Geographically Integrated Hydrologic Modeling Systems
Interface
data models
GIS
Model 1
Geo
Database
Arc Hydro
data model
Model 2
Model 3
Arc Hydro — Hydrography
Arc Hydro — Hydrology
Geographic Data Model
• Conceptual Model – a set of concepts that describe
a subject and allow reasoning about it
• Mathematical Model – a conceptual model
expressed in symbols and equations
• Data Model – a conceptual model expressed in a
data structure (Logical data model, physical data
model)
• Geographic Data Model – a data model expressed
in a GIS database
Data Model
based on
Inventory of
data layers
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.”
R.M. Hirsch, USGS
Arc Hydro Components
Drainage System
Hydro Network
Flow
Time
Time Series
Hydrography
Channel System
Arc Hydro Framework Input Data
Watersheds
Waterbody
Streams
Hydro Points
Feature
Arc Hydro Framework
Data Model
Waterbody
HydroPoint
HydroID
HydroCode
FType
Name
JunctionID
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ComplexEdgeFeature
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HydroID
HydroCode
FType
Name
AreaSqKm
JunctionID
HydroID
HydroCode
DrainID
AreaSqKm
JunctionID
NextDownID
*
*
!(
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*
Watershed
SimpleJunctionFeature
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HydroEdge
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HydroID
HydroCode
ReachCode
Name
LengthKm
LengthDown
FlowDir
FType
EdgeType
Enabled
EdgeType
Flowline
Shoreline
1
HydroNetwork
HydroJunction
HydroID
HydroCode
NextDownID
LengthDown
DrainArea
FType
Enabled
AncillaryRole
1
Arc Hydro Framework For South Florida
Basins
Waterbody
(NHD)
Hydro Points
Hydro Network
(NHD)
Nexrad Radar Rainfall Map
Extended Arc Hydro Framework
for South Florida
HydroPeriod
Analysis
Extended
Arc Hydro
Operations
Decision
Support
System
Arc Hydro
Framework
Regional
Simulation
Model
Framework for
South Florida
Flood Modeling
and
Management
1. Define the Data Themes in the
Core Model
• Hydrographic lines
• Water bodies
• Drainage areas
• Structures
• Gages
+ ……..
Who will produce and verify these data?
Will National Hydrography Dataset be used?
•
•
•
•
•
2. Define the ODSS GIS
Framework
Select the ODSS waterbodies
and structures from the core
GIS framework
Integrate water control units
in GIS
Define drainage area for each
WCU
Build interface data model for
ODSS
Build tools for 2-way linkage
between ArcGIS and ODSS
Arc Hydro UML for ODSS
WCU Schematic Link
Water Control Network
WCU Schematic Node
Extended Arc Hydro Framework
1
1
HydroJunction
1
1..*
Water body
1..*
1
Hydro
HydroEdge
network
Subtypes
Canal
Segment
Lake
Subtypes
Uncontrolled Controlled
Junction
Junction
Basin
Tidal
Marsh
1..*
MonitoringPoint
1
Structure
1..*
•
•
•
•
•
3. Define the Flood Modeling
Framework
Define drainage areas,
channels and control
structures to be included
Define flood simulation
model(s) to be used
Design ArcGIS interface data
model, if necessary
Populate models with GIS
data (Watershed analyst)
Build tools for 2-way linkage
between ArcGIS and Flood
Models, if necessary
4. Define the RSM GIS Framework
• Generalize GIS data needed
for RSM (linear referencing
and event themes)
• Generate triangular mesh
• Represent canal segments and
pseudocells in GIS
• Define ArcGIS interface data
model for RSM
• Build tools for 2-way linkage
between ArcGIS and RSM
5. Define GIS Functionality for
Hydroperiod
• Define conceptual
framework
• Convert to mathematical
form
• Define data structures
needed
• Build tools to execute
model
• Check against observed
points to verify analysis
• Train the District staff!
6. Build the District Arc Hydro
Framework
• Build the
HydroNetwork
• Connect the drainage
areas
• Connect the
structures and
monitoring points
• Integrate other
themes (e.g. District
RSM mesh?)
7. Define the Water Inputs
• Connect to the Nexrad
data
• Connect to dbHydro
for gage information
• Satellite information?
• Climate information?
• Water quality?
