1. Arc Hydro: GIS for Water Resources David R
Arc Hydro: GIS for Water Resources David R. Maidment University of Texas at Austin
Arc Hydro
Culmination of a 3-yr effort
GIS in Water Resources Consortium
Customization of ArcGIS for water resources
Arc Hydro toolset and application framework
Notes:
Industrial partners: ESRI, Danish Hydraulic Institute, Camp,Dresser and McKee, Dodson and Associates
Government partners:
Federal: EPA, USGS, Corps of Engineers (Hydrologic Engineering Center)
State: Texas Natural Resource Conservation Commission, Texas Water Development Board
Local: Lower Colorado River Authority, City of Austin, Dept of Watershed Protection
Academic Partners: University of Texas, Brigham Young University, Utah State University

2. GIS in Water Resources Consortium
CRWR
GIS in Water Resources Consortium
GIS
Water Resources
Bringing together these two communities by using a common geospatial data model

3. MS Access Oracle SQL Server Informix
ArcGIS Introduces
A new geographic data model
A new geographic database
Stored in an Relational Database (Geodatabase)
ArcObjects
Component Object Model (COM) objects that access geographic data
Works like MS Word, Excel, Powerpoint, ….
Geodatabase
MS Access Oracle SQL Server Informix
DB2
Feature
IFeature : IRow
IFeature
IFeatureBuffer
IFeatureBuffer : IRowBuffer
IFeatureDraw
IFeatureDraw : IUnknown

4. Geodatabase Model Geodatabase FeatureDataSet FeatureClass Feature
Collection of FeatureDataSets
Like a workspace
FeatureDataSet
Collection of FeatureClasses
Like a Coverage
FeatureClass
Collection of Features
Like a Coverage FeatureClass
Feature
Geographic Object
Row in DBMS Table

5. Features
Features are geographic objects stored in relational database tables
Feature location is an attribute of type shape
Point, Multipoint, Line, Polygon
Attributes and geometry are stored together not in separate files as in Arc Info 7 and ArcView 3
Feature (row)
Shape
OID
524
X,Y,Z,M, ...
Stream
Type
Channel
. . .
FeatureClass (table)

6. Feature DataSets
A holder for a set of feature classes having a common coordinate system and spatial extent
GeoDatabase
FeatureDataset
FeatureClass
Feature (row)
Shape
OID
524
X,Y,Z,M, ...
Stream
Type
Channel
. . .
FeatureClass (table)
Object Class

7. Extensible Data Model Row Feature Measurement NetworkFeature Basin
JunctionFeature
EdgeFeature
SimpleJunction
ComplexEdge
Confluence
Gage
Stream

8. What is Arc Hydro?
An data infrastructure for storing and integrating hydro data within ArcGIS
A set of hydro objects built on top of ArcObjects
A set of standardized attributes
A vocabulary for describing data (glossary)
A toolset for implementing the data model

9. Arc Hydro Components Drainage System Hydro Network Time Series
Flow
Time
Time Series
Channel System
Hydrography

10. Arc Hydro Data Model
Hydrography
Hydrology

11. Data Model Based on Inventory Streams Drainage Areas Hydrography
Channels
Terrain Surfaces
Rainfall Response
Digital Orthophotos

12. Data Model Based on Behavior
Follow a drop of water from where it falls on the land, to the stream, and all the way to the ocean.

13. Integrating Data Inventory using a Behavioral Model
Relationships between
objects linked by tracing path
of water movement

14. Arc Hydro USA Arc Hydro Framework dataset for USA at 1:500,000 scale
Built from USGS and National Weather Service data
MonitoringPoints are USGS stream gaging stations
Arc Hydro USA is an integrated Arc Hydro dataset for the continental United States built using:
USGS Extended Reach File 1 for HydroEdges
USGS 8-digit Hydrologic Unit watersheds for Watersheds
National Weather Service Lakes file for Waterbodies
USGS Streamflow gaging station file (active stations only) for HydroPoints
The streamlines from the reach file have been built into a Hydro Network.
The total size of this file as a personal geodatabase is 1.8GB

15. Arc Hydro Framework Input Data
Watersheds
Waterbody
Streams
The Arc Hydro Framework is a simplified version of the full Arc Hydro data model designed for an entry level user who just wants to put together a basic data set for streams, watersheds, waterbodies and hydro points like stream gages and water quality monitoring points
Monitoring Points

16. Arc Hydro Framework
The Arc Hydro framework is built on a Hydro Network made up of HydroEdges (stream lines) and HydroJunctions (points of interest on the lines). The watersheds, waterbodies and hydropoints are connected to the hydronetwork using relationships with the hydro junctions (blue lines in the diagram).

