Victorian Aquifer Framework - Water Table

## **Abstract** \n\nThis dataset and its metadata statement were supplied to the Bioregional Assessment Programme by a third party and are presented here as originally supplied.\n\n\n\nDEPI originally engaged GHD to develop seamless 3D aquifer surfaces for the Victorian Aquifer Framework (VAF). The seamless mapping of aquifers across the state provides the fundamental framework for groundwater resource management, underpins development of a revised management structure for Victoria (the Secure Allocation Future Entitlement project funded by the National Water Commission) and contributes to the data needs of the Bureau of Meteorology National Groundwater Information System (NGIS). \n\n\n\nThe original dataset was produced by GHD in 2012 using (in part) data provided by Southern Rural Water Corporation and Goulburn-Murray Water Corporation. It has been subsequently amended by Hocking et al and SKM in 2013.\n\n## **Dataset History** \n\nA number of key input datasets were sourced as part of the process to derive the 3D aquifer surfaces. These datasets included: The DEPI State-wide Stratigraphic Database (SSD); The National Groundwater Information System (NGIS) database containing groundwater borehole location information as well as lithological and stratigraphic information; Raster layers previously produced for Southern Rural Water (SRW) by SKM and GHD in 2009; The crystalline basement surface provided by the former Department of Primary Industries (DPI); Outcrop 1:250,000 scale geological mapping compiled by the former Geological Survey of Victoria, DPI; A state-wide 100m Digital Elevation Model (DEM) based on the DEPI 20m DEM. This was used to represent the natural surface; Data generated using DEPI's state-wide ecoMarkets groundwater modelling package to assist with the definition of key layers of the major Cainozoic aquifers; Latrobe Valley Coal Model which was used to provide a framework for the hydro-stratigraphy of the wet Gippsland Basin; Rasters of the top elevation of the major aquifer systems covering the Kiewa, Ovens, Goulburn-Broken and Loddon and Campaspe catchments; Data extracted from the Basin in a Box, the Murray Basin Hydrological Map Series and the Murray-Darling Basin Groundwater Status 1990-2000: Summary Report; Airborne magnetic data publicly available from raster data published by the former Geological Survey of Victoria, DPI. Once the input data had been compiled, the VAF 3D surfaces were developed by lfollowing a number of key steps, summarised below: (1) Contours as polylines and aquifer extents as polygons were extracted from previous mapping surfaces; (2) Outcrop points attributed with values from the DEM were created; (3) Based on the state-wide stratigraphic database, the contours and extents were refined or created; (4) A top elevation raster was interpolated using contours, outcrop points and bore data then replacing outcrop areas with the DEM; (5) The aquifer thickness was then checked in GIS by comparing layers against each other and assessing for cross-overs and negative thickness; (6) The input data was then revised and bore data, contours, and aquifer extents modified as required due to errors in the thickness; (7) If there were subsequent issues identified such as overlaps between aquifers, mismatches between bores and resulting layers, then the process was revised by returning to Step (3); (8) If the layers were matching well, then extent points were created to smooth layers at the edges; (9) A top elevation raster was generated again using contours, outcrop points, extent points and bore data; (10) The aquifer thickness was checked again, and if significant issues were identified, then the process returned back to Step (3) for further iteration; (11) Further modifications were applied to remove negative thicknesses and to provide minimum thickness of overburden; (12) Top and bottom elevation rasters were then generated at 100m pixel resolution to form the final dataset. In generating each of the layers, a number of Quality Assurance (QA) measures were implemented at various stages of the process. These included a topologic review, a hydrogeological review and an external reveiw by Spatial Vision. The original dataset was published in May 2012 and subsequent revisions have been conducted by Hocking et al and SKM in 2013.\n\n## **Dataset Citation** \n\nVictorian Department of Environment and Primary Industries (2014) Victorian Aquifer Framework - Water Table. Bioregional Assessment Source Dataset. Viewed 11 July 2016, http://data.bioregionalassessments.gov.au/dataset/663871a0-0444-4be4-bd2b-6741e114036e.

