Arc Hydro Groundwater Data Model

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Arc Hydro Groundwater Data Model

• Gil Strassberg (Aquaveo)

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Components

• Geology - Representation of data from geologic
  maps
• Wells and Boreholes Description of well
  attributes and borehole data
• Hydrostratigraphy 2D and 3D description of
  hydrostratigraphy
• Temporal Representation of time varying data
• Simulation Representation of groundwater
  simulation models (focus on MODFLOW)

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Geologic maps
A geologic map is a cartographic product that
portrays information about the geologic character
of a specific geographic area

• Groundwater features are closely tied to geology
• Geologic maps vary in scale (continental,
  regional, local)
• Provide a simple data structure to support
  mapping

Geology
Aquifers
Maps from the United States National
(http//nationalatlas.gov/).
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Geologic map databases
A digitally-compiled collection of spatial
(geographically referenced) and descriptive
geologic information about a specific geographic
area (Geologic Data Subcommittee, Federal
Geographic Data Committee 2006)

• Standards for archiving geologic map data
• Support the development of applications for
  automating map creation
• Complex
• Examples
• North American Geologic Map Data Model (NADM)
• National Geologic Map Database (NGMDB)
• State geologic map databases (e.g. Geologic Atlas
  of Texas)
• ArcGeology

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Geologic map databases
Geodatabase design for storing data from the
Geologic Atlas of Texas (http//www.tnris.org/news
.aspx?id244)
Arc Geology generic geologic map database
implemented within ArcGIS (figure from Raines et
al. 2007
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Geology component
GeologyPoint Point feature (e.g. springs, caves,
sinks, and observation points) GeologyLine Line
features (e.g. faults, contacts, and
dikes) GeologyArea Areal features (e.g. rock
units and alteration zones)
Map modified from Geologic map of the Edwards
Aquifer recharge zone, south-central Texas. U.S.
Geological Survey SIM 2873
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Demo Geology
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Components

• Geology - Representation of data from geologic
  maps
• Wells and Boreholes Description of well
  attributes and borehole data
• Hydrostratigraphy 2D and 3D description of
  hydrostratigraphy
• Temporal Representation of time varying data
• Simulation Representation of groundwater
  simulation models (focus on MODFLOW)

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Well databases

• Wells are basic features in groundwater databases
• Attributes of wells describe its location, depth,
  water use, owner, etc.
• Data are collected from drilling/construction
  reports and permits

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Well databases

• Well databases store information on wells and
  related data
• Data are related to wells such as construction,
  water levels, water quality, and stratigraphy
• Usually a central table is used to describe well
  features and other data are linked to it through
  key attributes (e.g. state well number)

Relationships in the TWDB groundwater database
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Well

• 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
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Borehole data

• 3D data (screens, completion intervals,
  stratigraphy) is referenced along the well
• From depth (top) To depth (bottom)

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BoreholeLog table

• Used to store 3D borehole data related with well
  features
• Each row in the table represents a point/interval
  along a borehole
• Data are related with a Well feature through the
  WellID attribute
• 3D geometry is defined by the TopElev and
  BottomElev attributes

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3D features (BorePoints and BoreLines)

• Can create 3D features representing data in the
  BoreholeLog table
• BorePoint is a 3D point feature class for
  representing point locations along a borehole
  (e.g. geologic contacts, samplers)
• BoreLine is a 3D line feature class for
  representing intervals along a borehole

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Demo Aquifer, Wells, and Borehole data
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Components

• Geology - Representation of data from geologic
  maps
• Wells and Boreholes Description of well
  attributes and borehole data
• Hydrostratigraphy 2D and 3D description of
  hydrostratigraphy
• Temporal Representation of time varying data
• Simulation Representation of groundwater
  simulation models (focus on MODFLOW)

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Hydrogeologic units

• Hydrogeologic unit is any soil or rock unit or
  zone which by virtue of its hydraulic properties
  has a distinct influence on the storage or
  movement of ground water (USGS glossary of
  hydrologic terms)

Hydrogeology can be derived by classifying
stratigraphic units
Stratigraphic units
Hydrogeologic units
Upper confining unit
Georgetown Fm.
Georgetown Fm. (GTOWN)
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)
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Hydrogeologic unit table

