Arc Hydro and Modeling

• Intrinsic Modeling – within a particular application eg Excel, ArcGIS

• Dynamic Linked Library – tightly coupled package of functions (e.g. LibHydro from HEC)

• Independent Modeling – separate hydrologic model with data exchange

Thematic Layers

supporting the Arc Hydro data model

(from Michael Zeiler“Modeling Our World”

Volume 2)

Streams

Drainage Areas

Hydrography

Channels

Terrain Surfaces

Rainfall Response

Digital Orthophotos

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

Integrating Data Inventory using a Behavioral Model

Relationships betweenobjects linked by tracing pathof water movement

Intrinsic Hydrologic Modeling

• Dr Tarboton– DEM-based

hydrologic modeling

• USGS– Stream Stats

• Mean annual flows and pollutant loads

Streamstats

http://ststdmamrl.er.usgs.gov/streamstats/expert.htm

Dynamic Linked Library

Can haveFortransubroutinesin a DLL

Muskingumflow routing

Independent Hydrologic Model

VB progam reads and writestext files

Analysis, Modeling,Decision Making

Arc Hydro Geodatabase

Visual Basic

ArcGIS

Relational D

atabase

(Access)

Excel

Interfaces to Arc Hydro Data and Models

ArcGIS Development at DHI• Extend the ArcGIS Hydro Data ModelExtend the ArcGIS Hydro Data Model

DHI TimeSeries Package• TimeSeries Package ArchitectureTimeSeries Package Architecture

TS Object

TS Editor

Timeseriesfile

DataAccess

Component

DataAccessBridges

dfs

ASCII

DB

XML

CommonFunctionality

......

TS Plot TS Tabular

TS Toolbox

Tool 1 Tool 2 Tool 3

Tool 4 Tool n......

Three basic water problems

• Too little water (Drought and water supply)

• Too much water (Flooding)• Its dirty (Water Quality)

Also have significant GIS effort on environmental issues related to water such as habitat assessment

1996 Texas Drought

• George W. Bush, (then Governor of Texas) asked: “Tell me how much water we have, how much water we’re using and how much water we need”

• State water officials did not have adequate answers

Texas Water Planning

• 1997 Texas Legislature passed Senate Bill 1 which provided for– State-wide geospatial data development

(topography, hydrography, land use, soils and orthophotos)

– Water planning in 14 regions rather than state-wide

– Assessment of water availability for all water permits

Hydrologic Cataloging Units (HUCS)

Guadalupe Basin(4 HUC’s)

Hydrologic Unit Code = 12100203

• 2015 HUC’s cover continental US• average area ~ 1 county

Water Availability in the Guadalupe Basin

Stream Gauge (14)

Water Diversion (440)

Estimate water availability at each legally permitted water diversion point based on “naturalized” flow at stream gages and the effects of other permitted diversions

Digital Elevation Model

National Elevation Dataset30m x 30m cells11,000,000 cells to cover San Marcos basin70,000,000 cells to cover Guadalupe basin

San Marcos basin

Drainage Area Delineated from the Digital Elevation Model

Arc Hydro attribute DrainArea

Estimating Naturalized Flow at Diversion Points

Qd

Qf

Ad

Af

Qd = Qf

Ad

Af

Naturalized flow record at stream gage (50 years of monthly flows)

Estimated flow record at diversion point

Length Downstream

D

F

Flow distance (D to F) = Length Downstream (D)

– Length Downstream (F)

Length Downstream (D)

Length Downstream (F)

F

D

Arc Hydro attribute LengthDown

Seepagelosses

Water Availability Modeling

Hydrologic Modeling

Water RightsAnalysis Package(WRAP)

50 yearseries ofnaturalizedmonthly flows atstream gages

GIS data for each diversion point

Letter to eachwater permitowner specifying % of permitted flow available during a drought

Completed for ~ 10,000 water permit holders, 1998-2002

Letter to eachwater permitowner specifying % of permitted flow available during a drought

Geospatial data developmentby Center for Research in Water Resources, Univ. of Texas

Texas Natural ResourcesConservation Commission

Hydrologic modeling byengineering consultants

Water Availability Assessment(completed for ~ 10,000 permit holders, 1998-2001)

Flood Hydrology and Hydraulics

ArcViewInput Data

DEM

HEC-HMSFlood

discharge

HEC-RASWatersurfaceprofiles

ArcViewFlood

plain maps

HEC-GeoHMS Hec-GeoRAS

Status of the Software

• HEC-GeoHMS ver 1.0 available from HEC for ArcView version 3 http://www.hec.usace.army.mil/software/software_distrib/geo-hms4arcview/geohmsprogram.html

• Arc Hydro terrain and watershed functions replace some but not all of HEC-GeoHMS

• HEC-GeoRAS ver 1.0 http://www.hec.usace.army.mil/software/software_distrib/geo-ras4arcview/georasprogram.html

• ESRI has developed a beta-version of GeoRAS for ArcGIS

Austin Digital Elevation Model

Waller Creek

Austin Watersheds

CRWR-PrePro (a precursor of HEC-GeoHMS)

ArcView-based preprocessorfor HEC-Hydrologic ModelingSystem (HEC-HMS)

Digital Elevation ModelStream Map

HMS Basin File

Control point locations

Soil and Land Use Maps

DEM Watersheds for Austin

Selected Watersheds and Streams

Mansfield Dam

ColoradoRiver

HMS Schematic Prepared with CRWR-PrePro

Mansfield Dam

ColoradoRiver

HMS Model of the Austin Region

HMS Results

Watershed 155 Junction 44

Flood Hydrology and Hydraulics

ArcViewInput Data

DEM

HEC-HMSFlood

discharge

HEC-RASWatersurfaceprofiles

ArcViewFlood

plain maps

HEC-GeoHMS Hec-GeoRAS

Colorado River Network

1:100,000 scale

Developed from National Hydrography Dataset

City of Austin Stream Network

Developed from 1”=100’Capco Areal photogrammetry

1:1200 scale

Stream Definition: Waller CreekAustin Watersheds with Streamsderived from Aerial Photographs

Streamlines generated by the aerial photographs are not always continuous.

Information for Correcting Stream Network

•DEM

•Contours

•Storm sewers

•Orthophotos

Resulting Corrected Stream

Subsequent steps:• Verification of corrected streams by flood hydrologists.• Running “tracer” program to connect arcs.• Burning of streams into DEM.

Waller Creek HMS Model

Flood Plain Mapping

Connecting HMS and RAS

Flood Hydrology and Hydraulics

ArcViewInput Data

DEM

HEC-HMSFlood

discharge

HEC-RASWatersurfaceprofiles

ArcViewFlood

plain maps

HEC-GeoHMS Hec-GeoRAS

HEC-RAS: BackgroundRiver Analysis System model of the U.S. Army Corps of

Engineers

Input = cross-section geometry and flow rates

Output = flood water elevations

Floodway Floodway

Left Bank Station

Flood Water Surface

Right Bank Station

Normal Water Surface

Main Channel

Cross-Section Schematic

Waller Creek

Watersheds ChannelNetwork

Points describe channel and floodway geometry

Bank station locations

Water surface elevations and floodplain boundaries

HEC-RAS: Cross-Section Description

Discharge at a Particular Cross-Section

HEC-RAS: OutputText FileGraphical

Floodplain Mapping: Plan View

3D Terrain Modeling: Ultimate Goal