River Murray Flood Mapping

Dataset description contents:

Note: this dataset description is metadata (data about data) which describes the actual dataset in accordance with the ANZLIC (Australia New Zealand Land Information Council) Core Metadata Guidelines Version 2 (February 2001)

Citation

ANZLIC unique identifier: ANZCW1201000210

Title: River Murray Flood Mapping

Custodian: Planning SA (South Australian data) and Murray-Darling Basin Authority (SA border to Lake Hume)

Jurisdiction: Australia


Description

Abstract:

River Murray Flood Mapping represents the extent of flooding based on historical records and some associated information (eg. flood depth contours and levels) captured by two different projects for (1) the River Murray from the mouth to the South Australian border, and (2) the River Murray from the South Australian border to Lake Hume. The flood information for the South Australian section of the River Murray was obtained from the South Australian Government by the Murray-Darling Basin Authority (MDBA), and represents the extent of the 1956 flood. The information for the River Murray upstream of the South Australian border was produced for the MDBA to support environmental planning along the River Murray, such as NSW Murray Regional Environmental Plan No 2 (note that the flood information was collected in a uniform and consistent fashion for both the NSW and Victorian sides of the floodplain). Accuracy and reliability of mapping was subject to the quality of data available at the time the mapping was undertaken. The Victorian Department of Natural Resources and Environment (DNRE), who undertook the flood information mapping upstream of South Australia on behalf of MDBA as part of a Natural Resource Management Strategy (NRMS) project, is currently producing detailed metadata to support the mapping, for example specifying the sources of data for each flood information segment. Please note that the flood mapping data is preliminary until complete metadata has been constructed.

ANZLIC search words:

Spatial domain:

Geographic bounding box:

The bounding box encloses the maximum extents of the dataset. There may be voids or gaps within the bounding box, depending on the defined coverage of the dataset. Outer bounding rectangle as Latitude/Longitude coordinates based on the WGS84 datum (expressed as both Degrees Minutes Seconds and as decimal Degrees):

  • North bounding latitude: -33.94

  • South bounding latitude: -36.19

  • East bounding latitude: 147.2

  • West bounding latitude: 139.56

    • locality map

    Data Currency

    Beginning date: 01 January 1998 (01-1-1998)
    Ending date: 31 December 1999 (31-12-1999)

    Data Status

    Progress: Complete
    Maintenance and update frequency: Not Planned

    Access

    Stored Data Format:
    Digital:
    ArcInfo

    Available Data Format:
    Digital:
    ArcInfo

    Access Restrictions:

    MDBA Copyright conditions and SA Government licence constraints

    Data quality

    Lineage:

    (1) River Murray mouth to South Australian border: The data for this part of the River Murray represents the extent of land flooded during the 1956 flood event. The coverage was captured from 1:10,000 mylars as a dataset by the Geographic Analysis and Research Unit (part of SA Dept of Transport, Urban Planning and the Arts - Planning SA) and the Resources Information Group (part of SA Dept of Environment, Heritage and Aboriginal Affairs). (2) River Murray from the South Australian border to Lake Hume: Available Aerial Photography This is a major source of information in establishing the extent of flooding for particular events. Landsat & Spot Imagery This information is used where aerial photography is not available. These images were used in conjunction with the theoretical analytical programs HEC 2 and MIKE 11, and any other information available. The Victorian Department of Natural Resources and Environment (DNRE) has many gauging sites along the river and flow data for various historical flood events. Statistical analysis of this data enables the determination of different return period flows. The theoretical 1% flow is then used with the analytical models HEC 2 and MIKE 11 to establish a difference in flow level between the known events and the theoretical 1% level. Differentials between known flood events and theoretical one percent flow, established at existing gauging stations, can be used to create 1% longitudinal profiles. In the absence of the above information, geomorphological, soil and vegetation maps are used to define flood extents. These sources are respectively less reliable than any of the above methods. Criteria for Mapping 1. Levee Banks a) Private Ownership Licensed (NSW) and unlicensed levees (Vic and NSW) that have been constructed by individuals are deemed not to exist for the purposes of flood mapping. The reasons these banks are ignored are that they have been constructed to various standards of height, construction quality and different protection levels, and maintenance is almost nonexistent. Even if some banks have been constructed to a reliable standard, the fact that many others in the area are not could result in failures and subsequent flooding, ie. the unreliability of most banks condemns the better banks to the same lower classification.. b) Public Ownership Main public levees, ie. levees managed by Shires, Government Departments or Water Management Authorities, are deemed to have interaction with floods because these authorities are responsible for these levees and the consequences of any failure. Also public authorities nearly always adhere to strict design, construction and maintenance standards. 2. Roads and Railways These are considered to be barriers, because they are generally built to appropriate engineering standards and have generally stood the test of time in retaining floodwaters. 3. Channels a) Main trunk channels that are maintained by a Public Authority are considered to be barriers depending on their height. This is because they have been constructed to an appropriate standard. b) Private channels are not considered to be barriers because of their often irregular height. They are usually smaller than channels controlled by public authorities, their banks are not as high and they would normally be expected to be overtopped by a major flood event. Their standard of construction is not known and maintenance standard varies significantly with the different owners. 4. Private Farm Drains & Authority Farm Drains. These drains are constructed at low points and with gaps in spoil banks. Generally, the spoil banks are well below the major flood event`s extent of flooding. 5. Flood Protected Areas - Special Notes Notwithstanding any of the above considerations, special notations are used to indicate areas that are protected from flooding by artificial means. For example, "This area is protected from flooding but may flood in the event of the Channel/Main Road/Levee is overtopped or breached." The flood mapping used the First Edition River Murray Mapping orthophotos for base mapping. The data was reprojected from UTM AGD66 datum and Australian National spheroid to UTM WGS84 datum and spheroid.

