A Review of Salinity Occurrences in the Queensland Murray-Darling Basin, 2002
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276 A review of salinity occurrences in the Queensland Murray-Darling Basin, 2002 A.J.W. Biggs, R.E. Power Department of Natural Resources and Mines Toowoomba, 2003 QNRM03018 ISBN 0 7345 2441 2 This project was supported by funding from the Natural Heritage Trust. Project partners were the Queensland Murray-Darling Committee Inc. and Conservation Farmers Inc. This publication was prepared by Department of Natural Resources and Mines officers. It may be distributed to other interested individuals and organisations. This report is intended to provide information only on the subject under review. Before acting on the information conveyed in this report, readers should ensure that they have received adequate professional information and advice specific to their enquiry. While all care has been taken in the preparation of this report, neither the Department of Natural Resources and Mines nor its officers or staff accepts any responsibility for any loss or damage that may result from any inaccuracy or omission in the information contained herein. Other reports in this series include: Biggs, A.J.W. and Power, R.E. (2003). Review of, and recommendations for, salinity monitoring in the Queensland Murray-Darling Basin. Department of Natural Resources and Mines, Brisbane, Queensland, QNRM03022. Biggs, A.J. W., Power, R.E. and Brough, D.M. (2003). A preliminary assessment of salinity risk modelling in the Queensland Murray-Darling Basin. Department of Natural Resources and Mines, Queensland. QNRM03155. Mahawattege, J., Harth, G., Biggs, A.J.W. and Power R.E. (2003). Shallow groundwater investigations in the Queensland Murray-Darling Basin. Department of Natural Resources and Mines, Queensland. QNRM03019. Tolmie, P.E., Silburn, D.M. and Biggs, A.J.W. (2003). Estimating deep drainage in the Queensland Murray-Darling Basin using soil chloride. Department of Natural Resources and Mines, Queensland. QNRM03020. Yee Yet, J., Silburn, D.M. (2003). Deep drainage estimates under a range of land uses in the Queensland Murray-Darling Basin using water balance modelling. Department of Natural Resources and Mines, Queensland. QNRM03021. © State of Queensland, Department of Natural Resources and Mines, 2003 Department of Natural Resources and Mines Locked Bag 40 Coorparoo DC Qld 4151 QMDB salt site review, 2002 iii Contents Scope of this report ..................................................................................................v Summary...................................................................................................................vi Recommendations ..................................................................................................vii 1. Introduction ..........................................................................................................1 1.1 Attributes of the QMDB ...............................................................................................1 1.2 General concepts of salinity ........................................................................................7 1.2 Historic extent ...........................................................................................................10 2. Current review ....................................................................................................13 2.1 Methodology..............................................................................................................13 2.2 Extent of secondary salinity ......................................................................................13 2.3 Discussion.................................................................................................................17 2.4 Uncertainty ................................................................................................................32 3. References ..........................................................................................................37 Glossary...................................................................................................................43 Appendix 1 Common salinity models in Queensland .........................................45 Appendix 2 Salinity site description checklist.....................................................47 Tables Table 1 Remnant vegetation statistics by catchment, QMDB........................................................... 7 Table 2 Saline sites by QMDB catchment ...................................................................................... 14 Table 3 Area of salinity by sub-catchment......................................................................................14 iv Figures Figure 1 Typical salt profile of a Grey Vertosol (Kupunn) in the eastern QMDB............................ 6 Figure 2 EC in Red Kandosol catena, St George .............................................................................. 9 Figure 3 Red material/Marburg sandstone interface near Haden .................................................... 18 Figure 4 Size and percentage distribution of salt outbreaks, Oakey district ................................... 18 Figure 5 Salt affected lucerne, Umbiram ........................................................................................19 Figure 6 Seepage salting on a basalt sandstone interface................................................................ 19 Figure 7 Water levels vs rainfall for a basaltic uplands bore (RN42231363) ................................. 20 Figure 8 Water levels in some eastern Darling Downs piezometers............................................... 20 Figure 9 Episodic seep at basalt-Marburg interface near Haden..................................................... 21 Figure 10 Seepage salting on Marburg sandstones, Warwick......................................................... 22 Figure 11 Episodic saline seeps in footslopes of fine grained sediments........................................ 23 Figure 12 Salinity in Griman Creek Formation, Weengallon ......................................................... 23 Figure 13 Saline expression at contact of hillslope and alluvia on Glen Creek .............................. 25 Figure 14 Scalding adjacent to a leaking dam in the Granite Belt .................................................. 25 Figure 15 Ternary plot, Leslie dam catchment................................................................................ 26 Figure 16 Salinity related to excessive leakage from irrigated lands in the Granite Belt ............... 27 Figure 17 Schematic cross-section of lateral flow in the granite belt ............................................. 27 Figure 18 Salinity from shallow groundwater adjacent to Coolmunda Dam .................................. 29 Figure 19 Broad valley in Permian sediments at Pikedale .............................................................. 29 Figure 20 Salt crust on Permian sediment outcrop, “Terrica”......................................................... 30 Figure 21 Yelarbon Desert .............................................................................................................. 31 Figure 22 Five year moving average rainfall, Pittsworth ................................................................ 33 Maps Map 1 Queensland Murray-Darling Basin ........................................................................................ 3 Map 2 Generalised geology of the QMDB........................................................................................ 4 Map 3 GFS of the QMDB ................................................................................................................. 5 Map 4 Location of salinity expressions in the QMDB.................................................................... 15 Map 5 Distribution of some key landscapes in the QMDB............................................................. 16 Acknowledgements The authors wish to acknowledge the contributions and assistance of Ian Gordon, Clive Knowles- Jackson, Paul Webb, Michael Jamieson, Denise Parkinson, Sandra Vonhoff, David Burton and Diane Bray. QMDB salt site review, 2002 v Scope of this report This report has been prepared to meet in part the objectives of the MD2001 funded project “Managing dryland salinity in the Queensland Murray-Darling Basin”. As with previous surveys, this review was targeted at documenting induced (secondary) salinity rather than “natural” (primary) salinity expressions, and did not include non-saline scalded lands. vi Summary A review of the nature and extent of dryland salinity expressions was undertaken for the Queensland Murray-Darling Basin, concentrating primarily on the eastern half of the Basin. The review builds upon the state-wide survey of salt expressions compiled in 1991, and other historical works for the Basin. One hundred and ninety-four salt expressions were identified, affecting a known area of approximately 9428 ha and an estimated total area of 10 198 ha. The currently mapped extent is suggested to be a significant under-estimate, with a revised estimate suggested to be approximately 14 600 ha. This is less than recent Australian Bureau of Statistics estimates of approximately 29 000 ha. The majority of salt expressions occur on the western fringes of the basaltic uplands in the Condamine catchment. The next most affected areas are the Marburg sandstones and Granite Belt landscapes of the upper Condamine and Border Rivers catchments. The causal factors and processes vary within landscapes, but basalt form and catena form are the two