1 Arc Hydro Groundwater Data Model This presentation is adapted from the Groundwater Preconference Seminar presented at the 2008 ESRI User Conference by David Maidment, Gil Strassberg, and Norman Jones The research described here is based on the PhD dissertation of Gil Strassberg, which is accessible at: ftp://ftp.crwr.utexas.edu/pub/outgoing/strassberg/GroundwaterDataModel/Documents/Dissertaion_Strassberg.pdf

2 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

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

4 Network Components Framework Surface water components Drainage Hydrography Channel Groundwater components Components can be added to the framework to represent specific themes in more detail Borehole data Hydrostratigraphy Geology Simulation Temporal (enhanced)

Arc Hydro GW Data Model 5

Arc Hydro Framework 6 Basic representation of surface water and groundwater Basic representation of surface water and groundwater Components can be added to the framework to represent specific themes in more detail Components can be added to the framework to represent specific themes in more detail

7 Well Wells are the most basic features in groundwater databases Attributes of wells describe its location, depth, water use, owner, etc.

8 Well Wells are defined as 2D point features Only some basic attributes are predefined to describe the well use, and geometry and relationship with aquifers Wells in the Edwards Aquifer

9 Aquifer features Polygon features for representing aquifer boundaries and zones within themPolygon features for representing aquifer boundaries and zones within them Representation of Aquifer mapsRepresentation of Aquifer maps

10 Aquifer features An aquifer is defined by one or a set of polygon features Aquifer features can be grouped by HGUID

Pre Conference Seminar11 Hydro Features Key attributes for feature identificationKey attributes for feature identification HydroID – Unique ID within the geodatabase (internal relationships)HydroID – Unique ID within the geodatabase (internal relationships) HydroCode – Public identifier (external relationships)HydroCode – Public identifier (external relationships)

Pre Conference Seminar12 HydroID A new ID assigned to features in a Arc Hydro geodatabaseA new ID assigned to features in a Arc Hydro geodatabase Uniquely identifies features with a geodatabaseUniquely identifies features with a geodatabase Is used to manage relationships between features and to relate features with tabular data (e.g. time series)Is used to manage relationships between features and to relate features with tabular data (e.g. time series) Custom tool for managing HydroIDsCustom tool for managing HydroIDs

Pre Conference Seminar13 HydroCode links to external applications Web interface for groundwater data in TexasWeb interface for groundwater data in Texas Texas Water Information Integration & Dissemination (WIID)Texas Water Information Integration & Dissemination (WIID)

14 Aquifer and well Well features are related to Aquifers: The AquiferID of a well feature is equal to the HydroID of an aquifer featureWell features are related to Aquifers: The AquiferID of a well feature is equal to the HydroID of an aquifer feature An aquifer can be associated with one or more wells (1:M relationship)An aquifer can be associated with one or more wells (1:M relationship) Can take a different approach to support M:N relationshipCan take a different approach to support M:N relationship

15 Aquifer and well Well HydroID = 53

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

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

Pre Conference Seminar 18 Integration of surface water and groundwater data Streamflow Gage at Comal Springs, New Braunfels Texas Well in the Edwards Aquifer) The common framework supports analysis of surface water and groundwater data together

Pre Conference Seminar19 Surface water groundwater linkage Relationships between surface water and aquifer enable analysis based on spatial and hydrologic relationships Streams over the outcrop = recharge features

20 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)

21 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 Groundwater features are closely tied to geology Geologic maps vary in scale (continental, regional, local) Geologic maps vary in scale (continental, regional, local) Provide a simple data structure to support mapping Provide a simple data structure to support mapping Geology Aquifers Maps from the United States National (

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

23 Geologic map databases Arc Geology: Arc Geology: generic geologic map database implemented within ArcGIS (figure from Raines et al Geodatabase design for storing data from the Geologic Atlas of Texas ( Geodatabase design for storing data from the Geologic Atlas of Texas ( )