8. Build Information Flows Among
Applications
HydroPeriod
Analysis
Extended
Arc Hydro
Operations
Decision
Support
System
Arc Hydro
Framework
Regional
Simulation
Model
Framework for
South Florida
Flood Modeling
and
Management
Regional Storm Water
Modeling Program and Master
Plan for San Antonio
Regional Watershed Modeling
Master Plan Goals
• Develop new or incorporate existing hydrology,
hydraulic and water quality models (“Bring the models
together”)
• Provide GIS-based interfaces for models
• Provide for maintenance of models and geospatial data
• Develop standards for modeling and geospatial data
• Regional Watershed Modeling System to assist in:
– flood mitigation planning
– capital project prioritization
San Antonio Regional Watershed Modeling System
Geospatial Data:
City, County
SARA, other
Rainfall Data:
Rain gages
Nexrad
Floodplain
Management
Modeling
System
Calibration Data:
Flows
Water Quality
Capital
Water quality
Improvement
planning
Planning
Integrated
Flood
Regional Water
Forecasting
Resources planning
Arc Hydro and HEC-HMS
HEC-HMS
Hydrologic
Model
Arc Hydro
Schematic
Network
Calculates
Flows
Arc Hydro and HEC-RAS
Arc Hydro
Channel
Cross Sections
HEC-RAS
Hydraulic
Model
Calculates
Water Surface
Elevations
Flow Change Points
Models communicate with
one another through Arc Hydro
at designated points
Nexrad Map to Flood Map in
FLO
Model Builder ODP
Flood map
as output
LAIN
MAP
Model for
flood flow
HMS
Nexrad map as input
Model
for flood
depth
Hydrologic Modeling within
ArcGIS
• Reverse engineer the parameter values
from calibrated hydrologic simulation
models into the interface data model
• LibHydro – a library of hydrologic
processing functions callable as a dll
• Schematic network processor to
execute functions in the right order
Schematic Network
• Standard Arc Hydro
data structure
– Schematic Links
– Schematic Nodes
• Type 1 Nodes and
Links for Watersheds
• Type 2 Nodes and
Links for Streams
• Type 3 for …..
Schematic Network Processes
• Node processes
– Rainfall-runoff and
pollutant loads on
watersheds
– Summing flows or loads on
streams
– Water quality in water
bodies
• Link processes
– Routing flows in streams
– Pollutant losses in streams
LibHydro
• A Fortran subroutine library of hydrologic
processes developed from HEC-1
• Packaged in LibHydro.DLL for operation
under Visual Basic
• Transforms input time series to output time
series
• More details on GISHydro 2003 CD
Excess Calculation
• Initial Loss and Constant Loss Rate function
Pick up a watershed
HydroID = 2346
ImperviousAreaRatio = 0.0001
InitialLoss = 1.6 (mm)
ConstantLossRate = 0.38 (mm)
Excess calculation in Llano basin
Period: 7/21/97 – 7/23/97 (3 days)
Time Interval: 15 minutes
Time step: 4 * 24(hour) * 3(days) = 288
Precipitation, Excess
(mm/hr)
Simulation
10
8
Precip (mm)
6
Excess (mm)
4
2
0
7/21
7/22
7/23
Date
7/24
Runoff Calculation
• Snyder Unit Hydrograph
Pick up a watershed
Watershed area: 266.5 (km2)
SnyderCp: 0.8
SnyderTp: 5.58 (hr)
Hydrograph for Llano Basin
100
8
80
Runoff (m3/s)
6
60
Precip (mm)
4
Excess (mm)
40
0
0
7/
23
20
7/
22
2
7/
21
Precipitation,
Excess (mm/hr)
Period: 7/21/97 – 7/23/97 (3 days)
Time Interval: 15 minutes
10
date
Runoff (m3/s)
Simulation
Outflow Calculation
• Add Baseflow module
• Outflow = runoff + baseflow
• Recession Ratio = 0.95, Threshold value = 2 (m3/s)
Hydrograph for Llano Basin
Runoff (m3/s)
80
6
Outflow(m3/s)
60
4
Precip (mm)
40
Excess (mm)
2
7/
23
0
7/
22
0
20
date
Runoff (m3/s)
100
8
7/
21
Precipitation,
Excess (mm/hr)
10
Looping Through the Schematic Network
Receive
Process
Get
Upstream
Features
Upstream
HydroIDs HydroIDs
HydroID
Topology
Collection
Feature,
Values
Get
Upstream
Values
Process
Upstream
Values
Values
Processed
Value
Value
Collection
HydroID,
New Value
Update
Value
Collection
See GISHydro2003 CD for details
Process
Value to
Pass
Feature,
Value
Processed
Value
Pass
Process
Schematic Network Process
Implementation
Geodatabase
ArcToolbox
Script Tool
(ProcessSchematic)
GIS
Script
(ProcSchematic.vbs)
DLL
(MBSchematic.dll)
Script and DLLs
Process DLL 1
Process DLL n
Strengths of ArcGIS for
Modeling
• Integration with the COM environment, use
of Visual Basic, and accessibility of models
through dlls is great step forward
• Network topology a big help for water
resources networks
• Geodatabase design process is important
for modeling system architecture
• Model Builder is great for handling work
flow sequences
Limitations of ArcGIS for
Modeling
• No data model and tools for time series in core
software
• Graph plotting is inadequate for displaying time
series
• Relationships are critical in geodatabase design
but can’t be created in ArcView – separate toolkits
for ArcInfo and ArcView implementation of
modeling systems?
• No scheme for scenario management
Overall Assessment
• Geographic
framework: solid
• Model connections:
good architecture,
needs development
• Time series: being
improved with current
research
Hydrologic Information System