17. Arc Hydro Framework Dataset for the Guadalupe Basin

18. HydroNetwork through Canyon Lake
Flowlines through water body
Generic Junction
(for topological connection of edges)

19. HydroJunction has Waterbody Relationship

20. National Hydro Data Programs http://www. crwr. utexas
National Elevation Dataset
(NED)
National Hydrography Dataset
(NHD)
Elevation Derivatives for
National Application (EDNA)
Watershed Boundary Dataset

21. Hydrologic Cataloging Units (HUCS)
Hydrologic Unit Code =
Guadalupe Basin
(4 HUC’s)
2015 HUC’s cover continental US
average area ~ 1 county

22. Watersheds of the Guadalupe Basin
NWS forecast
Watersheds
(flooding)
Guadalupe
HydroNetwork
EPA TMDL
Segments
(water quality)
TNRCC water
availability points
(water supply)

23. Regional Analysis
HydroNetwork to provide connectivity of flow through large regions
Digital elevation model
for terrain analysis within
basins

24. Scales of representation of Drainage Systems
Basins – drainage areas for water
resources management
Watersheds – subdivision of Basin
for a particular hydrologic purpose
Catchments – subdivision of Basin into elementary drainage areas by physical rules
Digital Elevation Model –
land surface terrain grid cells

25. Catchments, DrainageLines and DrainagePoints

26. Catchments Subdivided at Watershed Outlet

27. EDNA Catchments Average area = 7.5 km2
Designed for remapping of Nexrad
data onto drainage units

28. Arc Hydro Time Series Object
TSDateTime
TSValue
FeatureID
TSType

29. National Water Information System
Web access to USGS
water resources data
Arc Hydro NWIS data
retrieval tool

30. HydroID and HydroCode

31. Retrieving NWIS Data
Select Gage Layer
Enter Period of Record

32. Streamflow Time Series
Arc Hydro Time Series Table

33. Time Series Extracted to Excel (In Excel, use Data/Get External Data to query Geodatabase)
view
Geodatabase
view

35. HRAP Cells for Nexrad Data
Average area = 14.5 km2

36. Coupling Spatial and Temporal Data
1 hour Nexrad Rainfall
on the Guadalupe Basin
October 13, 2001

37. Water Balance in the Landscape
Atmospheric Water
Precipitation
Evaporation
Runoff
Soil Water
Surface Water
Recharge
Baseflow
Groundwater

38. EDNA Catchments
Average area = 7.5 km2

39. Intersection of Nexrad and Catchments
Surface Water Balance
Atmospheric Water
Soil Water
Surface Water

40. Modflow Groundwater Cells
Modflow Model of the
Edwards-Trinity
aquifer
Average area = 2.6 km2

41. Intersection of Nexrad and Modflow Cells
Atmospheric Water
Groundwater
Balance
Groundwater

42. Intersection of Nexrad, Catchments and Modflow
Atmospheric Water
Soil Water
Surface Water
Groundwater

43. What software do you need?
ArcView 8.2
Viewing, querying existing geodatabases
Editing feature classes and adding data
Spatial Analyst for ArcGIS
To operate the raster tools in Arc Hydro
ArcInfo 8.2
To build geometric networks and create new relationships

44. Arc Hydro Tools Version 1.0
Raster processing
DEM processing
Watershed delineation
Vector processing
Arc Hydro attributes
Network analysis
Time Series and Application Utilities
Buttons

45. Hydrologic Information System
Analysis, Modeling,
Decision Making
Arc Hydro
Geodatabase