Climate in the Pilbara

The Pilbara is characterised by very hot summers, mild winters and low and variable rainfall. It is classified as hot desert in northern and inland areas and hot grasslands in the north-west. The Pilbara claims a number of climate records: seven of Western Australia’s top 10 hottest days, with Mardie recording the hottest day on record — 50.5 degrees Celsius (°C) most sunshine hours a day in Australia (more than 10 hours a day) second highest inter-annual variability in rainfall (second only to central Australia) the most cyclone-prone area along the Australian coastline. During summer and early autumn (December to March), average daily temperatures exceed 30°C across the region, with average daily maxima exceeding 35°C from October to March. In northern inland areas, such as Marble Bar, average maxima exceed 40°C during summer and temperatures exceeding 45°C are common. During the winter months (June to August), average temperatures are around 20°C across the region. Coastal areas have a smaller annual temperature range compared to inland areas and winter temperatures rarely drop below 10°C. Except for the upland areas of the Hamersley Ranges and south-eastern inland areas, there is minimal risk of frost. Rainfall is spatially and temporally variable. There is a general trend for annual rainfall to decline from 300–350 millimetres (mm) in the north-east to less than 250 mm in the south and west. However, elevated areas in the Hamersley Ranges average more than 500mm. Rainfall is greatest during summer and autumn and least during winter and spring. Rainfall in the eastern Pilbara is most influenced by tropical and monsoonal drivers, which are predominantly active in summer and autumn, while rainfall in the western Pilbara is also influenced by southern mid-latitude drivers, such as frontal systems, during autumn and winter. Tropical cyclones (TCs) cause the most extreme rainfall events and generate 25–34% of the total annual rainfall near the Pilbara coast and as much as 21% up to 450km inland. While TCs make a critical contribution to rainfall in the north-west, their inter-annual contribution to summer rainfall ranges from 0 to 86%. Historically, TCs have caused considerable damage and loss of life in the Pilbara, but modern design regulations ensure that buildings and other infrastructure are now far less susceptible to damaging winds. However, even the threat of a TC can cause substantial economic losses to the mining and offshore oil and gas industries through lost production or disruptions to shipping activities. Hot, dry and sunny conditions mean the Pilbara is subject to very high evaporative demand. Point potential evaporation represents the evapotranspiration that would occur from small, well-irrigated fields surrounded by non-irrigated land and exceeds 3000 millimetres per year (mm/y) over much of the Pilbara. The higher areas of the Hamersley Ranges are cooler and subject to greater summer cloud cover and so have the lowest evaporative demand. Potential evaporation is greatest during the summer months — averaging 10–14 millimetres per day (mm/d) — and least during winter, averaging 4–7mm/d. Over the last 40–60 years, average annual temperatures have increased across most of Western Australia (WA). In the Pilbara, temperatures increased most during winter and spring and cooled during autumn and summer. Warming during the largely cloudless winter and spring is in line with global trends, and summer cooling is likely caused by increasing summer rainfall and associated cloud cover over north-western Australia. Annual rainfall increased over most of the Pilbara, except in the west where it decreased. Rainfall intensity and number of rain days have also increased in the central and eastern parts and decreased in the west. A decline in autumn and winter rainfall over the western Pilbara has coincided with major shifts in the large-scale atmospheric circulation of the southern hemisphere. These changes include a southward shift in the subtropical ridge and the southern hemisphere westerly jet stream. Future climate Climate projections show very high confidence (see Appendix D) for substantial temperature increases to continue in the Pilbara, with the north-west of WA warming more than elsewhere in Australia. Annual average temperature is projected to increase by 0.6–1.5°C by 2030 for all emission scenarios and by 1.5–3.1°C and 3.1–5.6°C by 2090 for medium (RCP4.5) and high (RCP8.5) emission trajectories, respectively (Appendix C explains the emission trajectories). Annual rainfall is projected to remain largely unchanged to 2090 and there is high confidence that natural rainfall variability will remain the primary driver of rainfall changes to 2030. There is medium confidence that TCs will become less frequent in future but will increase in intensity. There is high confidence that potential evaporation will increase but only medium confidence in the magnitude of the change.https://researchlibrary.agric.wa.gov.au/bulletins/1224/thumbnail.jp

The Physical and hydrological characteristics of a south coast sandplain site : east Howick site survey

This Technical Report documents the physical and hydrological characteristics of a farmland site on the Esperance Sandplain. The site was located on \u27Belalie Farm East\u27 110 km east of the town of Esperance in the locality of Howick (AMG 488900, 6277500) The site was typical of the sandplain landsystem which covers 35% (0.72 million ha) of the Esperance Agricultural Region. The farm was cleared over a number of years beginning in the 1970\u27s and an extensive network of windbreaks established

