Hydrological hazard assessment for irrigated agriculture in the Irwin focus area

The Midlands groundwater and land assessment project aimed to identify 2000–3000 hectare precincts suitable to develop intensive irrigated horticulture. The primary focus area was at Irwin, where the Department of Water and Environmental Regulation investigated groundwater resources and the Department of Primary Industries and Regional Development undertook a multi-faceted site assessment. This report describes the hydrological hazards assessment for the Irwin focus area. The Irwin focus area is located on fertile loam and clay flats associated with the Irwin River. In the east, it encompasses the Irwin River valley floor and the western boundary loops to the south of the Irwin River to capture an area of alluvial clays. The Gingin Scarp forms a boundary between the east and west parts of the focus area. We used groundwater data from resource condition monitoring in the Arrowsmith Hydrozone to assess the hydrological hazards in the Irwin focus area and guide more intensive field investigations. We undertook a shallow drilling program to investigate the profile and to sample and monitor the watertable in the western part of the Irwin focus area. Monitoring bores were established at 13 sites on the alluvial clay flats. The shallow drilling program was complemented with ground-based electromagnetic surveys. A vehicle-mounted system was developed to record electrical conductivity measurements from Geonics™ EM38 and EM31 instruments. Historical groundwater level monitoring in the Irwin River valley indicates consistently rising groundwater levels east of the Gingin Scarp in the Arrowsmith Hydrozone. This trend and shallow depth to groundwater poses a significant risk of dryland salinity developing in this landscape. This existing hydrological hazard, rising groundwater and salinity, makes the eastern part of the focus area unsuitable for irrigated horticulture. West of the Gingin Scarp, the soil profile under the alluvial flats that extend south of the Irwin River is dominated by stiff, moist, grey clay that becomes red-brown or mottled brown and pale grey clay with depth. While the surface soils are not salt-affected, there is significant salt storage at depth, starting from about 3m to about 7–10m. Since groundwater is not rising in this area the regolith salt storage is not a hazard for dryland agriculture. However, if irrigation water is applied and groundwater rises, it will become a significant hazard. The hydraulic properties of the alluvial clays could not be closely observed during the investigation because of the absence of recharge due to low rainfall. However, the drill cuttings of heavy, moist clay indicate that there is low hydraulic conductivity or permeability. If the surface soils were to become saline from irrigation, they would likely remain saline because of the limited leachability of the clays

Testing carbon farming opportunities for salinity management

An emerging prospect for farm revenue from revegetation of saline and other lands that are marginal or non-productive for agriculture is the sale of carbon credits. Australian Government schemes for carbon credits include the Carbon Farming Initiative (CFI) and the proposed Emissions Reduction Fund (ERF) Therefore, this study aimed to assess the potential for woody vegetation (trees and shrubs) established on and around salt-affected lands in the Northern Agricultural Region (NAR) to remove carbon dioxide from the atmosphere and store (sequester) the carbon in new growth. Revegetation plantings on six farms were selected for the study after the landowners expressed interest in participating in the study. Criteria for selection included: minimum of 5 ha planted on and around salt-affected land; a variety of native trees and shrub species planted; and that the plantings must be at least 10 years old. Across the six farms a total of nine sites were selected for the study. The estimates of carbon stocks in species and sites were projected forwards and backwards from the measurement ages (11 - 22 years)to age 15 years to \u27age standardise\u27 the results and facilitate comparison between species and sites. This was done using the national carbon accounting model, FullCAM

SCN5A allelic expression imbalance in African-Americans heterozygous for the common variant p.Ser1103Tyr

<p>Abstract</p> <p>Background</p> <p>Heterozygous and homozygous carriers of <it>SCN5A</it>-p.Ser1103Tyr, a common genetic variant with functional effects among African-Americans, have an increased risk of sudden death. We hypothesized that some heterozygous carriers may have unequal expression of wild-type and variant alleles and secondarily that predominance of the variant gene copy could further increase risk for sudden death in this population.</p> <p>Methods</p> <p>We quantified allele-specific expression of <it>SCN5A</it>-p.Ser1103Tyr by real-time reverse-transcription polymerase chain reaction (RT-PCR) in heart tissue from heterozygous African-American infants, who died from sudden infant death syndrome (SIDS) or from other causes, to test for allelic expression imbalance.</p> <p>Results</p> <p>We observed significant allelic expression imbalance in 13 of 26 (50%) African-American infant hearts heterozygous for <it>SCN5A</it>-p.Ser1103Tyr, and a significant (p < 0.0001) bimodal distribution of log₂allelic expression ratios. However, <b>t</b>here were no significant differences in the mean log₂allelic expression ratios in hearts of infants dying from SIDS as compared to infants dying from other causes and no significant difference in the proportion of cases with greater expression of the variant allele.</p> <p>Conclusions</p> <p>Our data provide evidence that <it>SCN5A </it>allelic expression imbalance occurs in African-Americans heterozygous for p.Ser1103Tyr, but this phenomenon alone does not appear to be a marker for risk of SIDS.</p

