface water and groundwater
In many cases data are collected and stored separately
Store, visualize, and analyze data in the same context
Well in the Edwards Aquifer (state well )
Streamflow Gage at Comal Springs, New Braunfels Texas

18. Aquifer features
Polygon features for representing aquifer boundaries and zones within them
Map of major aquifers in Texas
Edwards Aquifer

19. Aquifer features
An aquifer is defined by one or a set of polygon features
Aquifer features can be grouped by a hydrogeologic unit id (HGUID)
FType for defining types of aquifer features

20. Well features Wells represented as 2D point features
State well number
Types of wells
Wells represented as 2D point features
Can be related with a certain Aquifer
FType for defining types of wells

21. Hydro Features
HydroID – Unique ID within the geodatabase (internal relationships) – Every feature in Arc Hydro is assigned a unique HydroID
HydroCode – Public identifier (external relationships)

22. HydroCode links to external applications
Web interface for groundwater data in Texas
Texas Water Information Integration & Dissemination (WIID)
The state well number becomes the HydroCode of the Well feature in Arc Hydro

23. Aquifer and well
Well 1729
State well number

24. Wells and TimeSeries
Well features are related with time series (water levels, water quality)

25. Surface water features
Watershed – Polygon features for representing a drainage area
Stream – Line features representing the path of flow as linear hydrographic features (blue lines on a map)
Waterbody – Polygon features representing water bodies
HydroPoint – Point features for representing any point hydrographic feature (diversion, spring, dam, etc.)

26. MonitoringPoint has time series
Monitoring points are related with time series (streamflow, water quality, precipitation)

27. Surface water – groundwater linkage
AquiferID is added to the surface water features
Surface water and groundwater features can be linked through the AquiferID and HydroID attributes
Work in progress –still trying to figure out exactly which relationships are needed

28. Surface water – groundwater linkage
Relationships between surface water and aquifer enable analysis based on spatial and hydrologic relationships
Stream reaches overlying an aquifer outcrop

29. Outline Background: objectives, previous design
New design and books, Framework
Groundwater components
Examples

30. Components Geology - mostly representation of data from geologic maps
Wells and Boreholes – Description of well attributes and vertical data along wells
Hydrostratigraphy – 2D and 3D description of hydrostratigraphy
Temporal - Representing time series data
Simulation – Representation of groundwater simulation models

31. Geology Features for representing data from geologic maps Faults Caves
Data from USGS report:

32. Components Geology - mostly representation of data from geologic maps
Wells and Boreholes – Description of well attributes and vertical data along wells
Hydrostratigraphy – 2D and 3D description of hydrostratigraphy
Temporal - Representing time series data
Simulation – representation of groundwater simulation models

33. Well Wells are the most basic features in groundwater databases
Attributes of wells describe its location, depth, water use, owner, etc.
In many cases these data are collected from driller reports

34. Wells in the Edwards Aquifer
The Well location is defined as a 2D point in the Well feature class
In the Arc Hydro model we only predefine a set of basic attributes
Wells in the Edwards Aquifer

35. Wells and 3D data 3D data is referenced along the well
From depth (top) – To depth (bottom)
From To

36. Wells and Boreholes
Vertical data (stratigraphy, casing) are related with wells
3D information is stored as tabular data in the VerticalMeasurements table
Can create 3D features (points, lines) for visualization

37. Creating 3D displays
We can create 3D displays of wells with the elevation and depth attributes of the well feature
Land surface
Extruded well features

38. 3D features (BorePoints and BoreLines)
Data on 3D intervals/points along the well
Wells with hydrostratigraphic information

39. 3D features (BorePoints and BoreLines)
Original data is in text format
Each data represents the top of a formation at one well
Data from USGS report:

40. 3D features (BorePoints and BoreLines)
Data on 3D intervals/points along the well are stored in tabular format
Well HydroID = 3266