Tree windbreaks in the wheatbelt

Windbreaks comprising trees, or tree and shrub combinations, can offer many benefits on wheatbelt farms, particularly for protection of soil, stock, crops and pastures from damaging winds and erosion. Additional benefits include reduced evaporation from farm dams, reduced groundwater recharge, their use as nature conservation corridors and habitats, increased biodiversity including predators of crop and pasture pests, fire control, tree products and improved lifestyle and aesthetics. In other areas and farming systems such as intensive horticulture, man-made windbreaks may be used, but their higher cost makes them unsuited for broadscale agriculture. Man-made windbreaks can be effective in reducing evaporative losses from farm dams in the short to medium-term but become costly if they are engineered to withstand strong winds or last a long time.https://researchlibrary.agric.wa.gov.au/bulletins/1196/thumbnail.jp

Bioenergy and carbon farming opportunities in the Pilbara

The Pilbara region covers 270 000 square kilometres of north-west Western Australia. Its main agricultural land use is pastoralism, with beef cattle grazing native pastures. Currently, only 24km2 is under irrigation, with irrigated fodder the principal crop, but this could expand to 100km2. This expansion has the potential to significantly broaden the economic base of the Pilbara. Irrigation and the opportunities for changing land use and management may facilitate greater participation in the carbon economy by Pilbara land managers. Bioenergy feedstocks could be sourced from purpose-grown crops or agricultural wastes. Carbon farming activities may be facilitated by the land use and management changes that are possible with the introduction of irrigated agriculture into existing pastoral systems. This report investigates the potential for land managers in the Pilbara to produce bioenergy from feedstocks sourced from irrigated agriculture, and to undertake carbon farming activities that are facilitated by introducing irrigated agriculture.https://researchlibrary.agric.wa.gov.au/bulletins/1214/thumbnail.jp

Climate-ready agriculture: a situation statement for Western Australia

Projected future changes in the state’s climate will present new challenges for our producers. The Department of Agriculture and Food, Western Australia (DAFWA) continues to work with agricultural industries to lay solid foundations for an agricultural sector that has a range of response options. This situation statement provides an assessment of how climate-ready the state’s agricultural sectors are and provides guidance for investment priorities for DAFWA for the period 2015–2020.https://researchlibrary.agric.wa.gov.au/bulletins/1050/thumbnail.jp

Carbon farming in relation to Western Australian agriculture

Carbon farming activities need to return multiple economic and environmental co-benefits to be attractive to land managers. This bulletin summarises concepts underlying carbon farming, how Australia accounts for greenhouse gas emissions and the potential for Western Australian land managers to participate in, and benefit from, carbon farming.https://researchlibrary.agric.wa.gov.au/bulletins/1269/thumbnail.jp

Climate change: impacts and adaptation for agriculture in Western Australia

This bulletin reviews the latest scientific information relating to climate change and agriculture (broadacre, livestock, horticulture, pastoral industries) in Western Australia.https://researchlibrary.agric.wa.gov.au/bulletins/1043/thumbnail.jp

Crop Updates 2000 Cereals - part 4

This session covers twelve papers from different authors: BREEDING 1.Response to subsoil acidity of wheat genotypes differing in Al-tolerance, C. Tang, Z. Rengel, E. Diatloff and B. McGann, Soil Science and Plant Nutrition/CLIMA, University of Western Australia 2. Application of molecular markers in Barley Improvement, Mehmet Cakir1, Nick Galwey1 and David Poulsen2, 1Plant Sciences, Faculty of Agriculture, University of Western Australia, 2Queensland Department of Primary Industries, Hermitage Research Station, Queensland 3. Implementation of molecular markers for wheat improvement in the Western Region, M. Carter1, A. Briney1, R. Wilson2, R.H. Potter1 and M.G.K. Jones1, 1Western Australian State Agricultural Biotechnology Centre, Murdoch University, 2Crop Industries, Agriculture Western Australia 4. Performance in 1999 of recently released wheat varieties in Western Australia, Robin Wilson, Iain Barclay, Robyn McLean, Dean Diepeveen and Robert Loughman, Agriculture Western Australia ECONOMICS 5. Outlook for prices and implications for rotations, Ross Kingwell1 2, Michael O’Connell1, Simone Blennerhasset1 1Agriculture Western Australia, 2University of Western Australia 6. Price Risk Management and the Western Australian Grain Producer, Benjamin Michael Tiller, Muresk Institute of Agriculture FORECASTING 7. Can we forecast wheat yields in Western Australia, Senthold Asseng1, Holger Meinke2, and Bill Bowden3, 1CSIRO Plant Industry, 2 APSRU/DPI, 3Agriculture Western Australia ON FARM TESTING 8. On-farm testing, the quiet revolution continues, Jeff Russell1, Ivan Lee2 1Agriculture Western Australia, 2 Farmer Kunjin TopCrop group, Corrigin GRAIN STORAGE 9. CD-ROM tool for growers and advisers: Managing on-farm grain storage – effective practices for the delivery of quality assured products, Clare Johnson1, Chris Newman2 1Quality Wheat CRC Ltd, 2Production Resource Protection Services, Agriculture Western Australia 10. The Internet as a tool for managing grain insects, Robert Emery, Romolo Tassone and Ernestos Kostas, Agriculture Western Australia SUMMER CROPS AND WINDBREAK EFFECT ON YIELD 11. Summer crop Update and agronomic considerations, Graeme Ralph, Pioneer Hi-Bred Australia Pty Ltd 12. The effect of tree windbreaks on grain yield in the medium and low rainfall areas in Western Australia, Robert Sudmeyer, David Hall and Harvey Jones, Agriculture Western Australi