Pre Conference Seminar24 Geology component Map modified from: Geologic map of the Edwards Aquifer recharge zone, south- central Texas. U.S. Geological Survey SIM 2873 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)

Pre Conference Seminar25 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)

26 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

Pre Conference Seminar27 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

Pre Conference Seminar28 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

29 Borehole data 3D data (screens, completion intervals, stratigraphy) is referenced along the well3D data (screens, completion intervals, stratigraphy) is referenced along the well From depth (top) – To depth (bottom)From depth (top) – To depth (bottom)

30 BoreholeLog table Used to store 3D borehole data related with well featuresUsed to store 3D borehole data related with well features Each row in the table represents a point/interval along a boreholeEach row in the table represents a point/interval along a borehole Data are related with a Well feature through the WellID attributeData are related with a Well feature through the WellID attribute 3D geometry is defined by the TopElev and BottomElev attributes3D geometry is defined by the TopElev and BottomElev attributes

31 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

32 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)

33 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 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) Upper Glen Rose (UGLRS) Stratigraphic units Hydrogeologic units Pearson Fm. Basal Nodular member (BSNOD) Kainer Fm. Georgetown Fm. Edwards Aquifer

34 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

35 Representations of hydrogeologic units Different spatial representations of hydrogeologic with 2D and 3D objects Workflow for creating 3D hydrogeologic models

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

37 HGUArea GeoArea feature representing the Kainer hydrogeologic unit GeologyArea features represent data from geologic maps GeologyArea 2D polygons defining boundaries of hydrogeologic units 2D polygons defining boundaries of hydrogeologic units HGUArea (conceptual/interpolated boundary) ≠ GeologyArea (mapped outcrop) HGUArea (conceptual/interpolated boundary) ≠ GeologyArea (mapped outcrop) Data points representing top elevations of the Kainer formation

38 Representation of Cross Sections SectionLine SectionLine defines the 2D cross section GeoSection represent 3D sections as 3D polygons GeoSection represent 3D sections as 3D polygons SectionID of the polygon relates back to the section line SectionID of the polygon relates back to the section line GeoSection 4713 HGUID = 3 A A’ B B’ A A’ B B’ Section B-B’ (HydroID 4667)

39 Georgetown Glen Rose Kainer Person 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

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

41 GeoVolume Objects for representing 3D volume objects Geometry is multipatch

42 GeoVolume 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 Georgetown Person Kainer Volumes in GMS GeoVolumes in the geodatabase

43 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)

44 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.

Pre Conference Seminar45 Time series The most basic case is a monitoring device recording values over time (e.g. monitoring well, streamflow gage) San Marcos springs Springs San Marcos River Sink Creek San Marcos Monitoring Well ( )

46 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 Time (TsTime) Space (FeatureID) Variables (VariableID)

Pre Conference Seminar47 Time series By querying the table we can create different data views 2791 TsTime FeatureID VariableID 2 FeatureID VariableID 2791FeatureID VariableID 2 (a)(b)(c)TsTime

48 Time series views – create time series graph Well HydroID = 2791 FeatureID of the time series = HydroID of the spatial feature (e.g. Well)FeatureID of the time series = HydroID of the spatial feature (e.g. Well)

Pre Conference Seminar49 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) FeatureID VariableID 2 TsTime 2/2004 Feet above mean sea level

Pre Conference Seminar50 Data are indexed by space (FeatureID) and by time (TsTime) but instead of one variable we store multiple variables. 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) The column heading is the variable key (VarKey) Variables (VarKey) Multi-variable time series

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

52 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

53 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

54 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)

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

56 Simulation component Features for representing data from simulation models

Pre Conference Seminar57 Boundary Polygon feature class for representing the extent and orientation of a simulation model

58 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 model’s mesh/grid. a)Finite element mesh b)Mesh centered finite difference grid c)Cell centered finite difference grid

59 Cell3D Multipatch feature class that represents three-dimensional cells and elements Used mostly for visualization of 3D models Used mostly for visualization of 3D models