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WinMISKAM is evaluated from an emergency response perspective. Comparisons are made between ground level concentrations observed during selected Mock Urban Setting Test (MUST) field trials and predictions generated by the model. The model was driven by 5 min averaged on-site meteorological data, and used minimum grid spacing of 0.5 m in both the horizontal and vertical. The code was found to perform well, with 46% of all predictions (paired in time and space) and 83% of arc maxima predictions within a factor of two of observed concentrations. The model was found to perform better for neutral cases than stable cases with 27% of stable case predictions and 57% of neutral case predictions within a factor of two when compared in time and space.

Dimensional analysis is used to derive a simple model of private motorised mobility for any urban area based on detailed land use and travel pattern data from a large international sample of cities. This highlights the dependence of vehicle kilometres of travel on urban population and area and shows that despite time, social and cultural differences, urban areas behave in a systematic way. Private motorised mobility, although arising from local decisions, is in the mean determined by the structure of the urban environment. As private motorised mobility is based on vehicle kilometres of travel, which in turn is a surrogate for urban transportation emissions, urban air quality is directly linked to urban structure. This has implications for further research in urban air pollution and supports arguments in favour of the compact city.

A simple model is developed to analyse the surface energy balance from satellite observations for south-western Australia. This illustrates that the replacement of native vegitation with agriculture based on a winter growing annual species has led to a marked reduction in the sensible heat flux to the atmosphere during winter and spring. It is suggested that this reduction may be related to the observed decrease in winter rainfall observed throughout the agricultural region.

Land clearing for agricultural purposes in southwest Australia has created a landscape where a 750 km rabbit-proof fence separates 13 million hectares of croplands from the remnant native vegetation to the east. The Bunny Fence Experiment (BuFex) was conducted in the vicinity of the intended vermin-proof boundary in December 2005 and August 2007. The experiment examined the role of land cover change (LCC) on the preferential formation of clouds over the native vegetation that often terminates along the vermin-proof fence as well as the regional rainfall reduction observed in this region. Observations and numerical model analysis show that the formation and development of the west coast trough (WCT), which is a synoptic-scale feature that initiates spring and summertime convection, is impacted by land cover change and that the cloud fields induced by the WCT would extend further west in the absence of the LCC. The surface convergence patterns associated with the wintertime WCT circulation is substantially altered by LCC, due to changes in both WCT dynamics and surface aerodynamic roughness, leading to a rainfall decrease to the west of the rabbit fence. It is found that the LCC in southwest Australia is indeed responsible for preferential formation of clouds over native vegetation and contributes to the observed rainfall reduction in this region.”

A regional air pollution model, based on the solution of the Langevin equation, is developed and validated for both point and area sources. By incorporating the spatial and temporal variations in motor vehicle emissions for Perth, Western Australia, the model is able to reproduce the observed magnitude and spread of the urban plume.

Driving patterns influence and are influenced by land use patterns and other transport features. Traffic research, particularly driving cycle development has mainly focused on the pure engineering aspects of driving patterns to the neglect of this broader perspective. Consequently the interpretation of results and policy development on urban energy conservation and emissions abatement arising from driving cycle research have been seriously questioned. This study shows how it is possible to closely link instrumented vehicle research to an understanding of the wider urban system, i.e. the ecology of urban driving. To do this a methodology of sampling driving patterns in an urban area is developed and applied to Perth, Western Australia. This defines homogeneous areas within the city in terms of their activity intensity, modal split and social/economic status. The six areas developed provide not only a framework for sampling driving patterns but a way of demonstrating the urban ecological basis of driving patterns.

Observations show that the urban heat island in the atmospheric layer below roof level is most strongly developed during calm, cloudless conditions at night. This paper outlines two versions of a numerical model to describe the cooling of rural and street canyon surfaces under these conditions using surface thermal and radiative properties and the radiative geometry of the canyons. One version uses a full system of differential equations and the other the simpler force-restore approach. The two approaches are shown to be in general agreement and the output of the simpler model is shown to give a faithful representation of cooling of rural and urban surfaces, and therefore heat islands, when compared with field observations.

Hydrostatically dominated forced flow over the asymmetric topography of the Darling Scarp, Western Australia, is modelled using a hydrostatic numerical mesoscale model and compared with observations. Simulations reproduce the essential features of wave overturning and the development of a shooting hydraulic flow. This response is dependent on the wind profile but not on the existence of a critical level. the high backsheared environment leads to a high ratio of the Brunt-Vaisala frequency to wind speed throughout the profile, resulting in short wavelengths, high nonlinearity and overturning. With the ratio of the halfwidth of the topography to the boundary-layer depth being small, the flow fields are shown to be sensitive to the boundary layer.