• HydroGeologicUnit table provides a conceptual
  description of hydrogeologic units
• Hydrogeologic units are with an AquiferID such
  that they can be grouped to represent an aquifer
• Spatial features are indexed with a HGUID to
  relate to the conceptual representation of the
  units

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Representations of hydrogeologic units

• Different spatial representations of
  hydrogeologic with 2D and 3D objects
• Workflow for creating 3D hydrogeologic models

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Hydrogeologic unit table

• Hydrogeologic units are described with different
  spatial instances (outcrops, borehole intervals,
  surfaces, cross sections, and volumes)
• HGUID is the key attribute

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HGUArea

• 2D polygons defining boundaries of hydrogeologic
  units
• HGUArea (conceptual/interpolated boundary) ?
  GeologyArea (mapped outcrop)

GeologyArea features represent data from geologic
maps
GeologyArea
Data points representing top elevations of the
Kainer formation
GeoArea feature representing the Kainer
hydrogeologic unit
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Representation of Cross Sections

• SectionLine defines the 2D cross section
• GeoSection represent 3D sections as 3D polygons
• SectionID of the polygon relates back to the
  section line

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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
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GeoRasters

• GeoRasters also store hydraulic properties such
  as transmissivity, conductivity, and specific
  yield

Raster of hydraulic conductivity in the Edwards
Aquifer
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GeoVolume

• Objects for representing 3D volume objects
• Geometry is multipatch

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GeoVolume

• Can create the volumes as a set of 3D triangles
• Not real volume cant do any 3D operations
• Volumes in this example were generated in GMS and
  imported to the geodatabase

Volumes in GMS
GeoVolumes in the geodatabase
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Demo Hydrostratigraphy
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Components

• Geology - Representation of data from geologic
  maps
• Wells and Boreholes Description of well
  attributes and borehole data
• Hydrostratigraphy 2D and 3D description of
  hydrostratigraphy
• Temporal Representation of time varying data
• Simulation Representation of groundwater
  simulation models (focus on MODFLOW)

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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.

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Time series

• The most basic case is a monitoring device
  recording values over time (e.g. monitoring well,
  streamflow gage)

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Time series

• TimeSeries table is the basic table for storing
  time series data
• Need to support what, where, and when
• Variables table defines variable objects

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Time series

• By querying the table we can create different
  data views

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Time series views create time series graph

• FeatureID of the time series HydroID of the
  spatial feature (e.g. Well)

Well HydroID 2791
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Time series views map a variable at a given time
Map a certain variable (e.g. water levels) at a
given time (e.g. February 2004)
Feet above mean sea level
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Multi-variable time series

• Data are indexed by space (FeatureID) and by time
  (TsTime) but instead of one variable we store
  multiple variables.
• The column heading is the variable key (VarKey)

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Multi-variable time series

• Data are indexed by space (FeatureID) and by time
  (TsTime) but instead of one variable we store
  multiple variables.
• The column heading is the variable key (VarKey)

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RasterSeries

• Raster datasets indexed by time
• Each raster represents a continuous surface
  describing a variable for a given time over an
  area of interest

January 1991
January 1992
January 1993
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Feature Series

• A collection of features indexed by time (e.g.
  particle tracks)
• Features are indexed by VariableID, TsTime.
• Features can also be indexed with a GroupID. Each
  group of features creates a track over time

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Demo Time Series
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Components

• Geology - Representation of data from geologic
  maps
• Wells and Boreholes Description of well
  attributes and borehole data
• Hydrostratigraphy 2D and 3D description of
  hydrostratigraphy
• Temporal Representation of time varying data
• Simulation Representation of groundwater
  simulation models (focus on MODFLOW)

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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

Block-centered finite difference grid
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Simulation component
Features for representing data from simulation
models
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Boundary
Polygon feature class for representing the extent
and orientation of a simulation model
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Cell2D and Node
Cell2D polygon feature class that represents
cells or elements associated with a
two-dimensional simulation model or a single
layer of a three-dimensional model Node point
feature class used in combination with Cell2D to
represent the models mesh/grid.

• Finite element mesh
• Mesh centered finite difference grid
• Cell centered finite difference grid

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Cell3D

• Multipatch feature class that represents
  three-dimensional cells and elements
• Used mostly for visualization of 3D models

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Demo Simulation (with demo of MODFLOW Analyst)