This dataset was compiled for the purposes of the Secure Allocations Future Entitlements (SAFE) project. The SAFE project was funded by the Commonwealth Government under the Nartional Groundwater Action Plan to progress the managment of groundwater in Victoria.
A number of datasets were used to produce the Watertable Elevation Surface included bore readings of watertable depth and a digital terrain model for the state. Existing models of watertable geometry from a number of projects were also incoroporated into the mapping process.
At the conclusion of the project, a model based on watertable elevation in mAHD was produced at a 100m resolution.
Search Words:
Inland waters
,
Geoscientific information
Publication Date:
Dataset Status:
Victoria
Progress:
Completed
Access Constraint:
Creative Commons Attribution 4.0 (CC-BY)
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License Text
)
General
Data Existence:
Metadata Name
Descriptions
Resource Name:
WATERTABLE_ELEVATION_SURFACE
Title:
Watertable Elevation Surface
Anzlic ID:
ANZVI0803004971
Custodian:
Owner:
Jurisdiction:
Victoria
Abstract:
This dataset was compiled for the purposes of the Secure Allocations Future Entitlements (SAFE) project. The SAFE project was funded by the Commonwealth Government under the Nartional Groundwater Action Plan to progress the managment of groundwater in Victoria.
A number of datasets were used to produce the Watertable Elevation Surface included bore readings of watertable depth and a digital terrain model for the state. Existing models of watertable geometry from a number of projects were also incoroporated into the mapping process.
At the conclusion of the project, a model based on watertable elevation in mAHD was produced at a 100m resolution.
Search Words:
Inland waters
,
Geoscientific information
Purpose:
Geographic Extent Polygon:
Geographic Bounding Box:
-34
141
150
-39
Beginning to Ending Date:
2011-06-30 - 2012-02-29
Maintainence and Update Frequency:
As needed
Stored Data Format:
DIGITAL: ESRI ASCII GRID, ESRI GRID, JEPG2000 2
Available Format(s) Types:
DIGITAL
Positional Accuracy:
This dataset has been derived from datasets of varying and not always known accuracy.
Attribute Accuracy:
Not known and has not been assessed.
Logical Consistency:
Not known.
Data Source:
Dataset Source: A review was undertaken of such issues as the distribution of available data and existing watertable models, the broad hydrogeological systems and existing hydrological divisions of the state. Subsequently, it was decided that the watertable model would be compiled as a series of sub areas approximately reflecting the geometry of the Catchment Management Authority Areas (CMA).
Compilation of the watertable geometry utilised three main methodologies.
The first method involved those CMAs south of the divide in the Southern Rural Water (SRW) area. The watertable geometry from a previous SRW project was adopted. This was modified in some areas as explained later for each CMA.
The second involved a terrain analysis technique based on the premise that the watertable is a smoothed and subdued reflection of topography. This technique is best used in regions of sparse bore data and complex topography/watertable. It is less suitable for plains regions with little topographic relief and where there tends to be the highest concentration of bore data. Within the basement areas of the watertable aquifer the result of this analysis was adopted as the watertable model.
The third method involved using the available bore data and the output from the second method as input to the surface modelling utility ANUDEM. ANUDEM is a program that calculates regular grid digital elevation models with sensible shape and drainage structure from arbitrarily large data sets. While traditionally used to create terrain models, ANUDEM is ideally suited for compiling any surface that has significant direction or flow control such as groundwater geometry. ANUDEM was used to compile the watertable geometry over the plains and other non basement areas.
For those CMA areas north of the divide a combination of methods two and three were adopted.
The resultant watertable surface for each CMA was then validated against the bore data. Differences between the surface and the bore data have three main causes.
(1) The surface compiled from the bore data (as per the southern CMA and basement areas);
(2) The 27 year temporal range of the data resulting in an average surface being created;
(3) The positional accuracy of the bore location making a comparison not valid.
Dataset Originality: Derived
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