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The Upper Hunter Valley is a major coal mining area in New South Wales (NSW), Australia. Due to the ongoing increase in mining activities, PM10 (air-borne particles with an aerodynamic diameter less than 10 micrometres) pollution has become a major air quality concern in local communities. The present study was initiated to quantitatively examine the spatial and temporal variability of PM10 pollution in the region. An earlier paper of this study identified two air quality subregions in the valley. This paper aims to provide a holistic summarisation of the relationships between elevated PM10 pollution in two subregions and the local- and synoptic-scale meteorological conditions for spring and summer, when PM10 pollution is relatively high. A catalogue of twelve synoptic types and a set of six local meteorological patterns were quantitatively derived and linked to each other using the self-organising map (SOM) technique. The complex meteorology–air pollution relationships were visualised and interpreted on the SOM planes for two representative locations. It was found that the influence of local meteorological patterns differed significantly for mean PM10 levels vs. the occurrence of elevated pollution events and between air quality subregions. In contrast, synoptic types showed generally similar relationships with mean vs. elevated PM10 pollution in the valley. Two local meteorological patterns, the hot–dry–northwesterly wind conditions and the hot–dry–calm conditions, were found to be the most PM10 pollution conducive in the valley when combined with a set of synoptic counterparts. These synoptic types are featured with the influence of an eastward migrating continental high-pressure system and westerly troughs, or a ridge extending northwest towards coastal northern NSW or southern Queensland from the Tasman Sea. The method and results can be used in air quality research for other locations of NSW, or similar regions elsewhere. [ABSTRACT FROM AUTHOR]

There is an opportunity to reduce methane emissions from Australian, open pit, metallurgical coal (MC) mines and substantially reduce the carbon intensity of a high-value Australian export industry. MC is critical to the production of steel products and is essential to meet international urbanisation and energy system transformation goals. Initial research on this topic, outlined the application of subterranean barriers in coal mining towards the reduction of gas influx and whole-of-life coal mine methane (CMM) emissions in underground applications. Initially, the technology lacked economic viability for a majority of cases and especially after carbon pricing was eliminated in 2014. Today, with the imperative for the industry to reduce emissions, the technology becomes significant in its potential for emissions reduction for both underground and open-cut coal mines. The basis of barriers is similar to naturally occurring barriers (i.e., igneous intrusions or dikes) that have shown effective separation of drained and undrained mine works (as observed in adjoining mines in Central Queensland). Barriers have also been applied in the environmental, civil engineering and oil and gas industries, to manage or restrict subterranean flow patterns or contain contaminants. In this case, subterranean barriers are being implemented in conjunction with mine pre-drainage to reduce methane emissions from an open pit, MC mine. In addition, barriers can be used in underground mining operations.to improve mine pre-drainage and safety as well as reduce methane emissions. This paper describes the design, execution, and evaluation workflows and the relative importance of variables required for a barrier implementation in subterranean applications for open-cut and underground mining applications. This paper details the results of ongoing planning and modelling to implement and assess a barrier application for reducing gas migration from unmined in-seam or underground mine sections into open-cut MC mining operations. Finally, this paper builds on previous research and available technologies and is complementary to current pre-drainage for surface or underground mining operations. Barrier implementation in conjunction with the beneficial use of gas provides a working framework to reduce mine emissions toward necessary methane reductions by 2030. • Reducing methane emissions from open pit and underground metallurgical coal mines is required to reduce the carbon intensity of the industry. • The design, execution, evaluation, and verification steps for subterranean barrier placements in coal mines are presented. • Example models show the benefits of barrier placements in reducing overall emissions from open-cut and underground coal mines. • The technology is dependent on the permeability and anisotropy of the coals, and the process improves with additional and external drainage. [ABSTRACT FROM AUTHOR]