Arc Hydro: GIS for Water Resources David R. Maidment University of Texas at Austin Arc Hydro –Culmination of a 3-yr effort –GIS in Water Resources Consortium –Customization of ArcGIS for water resources –Arc Hydro toolset and application framework

GIS in Water Resources Consortium Bringing together these two communities by using a common geospatial data model GIS Water Resources CRWR

Geodatabase MS Access Oracle SQL Server Informix DB2 Feature IFeature : IRow IFeature IFeatureBuffer IFeatureBuffer : IRowBuffer IFeatureDraw IFeatureDraw : IUnknown ArcGIS Introduces A new geographic data model A new geographic database –Stored in an Relational Database (Geodatabase) ArcObjects –Component Object Model (COM) objects that access geographic data –Works like MS Word, Excel, Powerpoint, ….

What is Arc Hydro? An data infrastructure for storing and integrating hydro data within ArcGIS –A set of hydro objects built on top of ArcObjects –A set of standardized attributes –A vocabulary for describing data (glossary) –A toolset for implementing the data model

Geodatabase Model Feature Geographic Object Row in DBMS Table Geodatabase Collection of FeatureDataSets Like a workspace FeatureDataSet Collection of FeatureClasses Like a Coverage FeatureClass Collection of Features Like a Coverage FeatureClass

Features are geographic objects stored in relational database tables Feature location is an attribute of type shape –Point, Multipoint, Line, Polygon –Attributes and geometry are stored together not in separate files as in Arc Info 7 and ArcView 3 Features Feature (row) ShapeOID 524X,Y,Z,M,... Stream Type Channel... FeatureClass (table)

Feature DataSets A holder for a set of feature classes having a common coordinate system and spatial extentGeoDatabase FeatureClass Feature (row) ShapeOID 524X,Y,Z,M,... Stream Type Channel... FeatureClass (table) Object Class FeatureDataset

Extensible Data Model Stream Basin Feature GageConfluence ComplexEdge SimpleJunction NetworkFeature JunctionFeature EdgeFeature Row Measurement

Flow Time Time Series HydrographyHydro Network Channel System Drainage System Arc Hydro Components

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

Arc Hydro Data Model Hydrography Hydrology

Streams Drainage Areas Hydrography Channels Terrain Surfaces Rainfall Response Digital Orthophotos Data Model Based on Inventory

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.

Integrating Data Inventory using a Behavioral Model Relationships between objects linked by tracing path of water movement

Arc Hydro Framework dataset for USA at 1:500,000 scale Built from USGS and National Weather Service data MonitoringPoints are USGS stream gaging stations Arc Hydro USA

Hydro response units are based on the land use map Arc Hydro geodatabase for City of Austin

Streams WatershedsWaterbody Monitoring Points Arc Hydro Framework Input Data

Arc Hydro Framework

Arc Hydro Framework Dataset for the Guadalupe Basin

HydroNetwork through Canyon Lake Generic Junction (for topological connection of edges) Flowlines through water body

HydroJunction has Waterbody Relationship

National Hydro Data Programs National Elevation Dataset (NED) National Hydrography Dataset (NHD) Watershed Boundary DatasetElevation Derivatives for National Application (EDNA)

Hydrologic Cataloging Units (HUCS) Guadalupe Basin (4 HUC’s) H ydrologic U nit C ode = HUC’s cover continental US average area ~ 1 county

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

Regional Analysis HydroNetwork to provide connectivity of flow through large regions Digital elevation model for terrain analysis within basins

Scales of representation of Drainage Systems Basins – drainage areas for water resources management Catchments – subdivision of Basin into elementary drainage areas by physical rules Digital Elevation Model – land surface terrain grid cells Watersheds – subdivision of Basin for a particular hydrologic purpose

Catchments, DrainageLines and DrainagePoints

Catchments Subdivided at Watershed Outlet

Area to Area Navigation

EDNA Catchments Average area = 7.5 km 2 Designed for remapping of Nexrad data onto drainage units

