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

2. GIS Preprocessors for Hydrologic Models
Interface
Model 1
Database
Model 2
Model 3

3. Connecting Arc Hydro and Hydrologic Models
GIS
Interface data models
HMS
Geo
Database
Arc Hydro
data model
RAS
WRAP

4. Nexrad Map to Flood Map in Model Builder
FLOODPLAIN MAP
Flood map
as output
Model for
flood flow
HMS
Model
for flood
depth
Nexrad map as input

5. Arc Hydro Implementation Projects
LCRA
Arc Hydro geodatabase for Llano Basin
Interface geodatabase model for HEC-HMS
Experiments with LibHydro on Llano Basin
SARA
Arc Hydro geodatabase for Salado and Rosillo Creeks
Interface geodatabase model for RAS (partly)
“Map to map” application using Model Builder

6. 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

7. Excess Calculation Initial Loss and Constant Loss Rate function
Pick up a watershed
HydroID = 2346
ImperviousAreaRatio =
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

8. Runoff Calculation Snyder Unit Hydrograph Pick up a watershed
Watershed area: (km2)
SnyderCp: 0.8
SnyderTp: 5.58 (hr)
Simulation
Period: 7/21/97 – 7/23/97 (3 days)
Time Interval: 15 minutes

9. Outflow Calculation Add Baseflow module Outflow = runoff + baseflow
Recession Ratio = 0.95, Threshold value = 2 (m3/s)

11. 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 …..

12. 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

13. Looping Through the Schematic Network
Get Upstream Features
Get Upstream Values
Process Upstream Values
Process Value to Pass
Update Value Collection
Topology Collection
Value Collection
Receive
Process
HydroID
Upstream HydroIDs
HydroIDs
Values
Feature, Values
Feature, Value
Processed Value
Pass
HydroID, New Value
Here’s a summary of the “for each feature” loop.
See GISHydro2003 CD for details

14. 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

15. Regional Flood Control, Drainage, and Storm Water Management Program
Partners in San Antonio
Good morning.
It’s my pleasure to share with you an example of regional cooperation within Bexar County.

16. San Antonio River Basin

17. Interlocal Agreement Coverage Area Salado Leon Cibilo Creek San
Watershed
Area
Sq. Mi.
Population
Cibolo Creek
204
97,000
Leon Creek
235
278,000
Medina River
290
83,000
Salado Creek
222
349,000
San Antonio River
270
582,000
Salado
Leon
Cibilo
Creek
Bexar County (COUNTY), the City of San Antonio (COSA), and the San Antonio River Authority (SARA) are working together to create and integrated system to most effectively address flood control and water quality issues within the five watersheds and the multiple jurisdictions that comprise the San Antonio River Basin in Bexar County. The intent of this cooperative and collaborative effort is to create uniform tools, techniques, and guidelines for use by all the governmental entities within Bexar County in order to base storm water management decisions upon proven science, reliable data, uniform standards and criteria.
Population: 1.4 million
Area: City – 425 square miles
City with ETJ – 1200 square miles
County – 1400 square miles
The region is defined as Bexar County.
San
Antonio
River
Medina

19. Prototype Application
Rosillo/Salado Creek watershed
Arc Hydro geodatabase developed for full Salado Creek watershed
TAMU and UT developed Arc Hydro-compliant, model-specific geodatabases for Rosillo Creek
HEC-HMS
HEC-RAS
Utilizing interfaces currently under development (PrePro2000/HEC-GeoHMS, HEC-GeoRAS)
Successfully linked the Rosillo Creek and Salado Creek models for HEC-HMS and HEC-RAS applications

20. Flood Alert / Flood Forecasting Flood Modeling and Forecasting
Coordination has begun with NWS River Forecast Center
Update river forecasting to 1 hour (currently 6 hours)
Evaluating flash flood forecasting for smaller watersheds
Evaluating integration of NEXRAD data into the proposed system