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

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Arc Hydro groundwater data modela 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

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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
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Arc Hydro GIS for Water Resources

• Arc Hydro
• An ArcGIS data model for water resources
• Arc Hydro toolset for implementation
• Framework for linking hydrologic simulation models

The Arc Hydro data model and application tools
are in the public domain
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Arc Hydro Hydrography
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Arc Hydro Hydrology
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Arc Hydro surface water
A data model for representing surface water
systems
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Describing the hydrologic cycle
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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.

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Regional groundwater systems

• Usually the horizontal scale gtgt vertical scale
• In many cases modeled as 2 dimensional

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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

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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!!
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Connection to groundwater models
Data model Database
Model input
Model outputs
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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
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Hydrogeology feature dataset
Objects describing hydrogeology
GeoLine (2D line)
GeoArea (2D Polygon)
GeoPoint (3D Point)
GeoSection (3D polygon)
GeoVolume (Multipatch)
BoreLine (3D line)
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Hydrogeology feature dataset
Aquifer (2D Polygon)
Wells (points)
Water Area (2D Polygon)
Water Line (2D line)
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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
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Raster Series
describe water related properties over time
Potentiometric surface
Saturated thickness
Contaminant concentration
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Modeling feature dataset
Connection to modeling tools enable the
preparation of model inputs and communication of
model outputs
3 dimensional models
2 dimensional models
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Hydrogeologic unit
Describes the hydrogeologic unit and links
together the spatial representations
Hydrogeologic unit table
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Example 1Representing hydrogeology of an
aquifer system

• North Carolina coastal aquifer system

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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

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North Carolina coastal aquifer system
Section line
From USGS, Water Resources Data Report of North
Carolina for WY 2002
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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
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Boundaries of aquifers
Map view of the aquifers
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Beaufort aquifer
A display of the water quality zones in the
aquifer
Outline of the Neuse River Basin
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Hydrostratigraphy information
Hydrostratigraphy from boreholes in the Beaufort
boundary
North Carolina Division of Water Resources website
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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
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3D view of the information
Start from a 2D point (X, Y) with attributes
describing the Z dimension
Conceptual description of the subsurface
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Elevations are feet above mean sea level
Land surface elevation
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Castle Hayne confining layer
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Castle Hayne aquifer
-123
Beaufort confining layer
-133
Beaufort aquifer
-334
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Transform into 3D lines
The HydroID relates the vertical description of
hydrogeologic units back to the borehole point
Hydro ID 66
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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
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Interpolate to create a model of the subsurface
Interpolating to create cross section views
Cross sections, fence diagrams
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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
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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
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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, doesnt
know its volume, surface area etc. No ability to
do intersections, proximity and other operations
available on points, lines, and polygons in 2D
space
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Importing Solids from XML
Interpolation in external software (for example
GMS)
Stratigraphy information in a spatial database
Store solids in XML
Back to spatial database
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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.

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Example 2Representing groundwater models

• Savannah River Site, South Carolina

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Connection to groundwater models
Data model Database
Model input
Model outputs
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Savannah River Site South Carolina
Savannah River Site Radioactive waste burial
ground
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Conceptual model horizontal dimension
Radioactive burial ground
General head boundaries Package
Streams
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Conceptual model vertical dimension
270 - 300
Zone IIB2 Water Table
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Tan Clay
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5 layers in the conceptual model
Zone IIB1 Barnwell / McBean
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Green Clay
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Zone IIA Gordon aquifer
50 (feet)
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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
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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
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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
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Can relate the 3D Cells to modeling information
Model inputs and outputs
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To Review the Groundwater Data ModelPlease see
Groundwater at http//support.esri.com/datamodel
s
To Get Latest Groundwater ToolsPlease see
Groundwater at http//http//www.crwr.utexas.edu
/gis/gishydro04/