Current, Innovative, and Standardized Elevation Data for Flood Modeling in Australia: The Murray-Darling Basin Kea M. Beiningen, CFM, GISP Intermap Technologies May 19, 2010

© 2009 Intermap Technologies. All rights reserved. 2 Water Act 2007 The purpose of the Basin Plan is to provide for the integrated management of the Basin water resources in a way that promotes the objects of this Act, in particular by providing for: (a) giving effect to relevant international agreements (to the extent to which those agreements are relevant to the use and management of the Basin water resources); and (b) the establishment and enforcement of environmentally sustainable limits on the quantities of surface water and ground water that may be taken from the Basin water resources (including by interception activities); and (c) Basin-wide environmental objectives for water-dependent ecosystems of the Murray-Darling Basin and water quality and salinity objectives; and (d) the use and management of the Basin water resources in a way that optimizes economic, social and environmental outcomes; and (e) water to reach its most productive use through the development of an efficient water trading regime across the Murray-Darling Basin; and (f) requirements that a water resource plan for a water resource plan area must meet if it is to be accredited or adopted under Division 2; and (g) improved water security for all uses of Basin water resources.

© 2009 Intermap Technologies. All rights reserved. 3 NEXTMap® Data Interferometric Synthetic Aperture Radar (IFSAR) © 2010 Intermap Technologies. All rights reserved. 3

© 2009 Intermap Technologies. All rights reserved. 4 Intermap’s Core Products ORI Orthorectified Radar Image Image pixel size of 0.62 Meters DSM Digital Surface Model DTM Digital Terrain Model 4 © 2010 Intermap Technologies. All rights reserved. Pixel Size (m)RMSE (m)

© 2009 Intermap Technologies. All rights reserved. 5 Travellers Lake, Australia Google Earth, Spot ImageDSM on top of image

© 2009 Intermap Technologies. All rights reserved. 6 NEXTMap Specs Measures of Accuracy (Meters) Product TypeRMSE95%Mean and Standard Deviation I II DTM: Measures of Accuracy Product TypeRMSE95%MeanStandard Deviation I II III DSM:

© 2009 Intermap Technologies. All rights reserved. 7 Source Data Used Base data provided by MDBA 568 tiles of NEXTMap data from Intermap MGA Zone 54 projection (same as UTM 54 South) GDA 1994 datum Each tile 10 km by 10 km Array of 2000 x meter cells Vertical datum is AUSGeoid98 Vertical and horizontal units are meters Orthorectified radar images (ORI)

© 2009 Intermap Technologies. All rights reserved. 8 Overview Analyzed basin: ~46,000 sq km Hydrology: Regression equations function of drainage area in square kilometers Riverine-Like Hydraulics: 2-, 10-, 50-, 100-, and 500-year return intervals for riverine areas Non-Riverine Hydraulics: Pits and ponds Floodplain Mapping: Pits & Ponds + Riverine ArcHydro data model

© 2009 Intermap Technologies. All rights reserved. 9 Assumptions & Limitations Pilot-level study, test purposes only Highly automated, minimal human intervention Broad assumptions in certain input values Very short production time frame (December 2009) Used best available input data at time of work

© 2009 Intermap Technologies. All rights reserved. 10 Riverine-like Portions of Study Area Steady flow hydraulic models and mapping developed where: Drainage areas 20 sq km or more Contributing area completely contained by the supplied topography. Where the reaches somewhat riverine in nature PBS&J Rapid Floodplain Delineation (RFD) tool used Step-backwater computation Ability to write HEC-RAS files

© 2009 Intermap Technologies. All rights reserved. 11 Topography Used Common industry standard for hydrologic analysis is 30- meter cells used to develop basins and flowpaths for hydrology. For this project, topography resampled to 25-meters (slightly smaller than typical 30-meter cell size) Hydraulics Resampled to a 10-meter cell size for speed of analysis reasons Flowpaths were "splined" to smooth them out

© 2009 Intermap Technologies. All rights reserved. 12 Regression Equations for Flows Annual peak flow gage data available for portions of region Gage annual maximum peak flow series fitted to the Gumbel (Type 1) Extreme Value distribution. 2-, 10-, 50-, 100-, and 500-year Flow equation developed where drainage area was only variable

© 2009 Intermap Technologies. All rights reserved. 13 Cross Sections (XS) Cross Sections RFD has several parameters that impact XS placement For this pilot study, values set reach- by-reach in GIS Very minimal manual manipulation of XS for this study Standard Manning n value used

© 2009 Intermap Technologies. All rights reserved. 14 Dry Lakes and Pits / Ponds Only about 25% of the basin riverine-like Rest appears has few or no discernable channels—is not riverine flow. “Ponding" layer shows ponds & pits In excess of about 0.3 meters in depth And, approximately 1 hectare in surface area. Over 50,000 polygons in the study area Use pits-ponds layer from riverine models in conjunction with the ponding layer. Greater extent of two layers is estimated floodplain

© 2009 Intermap Technologies. All rights reserved. 15 Murray and Darling Rivers Majority of contributing basins outside the study area Effects of regulation Modeled using historic peak flows from early 1990s For Murray River Flows roughly equal to 1956 flooding extents also used ~2,265 cms U/S of the Darling ~2,549 cms D/S of the Darling

© 2009 Intermap Technologies. All rights reserved. 16 Murray and Darling Rivers

© 2009 Intermap Technologies. All rights reserved. 17 Floodplain Mapping Flow Contained

© 2009 Intermap Technologies. All rights reserved. 18 Floodplain Mapping Murray River + Pits and Ponds

© 2009 Intermap Technologies. All rights reserved. 19 Floodplain Mapping Overlaid With Basin Boundaries

© 2009 Intermap Technologies. All rights reserved. 20 ArcHydro Arc Hydro Tools version 1.3 used Created after H&H modeling complete Arc Hydro preprocessing workflow used In this case, workflow begins with the flow direction grid

© 2009 Intermap Technologies. All rights reserved. 21 ArcHydro Drainage, Hydrography, and Network feature datasets These are standard feature datasets in the Arc Hydro schema Drainage feature dataset watershed, catchment, and drainage line features Network dataset connectivity of the system Hydrography dataset Monitoring point features (gauges) Channel feature dataset Not included, no channel data available

© 2009 Intermap Technologies. All rights reserved. 22 What’s next??? Intermap continuing to collect IfSAR for the rest of Murray Darling Basin & now for the Eastern part of New South Wales.