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

Intrinsic Hydrologic Modeling Dr Tarboton –DEM-based hydrologic modeling Mean annual flows and pollutant loads USGS –Stream Stats Streamstats

Analysis, Modeling, Decision Making Arc Hydro Geodatabase Visual Basic ArcGIS Relational Database (Access) Excel Interfaces to Arc Hydro Data and Models

Dynamic Linked Library Can have Fortran subroutines in a DLL Muskingum flow routing

Independent Hydrologic Model VB progam reads and writes text files

Flood Hydrology and Hydraulics ArcView Input Data DEM HEC-HMS Flood discharge HEC-RAS Water surface profiles ArcView Flood plain maps HEC-GeoHMSHec-GeoRAS

Austin Digital Elevation Model Waller Creek

Austin Watersheds

DEM Watersheds for Austin

Selected Watersheds and Streams Mansfield Dam Colorado River

HMS Schematic Prepared with HEC-GeoHMS Mansfield Dam Colorado River

HMS Model of the Austin Region

HMS Results Watershed 155Junction 44

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 Creek Austin Watersheds with Streams derived from Aerial Photographs Streamlines generated by the aerial photographs are not always continuous.

Waller Creek HMS Model

Connecting HMS and RAS Hydrology Model defines flows (HMS) Hydraulic Model defines water surface elevations (RAS)

Flood Hydrology and Hydraulics ArcView Input Data DEM HEC-HMS Flood discharge HEC-RAS Water surface profiles ArcView Flood plain maps HEC-GeoHMSHec-GeoRAS

Flood Plain Mapping

HEC-RAS: Background River Analysis System model of the U.S. Army Corps of Engineers Input = cross-section geometry and flow rates Output = flood water elevations Cross-Section Schematic

Waller Creek Watersheds Channel Network

HEC-RAS: Output Text File Graphical

Floodplain Mapping: Plan View

3D Terrain Modeling: Ultimate Goal

What software do you need? ArcView 8.2 –Viewing, querying existing geodatabases –Editing feature classes and adding data Spatial Analyst for ArcGIS –To operate the raster tools in Arc Hydro ArcInfo 8.2 –To build geometric networks and create new relationships

Arc Hydro Tools Version 1.0 Raster processing –DEM processing –Watershed delineation Vector processing –Arc Hydro attributes –Network analysis Time Series and Application Utilities Buttons

Status of the HEC-related Software HEC-GeoHMS ver 1.0 available from HEC for ArcView version 3 (version 1.1 to be released soon) hms4arcview/geohmsprogram.html hms4arcview/geohmsprogram.html Arc Hydro terrain and watershed functions replace some but not all of HEC-GeoHMS HEC-GeoRAS ver ras4arcview/georasprogram.html ras4arcview/georasprogram.html ESRI has developed a beta-version of GeoRAS for ArcGIS (integrated with Arc Hydro)

Tools (Dean Djokic)

TSDateTime FeatureID TSType TSValue Arc Hydro Time Series Object

National Water Information System Web access to USGS water resources data Arc Hydro NWIS data retrieval tool

Space Historical daily mean discharge Streamflow statistics Real Time data Streamflow Information in Space and Time Time At Gages Anywhere on a Stream Future PossibilitiesCurrent Streamstats

HydroID and HydroCode

Retrieving NWIS Data Select Gage Layer Enter Period of Record

Streamflow Time Series Arc Hydro Time Series Table

Time Series Extracted to Excel (In Excel, use Data/Get External Data to query Geodatabase) Geodatabase view Excel view

HRAP Cells for Nexrad Data Average area = 14.5 km 2

Coupling Spatial and Temporal Data 1 hour Nexrad Rainfall on the Guadalupe Basin October 13, 2001

Water Balance in the Landscape Atmospheric Water Soil WaterSurface Water Groundwater Precipitation Evaporation Runoff Recharge Baseflow

EDNA Catchments Average area = 7.5 km 2

Intersection of Nexrad and Catchments Atmospheric Water Soil Water Surface Water Surface Water Balance

