1. Current Arc Hydro Functionality
Dean Djokic, Esri
Current Arc Hydro Functionality

2. What is Arc Hydro?
Extension of geodatabase model for support of water resources applications (template data model)
Originally just vector, but now raster as well
Culmination of a three year process ( ) led by D.R. Maidment through GIS in Water Resources Consortium (Arc Hydro book)
Collection of generic tools for support of Arc Hydro geodatabase design and basic water resources functions
Starting point for water resources database and application development

3. What Arc Hydro is Not!
Data set (e.g. NHD, NHDPlus, HydroSheds, AusHydro, … )
BUT you can use these data in Arc Hydro
Solution to a particular “program” problem (e.g. water allocation model, specific H&H modeling pre-/post-processing)
BUT you can use Arc Hydro tools to support those programs
E.g. water use analysis – Arc Hydro provides connectivity (surface and “structural”) and core time series data, and the computation is done in a “numerical engine”.

4. Arc Hydro Data Model

5. Basic Concepts
Define core feature classes for water resources analyses
Establish relationships between core feature classes
Use geometric network for tying pieces together
Mobilization of standard ArcGIS functionality
Custom tools for some of the attribute management
Custom tools for advanced “water resources” functionality

7. Drainage System Representations
Basins – drainage areas for water
resources management
Watersheds – subdivision of land
surface for a particular hydrologic
purpose
Catchments – subdivision of
land surface into elementary drainage areas by physical rules
Digital Elevation Model –
land surface terrain grid cells

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

9. Extending Arc Hydro Data Model

10. Extending Arc Hydro Data Model
More application specific “stuff”

11. GeoRAS Data Model Concept
Arc Hydro Data Model
ArcGIS GeoDatabase
Arc Hydro

12. Arc Hydro Channel Data Model

13. GeoRAS Data Model 2D Cross-sections (cut line)
Most of the attributes associated with cut lines
3D Cross-sections (surface line)
Just for 3D representation
A number of “profile” lines
Stream centerline
Banks
Flowpath lines
A number of tables
Manning’s N
Node

14. GeoRAS Data Model Arc Hydro inheritance Departure from Arc Hydro
HydroID
Use of HydroID for relations between the 2D cross-section representation and its derivatives (XS2DID)
Departure from Arc Hydro
Additional feature classes – both of flowline (levees, side weirs, …) and hydrography (land use, ineffective flow areas, …) types
TIN or GRID for surface definition
Additional fields

15. GeoRAS Data Model - Schema

16. Arc Hydro Tools Overview
Arc Hydro tools – selected topics
Key concepts
Global delineation – scaling issues
Tools overview

17. Arc Hydro Tools Key Concepts

18. Key Concepts
Transitions between the raster and vector worlds – integrated operations
“Relationships between objects linked by tracing path of water movement”
Raster
Network
Vector
Logical Schema
Extended Network

19. Terrain Processing Start with the terrain model
Identify drainage patterns
Identify catchments

20. Network Generation Start with the drainage pattern
Define hydro edges from drainage lines
Generate junctions at confluences
Build the geometric network

21. Connecting Catchments to Junctions
Start with the catchments
Identify drainage points
Link drainage points to junctions

22. Extended (Hydrologic) Network
Combination of hydro network and drainage areas connected through junctions.
Allows tracing through network and selection on drainage areas

23. Node-Link Schematization (1)
Start with the catchments
Find centroids
Continue with drainage lines
Find confluences
Connect nodes

24. Node-Link Schematization (2)
Transition from geo representation to logical representation
Support for various modeling efforts

25. Global Delineation (1)
Deal with scalability issues related to DEM size (large areas/high resolution)
Approach
Combine raster analysis on individual areas (any size) that are manageable from DEM point of view, and network analysis between the individual areas
Example – 10 HUC8 cataloging units

26. Global Delineation (2)
Start with well defined database design structure
Apply it independently to all DEM processing units
HydroID does not have to be unique across GDBs

27. Global Delineation (3) Construct the extended network
Some work involved for HUC 8 processing units

28. Global Delineation (4) Define the point Delineate local watershed
Trace upstream
Identify contributing catchements
Merge shapes and store

29. Global Delineation (5)
Currently area and few topographic characteristics are computed – other parameters of interest are being added
Aggregation types – additive, min, max, special
Potentially interesting issues
Geometry size and complexity
Speed in aggregation (preprocessing option)

30. Arc Hydro Tools Overview

31. Arc Hydro Tools Overview (1)
A set of tools that “exercises” the Arc Hydro model
Integral with standard ArcGIS functionality
Key field (property) management.
HydroID & related IDs
Length/Area measures
Core functions
DEM-based watershed delineation
Network generation
Attribute and network tracing and summary operations

32. Arc Hydro Tools Overview (2)
Distribution (version 1.3, 1.4, 2.0 beta)
A toolbar with packaged menus and buttons
A toolbox with selected functions
Supporting documentation/help
ArcGIS 8.3 and ArcGIS 9/9.1/9.2/9.3 versions, 2.0 version for ArcGIS 10