Hydrogeology of the Gillingarra Palaeochannel

Previous groundwater investigations had identified the presence of palaeochannel sediments under the Capitela Valley in the Perth Basin, about 25 kilometres south-west of Moora. The sediments of this Capitela Palaeochannel were thought to form a discrete aquifer of good quality groundwater suitable for agriculture. To improve our understanding of the Capitela Palaeochannel, its distribution, water quality and potential as a groundwater resource, we undertook an airborne electromagnetic (AEM) geophysical survey of the area in December 2012. This led to the discovery of a palaeochannel located in the Darling Range between Gillingarra and New Norcia, and we named this the Gillingarra Palaeochannel. The Gillingarra Palaeochannel warranted further investigation so we undertook a drilling program to validate the geophysical interpretation and to obtain information about the aquifer’s hydraulic and geochemical properties. As part of the program, we installed 16 monitoring bores and a production bore at nine sites, during October 2013 to February 2014. Drilling results show that the Gillingarra Palaeochannel is up to 197 metres (m) deep, up to 1.18km wide and at least 18km long, and is mostly composed of coarse sand. We conducted test pumping of the production bore to estimate the Gillingarra Palaeochannel’s parameters and potential bore yields. The bore produced about 700 kilolitres per day of brackish quality water — 307 millisiemens per metre electrical conductivity, or 1700 milligrams per litre total dissolved solids — suitable for livestock watering. We estimate the annual recharge to the aquifer to be about 0.85 gigalitres per year and the brackish groundwater in storage to be 4.6GL. We discovered that, although they seem to be aligned, the Gillingarra Palaeochannel is not connected to the shallower Capitela Palaeochannel. The rising groundwater levels and salinity developing along the Bindoon–Moora Road and Midlands rail line is due to discharge from the Gillingarra Palaeochannel. Despite not being an extensive groundwater resource, this aquifer will be able to provide a valuable local source for livestock watering and some agriculture for the Gillingarra – New Norcia area

Hydrological hazard assessment for irrigated agriculture in the Irwin focus area

The Midlands groundwater and land assessment project aimed to identify 2000–3000 hectare precincts suitable to develop intensive irrigated horticulture. The primary focus area was at Irwin, where the Department of Water and Environmental Regulation investigated groundwater resources and the Department of Primary Industries and Regional Development undertook a multi-faceted site assessment. This report describes the hydrological hazards assessment for the Irwin focus area. The Irwin focus area is located on fertile loam and clay flats associated with the Irwin River. In the east, it encompasses the Irwin River valley floor and the western boundary loops to the south of the Irwin River to capture an area of alluvial clays. The Gingin Scarp forms a boundary between the east and west parts of the focus area. We used groundwater data from resource condition monitoring in the Arrowsmith Hydrozone to assess the hydrological hazards in the Irwin focus area and guide more intensive field investigations. We undertook a shallow drilling program to investigate the profile and to sample and monitor the watertable in the western part of the Irwin focus area. Monitoring bores were established at 13 sites on the alluvial clay flats. The shallow drilling program was complemented with ground-based electromagnetic surveys. A vehicle-mounted system was developed to record electrical conductivity measurements from Geonics™ EM38 and EM31 instruments. Historical groundwater level monitoring in the Irwin River valley indicates consistently rising groundwater levels east of the Gingin Scarp in the Arrowsmith Hydrozone. This trend and shallow depth to groundwater poses a significant risk of dryland salinity developing in this landscape. This existing hydrological hazard, rising groundwater and salinity, makes the eastern part of the focus area unsuitable for irrigated horticulture. West of the Gingin Scarp, the soil profile under the alluvial flats that extend south of the Irwin River is dominated by stiff, moist, grey clay that becomes red-brown or mottled brown and pale grey clay with depth. While the surface soils are not salt-affected, there is significant salt storage at depth, starting from about 3m to about 7–10m. Since groundwater is not rising in this area the regolith salt storage is not a hazard for dryland agriculture. However, if irrigation water is applied and groundwater rises, it will become a significant hazard. The hydraulic properties of the alluvial clays could not be closely observed during the investigation because of the absence of recharge due to low rainfall. However, the drill cuttings of heavy, moist clay indicate that there is low hydraulic conductivity or permeability. If the surface soils were to become saline from irrigation, they would likely remain saline because of the limited leachability of the clays

Testing carbon farming opportunities for salinity management

An emerging prospect for farm revenue from revegetation of saline and other lands that are marginal or non-productive for agriculture is the sale of carbon credits. Australian Government schemes for carbon credits include the Carbon Farming Initiative (CFI) and the proposed Emissions Reduction Fund (ERF) Therefore, this study aimed to assess the potential for woody vegetation (trees and shrubs) established on and around salt-affected lands in the Northern Agricultural Region (NAR) to remove carbon dioxide from the atmosphere and store (sequester) the carbon in new growth. Revegetation plantings on six farms were selected for the study after the landowners expressed interest in participating in the study. Criteria for selection included: minimum of 5 ha planted on and around salt-affected land; a variety of native trees and shrub species planted; and that the plantings must be at least 10 years old. Across the six farms a total of nine sites were selected for the study. The estimates of carbon stocks in species and sites were projected forwards and backwards from the measurement ages (11 - 22 years)to age 15 years to \u27age standardise\u27 the results and facilitate comparison between species and sites. This was done using the national carbon accounting model, FullCAM