41. 3D features (BorePoints and BoreLines)
Combining the well geometry (x, y) and the vertical measurements we can describe a set of 3D geometries (x, y, z)
146
128
-60 41
-81
750
-140
-217
-372
-433
Georgetown Fm. (GTOWN)
Cyclic + Marine member (CYMRN)
Upper confining unit
Leached + collapsed member (LCCLP)
Regional dense member (RGDNS)
Grainstone member (GRNSTN)
Kirschberg evaporite member (KSCH)
Dolomitic member (DOLO)
Lower confining unit, upper Glen Rose (UGLRS)

42. 3D features (BorePoints and BoreLines)
BorePoints representing geologic contacts along wells
Each point represents the top of a hydrogeologic formation
Well
Land surface
BorePoint

43. 3D features (BorePoints and BoreLines)
BoreLines representing intervals along wells
Each line represents a hydrogeologic unit (top and bottom)
Well HydroID = 3266
BoreLines for well 3266
BorePoints and BoreLines can also be used to represent other features along wells (construction, sampling ports, screens)

44. Components Geology - mostly representation of data from geologic maps
Wells and Boreholes – Description of well attributes and vertical data along wells
Hydrostratigraphy – 2D and 3D description of hydrostratigraphy
Temporal - Representing time series data
Simulation – representation of groundwater simulation models

45. Geology to hydrogeology
Stratigraphic units are usually grouped into hydrogeologic units
An aquifer can have a number of hydrogeologic units
Definition may change based on scale (local vs. regional) and purpose
Stratigraphic units
Hydrogeologic units
Upper confining unit
Georgetown Fm. (GTOWN)
Georgetown Fm.
Cyclic + Marine member (CYMRN)
Pearson Fm.
Leached + collapsed member (LCCLP)
Edwards Aquifer
Regional dense member (RGDNS)
Grainstone member (GRNSTN)
Kirschberg evaporite member (KSCH)
Kainer Fm.
Dolomitic member (DOLO)
Basal Nodular member (BSNOD)
Upper Glen Rose (UGLRS)

46. Products and workflow

47. Hydrostratigraphy
HydroGeologicUnit table provides a conceptual description of hydrogeologic units
Spatial features
Relates with spatial features representing instances of the HGU

48. BorePoints representing top of hydrogeologic units
HGUArea
2D polygons defining boundaries of hydrogeologic units
BorePoints representing top of hydrogeologic units
Kainer boundary
Georgetown boundary

49. GeoSection 3D polygons representing cross sections
SectionLine defines the 2D cross section line
Section line connecting a sequence of wells
Section A-A’
(HydroID = 4666)

50. GeoSection
Each polygon is part of a section group defined by the SectionID
The SectionID of the polygon relates back to the section line
Section A-A’
(HydroID = 4666)

51. GeoRasters Raster catalog for storing and indexing raster datasets
Can store top and bottom of formations
Each raster is related with a HGU in the hydrogeologic unit table
Georgetown
Person
Kainer
Glen Rose

52. Raster of hydraulic conductivity in the Edwards Aquifer
GeoRasters
GeoRasters also store hydraulic properties such as transmissivity, conductivity, and specific yield
K (feet/day)
Raster of hydraulic conductivity in the Edwards Aquifer

53. GeoVolume
Objects for representing 3D volumes
Geometry is multipatch

54. GeoVolumes in the geodatabase
Can create the volumes as a set of 3D triangles
Not real volume – can’t do any 3D operations
Volumes in this example were generated in GMS and imported to the geodatabase
Volumes in GMS
Georgetown
Person
Kainer
GeoVolumes in the geodatabase

55. Derived GeoSections
GeoSections can also be created by “cutting” through GeoVolumes
C-C’
D-D’
E-E’
E-E’
D-D’
C-C’
GeoSections
Section lines on a 2D view of GeoVolumes
Derived 3D GeoSections

