Arc Hydro: GIS for Water Resources Arc Hydro –Networks and the Framework –Drainage systems –Channels –Time Series –Modeling David R. Maidment, University of Texas at Austin

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 equations Data Model – a conceptual model expressed in a data structure Geographic Data Model – a data model for describing and reasoning about the world

Hydrologic Information System Hydrologic Modeling Arc Hydro Geodatabase

GIS in Water Resources Consortium Bringing together these two communities by using a common geospatial data model Arc Hydro design took 3 years from GIS CRWR Water Resources

Flow Time Time Series HydrographyHydro Network Channel System Drainage System Arc Hydro Data Model

ArcGIS 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

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

Streams WatershedsWaterbody HydroPoints Arc Hydro Framework Input Data

Arc Hydro Framework

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

Arc Hydro Applied to an Urban Subdivision Building lot Grassy swale Storm sewer

Arc Hydro Framework Dataset for the Guadalupe Basin

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

Network Tracing Upstream Tracing Downstream Tracing

HydroJunction has Waterbody Relationship

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

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

Catchments, DrainageLines and DrainagePoints

Catchments Subdivided at Watershed Outlet

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

Guadalupe Network Study area only 1.4 km!

1/2 meter Digital Ortho Photography Study Area (Guadalupe river near Seguin, TX)

Boat setup for data collection

Accoustic Doppler Current Profiler Provides full profiles of water velocity and direction in the ocean, rivers, and lakes. Also used for discharge, scour and river bed topography.

The electronic depth sounder operates in a similar way to radar It sends out an electronic pulse which echoes back from the bed. The echo is timed electronically and transposed into a reading of the depth of water. Depth Sounder (Echo Sounder)

Differential GPS: Bank to Boat GPS gives the location of each point collected in terms of latitude and longitude. Two locations for differential GPS.

Channel Data Each point has (x,y,z)

Interpolation Points are interpolated in ArcMap to produce a continuous surface.

FishNet (2D) FishNet is generated in ArcMap using FishNet tool in ArcGIS.

3D Visualization in ArcScene

Centerline Define the centerline such that it joins the center of flow (area) at each cross section.

Measure in ArcGIS A PolylineM can store m-values at each vertex along with x and y coordinates. Measures are assigned in meters

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.

Coordinate Transformation Sinuous river Profile line and cross-sections Straightened river

Straightened River in 3D

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!

Integrated Terrain Database Currently Being Developed by ESRI for ArcGIS

Traditional TIN Terrain Data stored in the geodatabase as points, lines and polygons Integrated Terrain Database Easy to visualize and analyze

30m DEM Data sources for Terrain Input data include everything from coarse DEMs to massive measurement points (eg. Channel data, LIDAR) Detail channel data Input data Terrain

Terrain data view in ArcCatalog Measurement Points Channel Boundary Profile Lines Terrain Points to build terrain All data (points, lines and polygons) are stored in the standard GeoDatabase as featureclasses.

Points Lines Surface How does it work Generates required information based on the input data so that subsets from the big database can be retrieved quickly Not all measurement points are used to generate final surface

Visualization and Analysis TINs are built on fly for visualization and analyses as the user zooms or pans around the display. Massive datasets are easy to handle & data processing is fast.

Summary Ability to store vector based terrain data in the geodatabase. Huge datasets are easy to handle and quick to analyze TINs are be built on fly at different scales (eg. Coarse TIN using little data for entire basin and detailed TIN for channel using measurement points)

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

TSDateTime FeatureID TSType TSValue Arc Hydro Time Series Object

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 Nexard 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

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

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

Intersection of Nexrad and Modflow Cells Atmospheric Water Groundwater Balance

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

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

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

Independent Hydrologic Model VB progam reads and writes text files

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

Analysis, Modeling, Decision Making Arc Hydro Geodatabase Visual Basic ArcGIS Relational Database (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

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

Lntegration of Hydrologic Data and Models Integration of data, data models, and analyses in a functional system GIS MIKE 21 HMS SWAT WRAP MIKE 11 RAS Other …

Integration Issues (direct interfacing) GIS MIKE 21HMS SWAT WRAP MIKE 11 RAS Other … N N * (N - 1) Bi-directional

Integration Issues (intermediary interfacing) GIS MIKE 21HMS SWAT WRAP MIKE 11 RAS Other … N 2 * N Bi-directional XML

GIS External Data Analysis Package Customizable Export XML Structure Customizable Import XML Structure Import Data as XML Document Export GIS Data as XML Document Import Engine Export Engine Import Export Central Exchange Mechanism XML Import and Export to Arc Hydro

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 Accomplishments A simple, extensible geodatabase design Scale-independent Strong water resources network model Features integrated through relationships Supported by customized Arc Hydro toolset Integrates geospatial and temporal water resources information Simplifies connection to water resources models

Consortium Phase 2: Goals for –Add groundwater to Arc Hydro –Define protocol for data exchange with Arc Hydro using XML –Take advantage of ArcGIS version 9 developments (Model builder, schematic network generation, detailed terrain mapping) –Integrated terrain database What do we want to have 3 years from now that we don’t have now?