Modflow Groundwater Cells Average area = 2.6 km 2 Modflow Model of the Edwards-Trinity aquifer

Intersection of Nexrad and Modflow Cells Atmospheric Water Groundwater Balance

Intersection of Nexrad, Catchments and Modflow Atmospheric Water Soil WaterSurface Water Groundwater

DHI Tools for TimeSeries Management and Analysis –Manages TimeSeries Data at the GeoDatabase level An ArcHydro based GeoDatabase Import from a variety of formats (DHI, USGS, text file) Query for Data Types –Manages TimeSeries Data for Features Plot Statistics Query for Time Periods –Performs Calculations and Analysis Mean Area Rainfall –Thematic groups of time series Water Users (Industrial, Irrigators) Data Types (Rainfall, Evaporation)

Import TimeSeries USGS USGS Bridge HEC Bridge dfs0 Bridge Geo Database HEC dfs0 Slides provided by Michael Blongewicz, DHI Water and Environment, Denmark

Manage TimeSeries Data within ArcMap

At the GeoDatabase level

At the Feature level

Feature based; update Properties, plot, statistics

Geoprocessing and Terrain Analysis (Steve Kopp)

River Modeling  River hydraulic modeling provides a tool to study and gain understanding of hydraulic flow phenomena  Topographic data describe the geometry of the simulated river system and permit the establishment of model topology  HEC-RAS, MIKE 11 hydraulic models require channel information for model development

River Morphology

Flood Inundation

Floodplain Delineation

Channel and Cross-Section Direction of Flow Cross-Section Channel

ProfileLines Types 1- Thalweg 2- LeftBank 3- RightBank 4- LeftFloodLine 5- RightFloodLine ProfileLines and CrossSections are linked through Channel_ID

TIN as a source of cross-sections

CrossSections

Data for channels Bathymetry data for channels mainly include points with (x,y,z) attributes. Data can be collected using –Traditional methods (surveying) –Depth sounder (using a boat) –LIDAR ( Light Detection and Ranging) –SAR (Synthetic Aperture Radar), etc.

Data analysis (Research of Venkatesh Merwade, CRWR) Start with points Create surface from points Centerline/Thalweg Cross-sections ProfileLines Extract all the necessary information How do we do this…….

Defining a Thalweg Input Step 1Step 3Step 4 Output User defines an arbitrary centerline over the measurement points Thalweg tool creates a surface using the measurement points Normals are drawn at each vertex of the centerline to locate deepest points All the deepest points replace the vertices of the old centerline Final result is a 3D polyline defining the thalweg Densify the initial centerline to get more points Old vertices New vertices Step 2

Measure in ArcGIS A PolylineMZ can store m and z at each vertex along with x and y coordinates

Coordinate Transformation m is measure along the centerline r is distance across the river from the centerline Sinuous river becomes straight when transformed into (m,r) co-ordinates.

A “straightened” channel! x y m r Coordinates measured along and across the channel Northing and Easting Coordinates

Surface in transformed co-ordiantes Sinuous river Profile line and cross-sections Straightened river

Straightened channel as a 3D Fishnet

Transform the data back to x,y coordinates Original river in X,Y Profile lines and cross-sections in (x,y) created using FishNet in (m,r).

Profile Lines and Cross Sections in 3D Bird’s eye view!

Breaklines Profile lines are actually breaklines but they are created using a surface. Need a methodology to create breaklines before generating a surface (especially TIN) in order to handle false dams.

Measurement pointsSurface Thalweg/CenterlineCross-sections ProfileLines Fishnet GIS for River Channels Develop generic ways to create all the channel features from measurement points. This task is almost finished.

Cross-sections comparison Cross-section without breaklinesCross-section with breaklines Both cross-sections are created using a TIN.

Channel Movie The channel of the Brazos River near Sealy, TX. Bathymetry is recorded using a depth sounder from a boat. Land surface is represented using NED and DOQ