56. Components
Geology - mostly representation of geologic data from geologic maps
Wells and Boreholes – Description of well attributes and vertical data along wells
Hydrostratigraphy – 2D and 3D description of hydrostratigraphy
Temporal - Representing time series data
Simulation – representation of groundwater simulation models

57. Types of time varying datasets
Single variable time series – A single variable recorded at a location, such as stream discharge or groundwater levels
Multi variable time series – Multiple variables recorded simultaneously at the same location, such as chemical analysis of a water sample
Time varying surfaces (raster series) – Raster datasets indexed by time. Each rater is a “snapshot” of the environment at a certain time.
Time varying features (feature series) – A collection of features indexed by time. Each feature in a feature series represents a variable at a single time period.

58. TimeSeries and TSType
Each measurement is indexed by space, time, and type
Space = FeatureID
Time = TSDateTime
Type = TSTypeID
FeatureID
TSDateTime
TSTypeID
TSType provides information on the time series

59. Query by location and type (FeatureID = 2791 TSTypeID = 2)
Getting data views
We can “slice” through the data cube to get specific views of the data
What?
Where and What?
Where?
Query by location
(FeatureID = 2791)
Query by type
(TSTypeID = 2)
Query by location and type
(FeatureID = 2791 TSTypeID = 2)
FeatureID
TSDateTime
TSTypeID
2791
FeatureID
TSDateTime
TSTypeID 2
FeatureID
TSDateTime
TSTypeID 2
2791

60. Get all the data of TSType 2 measured at Feature 2791
Data views
Get all the data of TSType 2 measured at Feature 2791

61. Data views
FeatureID of the time series = HydroID of the spatial feature (e.g. Well)
TSTypeID relates to the TSType table
Well HydroID = 2791

62. TimeSeries Table A query by location (FeatureID) and type (TSTypeID)
Create a plot of time series related to a feature
Well HydroID = 2791

63. Data views A type-time view: Get water levels (TSTypeID =2) for 2/2004
FeatureID
TSDateTime
TSTypeID 2
2/2004
Water level in the Edwards Aquifer in 2/2004
Set of layers for different times creates an animation

64. Multi-variable time series
Multiple variables recorded simultaneously at the same location
Indexed by location (FeatureID), and time (TSDateTime)
Example – water quality parameters
Variables

65. Multi-variable time series
Can query for multiple variables together
New Braunfels Springs
Well HydroID = 2833

66. RasterSeries Raster datasets indexed by time
Each raster represents a continuous surface describing a variable for a given time
January 1991
January 1992
January 1993

67. Feature Series A collection of features indexed by time
Example of particle tracks
Features are indexed by TSType, TSDateTime, and GroupID
Each group of features creates a track over time

68. Components
Geology - mostly representation of geologic data from geologic maps
Wells and Boreholes – Description of well attributes and vertical data along wells
Hydrostratigraphy – 2D and 3D description of hydrostratigraphy
Temporal - Representing time series data
Simulation – representation of groundwater simulation models

69. Representing simulation models
Georeference model inputs and outputs (in space and time)
Focus on MODFLOW, block centered finite difference grid (nodes are in the center of the cells)
Represent 2D and 3D models
Mesh-centered Finite difference grid
Block-centered finite difference grid
Finite element grid

70. Simulation Features for representing data from simulation models
Cell2D
Cell2D
Boundary
Model origin
Angle
Cell3D
Node
Node
Cell3D

71. Tools for read model inputs/outputs
Example – Create water budgets for selected cells
Water budget terms for the defined zone

72. Groundwater Modeling System
Through our research at the EMRL, we have developed three computer programs that are widely used both in the U.S. and internationally. The Surface Water Modeling System (SMS) is used to model flow in rivers, harbors, lakes, and estuaries and to design hydraulic structures. The Watershed Modeling System is used to model watershed runoff and perform flood forecasting, including flood inundation mapping. The Groundwater Modeling System (GMS) is used to manage ground water resources and to help protect and remediate contaminated groundwater.