Groundwater resource identification for horticultural development in the Gascoyne Murchison region of Western Australia

摘要

The Gascoyne-Murchison Region of Western Australia is sparsely populated and depends entirely on groundwater for water supply. Currently, the only horticultural development is at Carnarvon, and the Gascoyne Murchison Strategy wishes to support the development of new large scale horticultural precincts across the region. The aim of this study was to identify key sites with potential for irrigated horticulture. The preferred criteria stipulated by the Gascoyne Murchison Strategy, was for groundwater salinity of less than 1,500 milligrams per litre, with renewable resources of at least 2 Gigalitres per annum. The model used for target selection was to identify low salinity areas within potentially high yielding aquifers, utilising digital geological information, existing bore data and previous studies. Prospective aquifers identified in the area were calcrete, limestone, dolomite and sandstone. Areas of low salinity within these aquifers generally occur in, or in close proximity to recharge areas, particularly where a major river crosses outcrop or subcrop of the aquifer. Selection of key targets focused on these areas. A total of fifty-four prospective areas were identified throughout the study area. Five key sites were recommended for further investigation, based largely upon groundwater salinity; actual and/or potential bore yields; and the size of the groundwater resource.