Climate in the Pilbara

The Pilbara is characterised by very hot summers, mild winters and low and variable rainfall. It is classified as hot desert in northern and inland areas and hot grasslands in the north-west. The Pilbara claims a number of climate records: seven of Western Australia’s top 10 hottest days, with Mardie recording the hottest day on record — 50.5 degrees Celsius (°C) most sunshine hours a day in Australia (more than 10 hours a day) second highest inter-annual variability in rainfall (second only to central Australia) the most cyclone-prone area along the Australian coastline. During summer and early autumn (December to March), average daily temperatures exceed 30°C across the region, with average daily maxima exceeding 35°C from October to March. In northern inland areas, such as Marble Bar, average maxima exceed 40°C during summer and temperatures exceeding 45°C are common. During the winter months (June to August), average temperatures are around 20°C across the region. Coastal areas have a smaller annual temperature range compared to inland areas and winter temperatures rarely drop below 10°C. Except for the upland areas of the Hamersley Ranges and south-eastern inland areas, there is minimal risk of frost. Rainfall is spatially and temporally variable. There is a general trend for annual rainfall to decline from 300–350 millimetres (mm) in the north-east to less than 250 mm in the south and west. However, elevated areas in the Hamersley Ranges average more than 500mm. Rainfall is greatest during summer and autumn and least during winter and spring. Rainfall in the eastern Pilbara is most influenced by tropical and monsoonal drivers, which are predominantly active in summer and autumn, while rainfall in the western Pilbara is also influenced by southern mid-latitude drivers, such as frontal systems, during autumn and winter. Tropical cyclones (TCs) cause the most extreme rainfall events and generate 25–34% of the total annual rainfall near the Pilbara coast and as much as 21% up to 450km inland. While TCs make a critical contribution to rainfall in the north-west, their inter-annual contribution to summer rainfall ranges from 0 to 86%. Historically, TCs have caused considerable damage and loss of life in the Pilbara, but modern design regulations ensure that buildings and other infrastructure are now far less susceptible to damaging winds. However, even the threat of a TC can cause substantial economic losses to the mining and offshore oil and gas industries through lost production or disruptions to shipping activities. Hot, dry and sunny conditions mean the Pilbara is subject to very high evaporative demand. Point potential evaporation represents the evapotranspiration that would occur from small, well-irrigated fields surrounded by non-irrigated land and exceeds 3000 millimetres per year (mm/y) over much of the Pilbara. The higher areas of the Hamersley Ranges are cooler and subject to greater summer cloud cover and so have the lowest evaporative demand. Potential evaporation is greatest during the summer months — averaging 10–14 millimetres per day (mm/d) — and least during winter, averaging 4–7mm/d. Over the last 40–60 years, average annual temperatures have increased across most of Western Australia (WA). In the Pilbara, temperatures increased most during winter and spring and cooled during autumn and summer. Warming during the largely cloudless winter and spring is in line with global trends, and summer cooling is likely caused by increasing summer rainfall and associated cloud cover over north-western Australia. Annual rainfall increased over most of the Pilbara, except in the west where it decreased. Rainfall intensity and number of rain days have also increased in the central and eastern parts and decreased in the west. A decline in autumn and winter rainfall over the western Pilbara has coincided with major shifts in the large-scale atmospheric circulation of the southern hemisphere. These changes include a southward shift in the subtropical ridge and the southern hemisphere westerly jet stream. Future climate Climate projections show very high confidence (see Appendix D) for substantial temperature increases to continue in the Pilbara, with the north-west of WA warming more than elsewhere in Australia. Annual average temperature is projected to increase by 0.6–1.5°C by 2030 for all emission scenarios and by 1.5–3.1°C and 3.1–5.6°C by 2090 for medium (RCP4.5) and high (RCP8.5) emission trajectories, respectively (Appendix C explains the emission trajectories). Annual rainfall is projected to remain largely unchanged to 2090 and there is high confidence that natural rainfall variability will remain the primary driver of rainfall changes to 2030. There is medium confidence that TCs will become less frequent in future but will increase in intensity. There is high confidence that potential evaporation will increase but only medium confidence in the magnitude of the change.https://library.dpird.wa.gov.au/bulletins/1224/thumbnail.jp