**摘要**
本数据集及其元数据声明由第三方提供给生物区域评估计划（Bioregional Assessment Programme），本文档按原始提交版本呈现。

维多利亚州环境与初级产业部（DEPI）最初委托GHD为维多利亚含水层框架（VAF）研发无缝三维含水层曲面。覆盖全州的含水层无缝制图为地下水资源管理提供了基础框架，为维多利亚州修订后的管理架构（由国家水资源委员会资助的“保障分配未来权益项目”）提供支撑，并满足了澳大利亚气象局国家地下水信息系统（NGIS）的数据需求。

原始数据集由GHD于2012年制作，部分数据由南部农村水务公司（Southern Rural Water Corporation）和古尔本-默里水务公司（Goulburn-Murray Water Corporation）提供。该数据集后于2013年由霍金等人与SKM进行修订。

**数据集历史**
为推导三维含水层曲面，本项目征集了若干关键输入数据集，具体包括：DEPI全州地层数据库（SSD）；包含地下水钻孔位置信息、岩性与地层信息的国家地下水信息系统（NGIS）数据库；SKM与GHD于2009年为南部农村水务（SRW）制作的栅格图层；前初级产业部（DPI）提供的结晶基底曲面；由前维多利亚州地质调查局（隶属于DPI）编制的1:25万比例尺露头地质图；基于DEPI 20m数字高程模型（DEM）制作的全州100m分辨率数字高程模型，用于表征自然地表；利用DEPI全州ecoMarkets地下水建模套件生成的、用于辅助界定主要新生代含水层关键地层的数据；拉特罗布谷煤炭模型，用于为湿润的吉普斯兰盆地水文地层学提供框架；覆盖基瓦、奥文斯、古尔本-布鲁肯、洛登与坎帕斯普流域的主要含水层系统顶部高程栅格；从“Basin in a Box”、默里盆地水文图系列以及《1990-2000年墨累-达令盆地地下水状况：总结报告》中提取的数据；由前维多利亚州地质调查局（隶属于DPI）发布的公开航磁栅格数据。

输入数据汇编完成后，VAF三维曲面通过以下关键步骤研发而成，概述如下：
(1) 从既往制图曲面中提取作为多段线的等高线与作为多边形的含水层范围；
(2) 生成带有DEM数值属性的露头点；
(3) 基于全州地层数据库，对等高线与含水层范围进行细化或新建；
(4) 利用等高线、露头点与钻孔数据插值生成顶部高程栅格，随后将露头区域替换为DEM数据；
(5) 在地理信息系统（GIS）中通过逐层比对、检查交叉与负厚度情况，核查含水层厚度；
(6) 因厚度存在误差，对输入数据进行修订，按需调整钻孔数据、等高线与含水层范围；
(7) 若后续识别出含水层重叠、钻孔与生成图层不匹配等问题，则返回步骤(3)重新开展流程；
(8) 若图层匹配效果良好，则生成范围点以平滑图层边缘；
(9) 再次利用等高线、露头点、范围点与钻孔数据生成顶部高程栅格；
(10) 再次核查含水层厚度，若发现显著问题，则返回步骤(3)进行迭代优化；
(11) 进行进一步修改以消除负厚度，并设置覆盖层最小厚度；
(12) 生成100m像素分辨率的顶部与底部高程栅格，形成最终数据集。

在各图层生成过程中，项目在多个阶段实施了质量保证（QA）措施，包括拓扑审查、水文地质审查，以及由Spatial Vision开展的外部审查。原始数据集于2012年5月发布，后于2013年由霍金等人与SKM完成修订。

**数据集引用**
维多利亚州环境与初级产业部（DEPI）(2014) 维多利亚含水层框架——地下水位。生物区域评估源数据集。查阅于2016年7月11日，http://data.bioregionalassessments.gov.au/dataset/663871a0-0444-4be4-bd2b-6741e114036e.