    Positional Accuracy:

    (1) For the mapping from the River Murray mouth to the South Australian border: As far as can be ascertained, the information is correct to the scale of capture (1:10,000 scale). (2) For the mapping from the South Australian border to Lake Hume: The base mapping used (First Edition River Murray Mapping orthophotos) has been designed to comply with standard accuracy associated with 1:25,000 topographic mapping, ie. 90% of features identifiable on the orthophoto located within 12.5 metres (ie. 0.5 mm at 1:25,000 scale) of true ground position. However, the flood mapping, being a derived information product, is likely to be somewhat less accurate than this.

    Attribute Accuracy:

    (1) For the mapping from the River Murray mouth to the South Australian border, the attribute accuracy is to within design standards. (2) For the mapping from the South Australian border to Lake Hume: Historical floods, for example in 1917, 1974 and 1956 were mapped based on the best available information, for the purposes of environmental planning. Please note the data and mapping may not prove ideal for purposes other than for which they were designed.

    Logical Consistency:

    The major flood event coverages have full polygon topology and no label or node errors, with the other coverages having line and annotation attributes.

    Completeness:

    For each of the two regions, the flood information is seamless and is complete for the River Murray from the mouth to Lake Hume.

    Contact Information

    Contact organisation:Murray-Darling Basin Authority (Australia)
    Contact position: Natural Resource Information Coordinator
    Postal address:
    GPO Box 1801

    Canberra

    ACT, 2601

    Australia

    Telephone: 02 6279 0100
    Facsimile: 02 6230 7579
    Electronic mail address: gis@mdba.gov.au

    Metadata information


    Metadata date: 08 April 1998 (08-4-1998)

    This dataset description complies with ANZLIC Core Metadata Guidelines Version 2 (February 2001) and XML DTD ANZMETA 1.3

    Additional metadata

    Metadata format updated on 02/11/2005. GEOGRAPHIC EXTENT NAME:The Flood Mapping covers the entire River Murray floodplain from the mouth to below Hume Dam. This area currently excludes the Edward-Wakool river system (due to be completed late in 1999 by a separate study). Projection: Projection name: Universal Transverse Mercator (scale factor 0.9996); Units: metres; Datum: WGS84; Spheroid: WGS84; Zones: 54 or 55 (see below) Notes: The ARC/INFO data has been reprojected from its original AMG coordinate system to the WGS84 datum and spheroid that closely match (within 1 metre) the coordinate system used for the Second Edition River Murray Mapping orthophotos (GDA94). Data Dictionary: The flood information for upstream of South Australia has been converted from DGN format to ARC/INFO and was then separated into two layers. The first (EXT) describes the major flood event (a compilation of historical flood information from 1917 and other flood events). This layer has full polygon topology that allows the event to be shaded for `flooded` and `not flooded`. The second (ALL) describes flood mapping information for all years covered by the study and has line and annotation attributes. This layer does not have polygon topology. The South Australian data exists as a flood extent (EXT) layer only and does not contain the more comprehensive information of the ALL layer.PLEASE SEE "FLOOD.DOC" FOR ATTRIBUTE INFORMATION. Terms and Conditions for the Use of River Murray Mapping: Definition: River Murray Mapping includes all Murray-Darling Basin Authority (MDBA) copyrighted mapping and survey information, in both digital and hardcopy formats, of the River Murray and its associated riverine regions (eg. the floodplains of the Darling River, Mitta Mitta River and Murray anabranches). Specifically, River Murray Mapping includes: (1) aerial photography; (2) orthophotography; (3) ground control information; (4) wetlands, flood boundaries, levees; (5) riparian vegetation and habitats; (6) terrain (contours, point heights, DTM`s), and; (7) geomorphology. This information is copyright to the MDBA. Terms and Conditions The MDBA provides access to this data to cooperating users for non-commercial purposes providing they meet any formatting and transfer costs associated with the data. The terms of the copyright are: (1) The sale, transfer or reproduction of River Murray Mapping or derived products, in non-approved formats or for commercial purposes, whether by map or digital data, is prohibited without a licence in writing from the MDBA. Aerial photography, including photocopies, shall not be scanned or otherwise converted into digital format without prior written approval from MDBA. (2) All River Murray Mapping digital files and derived products will be deleted from computing and data storage systems upon completion of the approved use, unless written agreement is reached on royalties payable for retaining this data. (3) All mapping and publications using River Murray Mapping will acknowledge MDBA copyright. (4) The user accepts that Murray-Darling Basin Authority or Georeality Pty Ltd are not liable for any loss or damage incurred through the use of River Murray Mapping products. Failure to comply with the above terms and conditions is a breach of copyright.

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