33. Walk-through
Global delineation (accumulation of characteristics as well)
Local delineation
Trace on the network using standard network tracing techniques
Trace using NextDownID
Accumulate
Schematization

34. Many Aspects of Arc Hydro
Database design
Marketing
Tools
Application
“Standard”
Development environment
Saxe, John Godfrey, 1963, “The Blind Man and the elephant”, New York: Whittlesley House
Elephant illustration ©2002 Jason Hunt

35. Applying Arc Hydro
Extension of Arc Hydro data model for support of water resources applications
Addition of features and feature classes
Addition of functionality (tools)
Various entities
ESRI
CRWR (SFWMD, SARA, WAM, …)
Other (USGS, OMNR CA, SJRWMD, PBS&J, …)

36. Applying Arc Hydro Highlighted implementation

37. Arc Hydro Customization at SWFWMD (1)
District Function
Water supply
Flood protection
Water quality
Natural systems

38. Arc Hydro Customization at SWFWMD (2)
Arc Hydro data model extension
GWIS (Geographic Watershed Information System)
Modeling support (ICPR)
Deranged terrain processing
Management of pitted terrains
Structures
Hydraulic element points
Hydraulic subelements
Tools
Arc Hydro geodatabase import
Geoprocessing

39. Pitted Terrain Analysis
Prescreen & Evaluate Sinks - Select Based on User Thresholds
Delineate Catchments Draining into Selected Sinks (where “IsSink” = 1)

40. Surface Connectivity Drainage Points within Catchments HydroJunctions
HydroEdges
(Low Point of Basin or Low Point of Boundary)
(Boundary Link Flowlines)

41. Field Acquisition of Hydraulic Features
Arc Hydro

42. Hydraulic Element Points
Same HydroCode assigned to Hydrojunction & Subelements (i.e _003)
HydroJunction
Subelement 2
Subelement 1
TR = Top of Road UIC = Upstream Invert of Culvert,
GR = Natural Ground ERM = Elevation Reference Mark
Arc Hydro

43. Hierarchy of Hydraulic Features
HydroJunction / HydroEdge
General Location & Type
Sub Elements
Hydraulic Structure Information Tables
Hydraulic Element Points
Specific Location (X, Y) & Elevation (Z)
Arc Hydro

44. ID Assignment at Culvert Location
HydraulicElementPoint
PointType = UIC
JunctionID = 7
SubElementID = 117
PointType = DIC
SubElementID = 118
HydroJunction
HydroID = 7
HydroID = 117
HydroID = 118
SubElement: Pipe_Barrel
HydroID = 117
JunctionID = 7
HydroID = 118
Each Culvert (Barrel) is a Subelement with a Unique HydroID (117, 118)
The HydroJunction represents the general location of the SubElements
The SubElements are related to the HydroJunction through the JunctionID
The SubElements are made up of HydraulicElementPoints (UIC, DIC, etc.)
HydraulicElementPoints are related to the SubElements through the SubElementID
Arc Hydro

45. Sub Element Tables
Arc Hydro

46. Connect HydroJunction tool
Hydraulic Element Points identify a culvert location
User manually places HydroJunction
(and snaps it to Drainage Boundary)
Tool connects HydroJunction
(and creates Structure Link)

47. Applying Arc Hydro Various implementations

48. River Hydraulics in ArcGIS 9 (HEC-GeoRAS)
Work with HEC on developing GeoRAS solution for ArcGIS platform.
Fully support RAS 4.0 spatial functionality
New (improved) UI
Additional spatial data input
Levees, ineffective flow areas, …
Terrain definition by TIN and GRID
Multi-TIN/GRID terrain representation
XML data I/O
Released as HEC “product”
Extension of Arc Hydro data model

49. River Hydrology (HEC-GeoHMS)
Work with HEC on developing GeoHMS solution for ArcGIS platform.
Fully support GeoHMS 1.1 functionality
New (improved) UI
Additional characteristics
XML data I/O
Will be released as HEC “product”
Extension of Arc Hydro data model
Status
Beta completed
In works: HMS 3 support (ModClark)

50. Map2Map (rainfall to floodplain)
FLOODPLAIN MAP
Flood map
as output
Model for
flood flow
Model
for flood
depth
HMS
Nexrad rainfall map as input

51. StreamStats (USGS)
Implementation of USGS regression equations for flow computations at ungaged locations
Web based application (and desktop)
Status – many States completed, work on several others in progress
Additional work contracted
Full implementation in Arc Hydro – all new GIS functionality is rolled-into Arc Hydro
ArcGIS Server implementation

52. So.Cal Fires Debris Flow Predictions
Implement USGS debris flow prediction model within ArcGIS environment
Peak flow
Probability of occurrence
Custom regression calculator
Built on top of Arc Hydro and StreamStats functionality for watershed delineation and characterization
Generalization of characteristics extraction
Export to Excel
New functionality rolled-into Arc Hydro

53. So.Cal Fires Debris Flow Predictions

54. Discussion