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Geographically Integrated Hydrologic Modeling Systems. GIS. Interface data models. Model 1. Geo Database. Arc Hydro data model. Model 2. Model 3. Arc Hydro — Hydro graphy. Arc Hydro — Hydro logy. Geographic Data Model.
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Geographically Integrated Hydrologic Modeling Systems GIS Interfacedata models Model 1 Geo Database Arc Hydro data model Model 2 Model 3
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 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
Drainage System Hydro Network Flow Time Time Series Hydrography Channel System Arc Hydro Components
Arc Hydro Framework Input Data Watersheds Waterbody Streams Hydro Points
Arc Hydro Framework Data Model
Arc Hydro Framework For South Florida Basins Waterbody (NHD) Hydro Points Hydro Network (NHD)
Operations Decision Support System HydroPeriod Analysis Extended Arc Hydro Arc Hydro Framework Flood Modeling and Management Regional SimulationModel Framework for South Florida Extended Arc Hydro Framework for South Florida
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..* 1 1 Water body HydroJunction 1..* 1 Hydro network HydroEdge Subtypes Uncontrolled Junction Controlled Junction Subtypes 1 Basin Tidal Canal Segment Lake Marsh 1..* MonitoringPoint 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?
Operations Decision Support System HydroPeriod Analysis Extended Arc Hydro Arc Hydro Framework Flood Modeling and Management Regional SimulationModel Framework for South Florida 8. Build Information Flows Among Applications
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 Modeling System Rainfall Data: Rain gages Nexrad Calibration Data: Flows Water Quality Floodplain Management Capital Improvement Planning Water quality planning Integrated Regional Water Resources planning Flood Forecasting
Arc Hydro and HEC-HMS HEC-HMS Hydrologic Model Arc Hydro Schematic Network Calculates Flows
Arc Hydro and HEC-RAS HEC-RAS Hydraulic Model Calculates Water Surface Elevations Arc Hydro Channel Cross Sections
Flow Change Points Models communicate with one another through Arc Hydro at designated points
FLOODPLAIN MAP Nexrad Map to Flood Map in Model Builder Flood map as output Model for flood flow HMS Model for flood depth Nexrad map as input
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
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
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 Schematic Network Processes
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) Simulation Period: 7/21/97 – 7/23/97 (3 days) Time Interval: 15 minutes Time step: 4 * 24(hour) * 3(days) = 288
Runoff Calculation • Snyder Unit Hydrograph Pick up a watershed Watershed area: 266.5 (km2) SnyderCp: 0.8 SnyderTp: 5.58 (hr) Simulation Period: 7/21/97 – 7/23/97 (3 days) Time Interval: 15 minutes
Outflow Calculation • Add Baseflow module • Outflow = runoff + baseflow • Recession Ratio = 0.95, Threshold value = 2 (m3/s)
Receive Process Feature, Values Get Upstream Features Get Upstream Values Process Upstream Values Processed Value Upstream HydroIDs HydroID HydroIDs Values Topology Collection Value Collection HydroID, New Value Update Value Collection Process Value to Pass Processed Value Pass Process Feature, Value Looping Through the Schematic Network See GISHydro2003 CD for details
Schematic Network Process Implementation Geodatabase GIS Script (ProcSchematic.vbs) ArcToolbox Script Tool (ProcessSchematic) 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