Land Resources of the Lake Cootharaba Catchment
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Land Resource Assessment – Land Resources of the Lake Cootharaba Catchment South East Queensland August 2015 This publication has been compiled by DG Smith and MH Crawford of Technical Support, Resource Assessment and Information, Department of Natural Resources and Mines. © State of Queensland, 2015 The Queensland Government supports and encourages the dissemination and exchange of its information. The copyright in this publication is licensed under a Creative Commons Attribution 3.0 Australia (CC BY) licence. Under this licence you are free, without having to seek our permission, to use this publication in accordance with the licence terms. You must keep intact the copyright notice and attribute the State of Queensland as the source of the publication. Note: Some content in this publication may have different licence terms as indicated. For more information on this licence, visit http://creativecommons.org/licenses/by/3.0/au/deed.en The information contained herein is subject to change without notice. The Queensland Government shall not be liable for technical or other errors or omissions contained herein. The reader/user accepts all risks and responsibility for losses, damages, costs and other consequences resulting directly or indirectly from using this information. Summary The land resource assessment of the Lake Cootharaba catchment was produced to inform and support strategic planning decisions. It presents soil physical and chemical attributes and land resource limitations to assist planning for competing land uses, specifically involving land suited to agricultural production. Soil and landscape attributes were assigned to unique mapping areas based on information sourced from a total of 311 sites. The 266 project sites were supplemented with information from an additional 45 sites described in previous studies which overlapped the current study area, including sites from South East Queensland acid sulfate soils projects and South East Queensland pasture trial projects. Conceptual soil descriptions known as soil profile classes were then used to describe the associations between soils and the landforms on which they occur. The complex of 24 soil profile classes and 574 unique mapping areas identified within the survey area reflects the diverse range of geologies and landforms found in the catchment. Soil and landscape attributes were used to assess the limitations of each unique mapping area and therefore their suitability for a wide range of agricultural and horticultural uses. Using the process herein, it was determined that 19% (4 855 ha) of the catchment is class A1 cropping land, 36% (9 445 ha) is class A2 horticultural land, 2% (546 ha) is class B limited crop land while the remainder is grazing land or non-agricultural land (class C or D). Therefore, a total of 57% (14 846 ha) of the catchment is considered potential cropping land, much of which exists along Kin Kin Creek, its tributaries and on surrounding gentle slopes. This land resource assessment identified soil types in the Lake Cootharaba catchment and the location and quality of land suited to agricultural and horticultural production. This information will inform future local and regional planning decisions made by land holders, industry groups, community groups, state and local government departments and other land managers. Land Resources of the Lake Cootharaba Catchment – South East Queensland i Contents Acknowledgements ............................................................................................................................... 1 Introduction ............................................................................................................................................ 2 Study area ............................................................................................................................................... 4 Climate .................................................................................................................................................... 5 Geology ................................................................................................................................................... 7 Land use ................................................................................................................................................. 9 Methodology ......................................................................................................................................... 10 Formation of soil-landscape associations ............................................................................................ 10 Determination of land suitability attributes ........................................................................................... 11 Calculation of plant available water capacity ....................................................................................... 11 Attribute modelling ............................................................................................................................... 12 Verification of results ............................................................................................................................ 20 Soils and soil-landscape units ........................................................................................................... 22 Coastal dunes and associated swales (Qhd, Qpb-SEQ, Qpd) ............................................................ 23 Beach ridges (Qhd, Qpb-SEQ, Qpd) ................................................................................................... 24 Quaternary alluvium – stream alluvia (Qa) .......................................................................................... 25 Quaternary alluvium – active and extra-tidal lake alluvia (Qc, Qhl/c, Qa, Qlc, Ql/s, Qcw) .................. 28 Myrtle Creek Sandstones (RJdm) ........................................................................................................ 29 Northern and eastern facing slopes ................................................................................................... 29 Southern and western facing slopes .................................................................................................. 31 Myrtle Creek Sandstones on low rises .............................................................................................. 32 Tiaro Coal Measures (Jdt) ................................................................................................................... 34 Soils on deeply weathered mudstone/siltstone.................................................................................. 34 Soils derived from fine sandstones .................................................................................................... 34 Uniform sandy soils forming on Tiaro Coal Measures or colluvium derived from Myrtle Creek Sandstone .......................................................................................................................................... 35 Deeply weathered Myrtle Creek Sandstones and deeply weathered Tiaro Coal Measures (RJdm(w), Jdt(w), Qr-SEQ>Jdt) ............................................................................................................................ 36 Phyllites (Rk) ........................................................................................................................................ 37 Granites (Rgw/g) .................................................................................................................................. 38 Rhyolitic tuff (Rv) .................................................................................................................................. 39 Rhyolites (Ti) ........................................................................................................................................ 40 Neogene basalts (Tb-SEQ) .................................................................................................................. 40 Land evaluation .................................................................................................................................... 43 Land suitability ..................................................................................................................................... 43 Agricultural land classification .............................................................................................................. 45 Land Resources of the Lake Cootharaba Catchment – South East Queensland ii References ............................................................................................................................................ 48 Appendices ........................................................................................................................................... 50 Appendix 1 – Land suitability classes ............................................................................................... 51 Appendix 2 – Agricultural land classifications ................................................................................. 53 Appendix 3 – Land suitability classification scheme ....................................................................... 54 Frost (Cf) ............................................................................................................................................. 58 Cf – Climate – frost .........................................................................................................................