Representative driving cycles across the Perth, Western Australia, metropolitan region illustrate a direct relationship to urban land use. Movement away from the central business district results in fewer traffic events, higher speeds, longer cruise periods and shorter stops. The consequent reduction in root mean square acceleration leads to a corresponding reduction in vehicle emission factors. Urban planning implications are pursued and highlight the importance of public transport as an option in reducing urban air pollution.

Previous studies have suggested that mesoscale processes are important in determining available wind energy potential in southern Australia. These effects are quantified by application of a numerical mesoscale model to the Swan coastal plain of Western Australia, illustrating that the wind power potential in this area is dominated by the sea breeze circulation and topographical influences. While sea breezes are a common feature of the summer climate, they are a significant source of wind energy only under weak synoptic flows, whereas mesoscale topographical effects are significant under all synoptic conditions.

As sowing dates are critical for appropriate yield forecasting, a national survey of Australian wheat farmers was undertaken. This revealed that wheat sowing generally takes 2-4 weeks to complete between the middle of May and the middle of June. Distinct regional differences occur in the way sowing is completed and these are related to soil and climatic effects. In Western Australia, sowing follows a more distinct `break in the season" and the midpoint of farm sowing is fairly uniform across cropping areas. As one progresses into south-eastern and then north-eastern cropping areas the spatial variability in sowing increases. The combination of fallowing practices, unreliable autumn rainfall, and heavier soils (that delay operations when conditions are wet or dry), all add to the variability in sowing date and sowing duration in north-eastern areas. The range of midpoint in sowing (between years) generally decreases as the progression is made from a farm, to a State, to a national scale. Reduced variability at a national scale is enhanced by broad-scale weather patterns causing sowing opportunities to contrast markedly on different sides of the country. During the 1980s, sowing progressed a day earlier per year at a national scale. The most pronounced changes occurred in Queensland and Western Australia, where a 2-3-week shift to earlier sowing was recorded. Coinciding with this was a trend in all areas to reduced or minimum tillage techniques. Late opening rains in South Australia restricted early sowing opportunities during this time.

A network of rainfall stations was selected across the Australian wheatbelt and monthly rainfall regressed with wheat yields from the surrounding shires for the period 1976-87. Yields were found to be strongly related to fluctuations in total rainfall amount and the seasonal distribution of rainfall through the year. These temporal relationships vary spatially and appear to be regulated by the water-holding capacity of regional soils. Sixteen agrometeorological zones were defined with similar rainfall-yield relationships. In all these, autumn rains that permit an early sowing, and finishing rains after July, are most important for higher yields. As the rainfall distribution becomes more winter-dominant, both crop yield variability and the usefulness of high winter rainfall decreases. Heavy rainfall in the month after sowing can have a negative effect in southern Australia, as plants are more prone to suffer potential yield losses from a wet soil profile. Waterlogging has a large negative effect in the south-west of Western Australia, such that the rainfall distribution can be more important than the rainfall amount. Rainfall-yield correlations are generally more positive in drier regions, and are enhanced by persistent rainfall anomalies between April and November during El Niño Southern Oscillation years.

A range of separate traffic and corridor studies from Perth are analyzed together with an international comparison of thirty-two cities to seek an answer to this question. The data suggest that free flowing traffic does not save energy or lower emissions overall in a city despite the apparently clear advantages for individual vehicles. The mechanisms for this in terms of travel distances, alternative modes and sub optimal vehicle usage are outlined together with the characteristics of cities where lower fuel use is apparent. Some implications for urban road project justification and traffic engineering practice are suggested.

Various methods are outlined for the analysis of mesoscale flow patterns and these are illustrated by application to the Adelaide (South Australia) urban area. They illustrate locally induced variations within the flow and also the seasonal transference of energy from synoptic sources in winter to the diurnal land-sea breeze system in the summer.

Observations of forced flow over the highly asymmetric topography of the Darling Scarp, Western Australia, are presented. These are typified by shallow surface gradient winds of 10-20 m s-1 with an inherent critical level aloft and a stable layer produced through nocturnal radiational cooling. The observations highlight a topographically induced hydraulic jump, lee waves or vertically propagating hydrostatic waves depending on the upwind stability and wind profile. The vertically propagating waves and hydraulic jump are observed to produce accelerated flow down the escarpment.

The spatial and temporal variation of particulate matter and air temperature was investigated over the inner Adelaide (South Australia) area. These observations illustrate the importance of the variability of the direction of light winds on the dispersion of particulate matter, the slow fall-off during the early hours of the morning in the level of pollutant arising from car emissions, and the need for profile measurements within the urban complex.

A simple surface energy budget model is developed and validated for an aboriginal rock art site in Western Australia. The thermal regime of the rock face is strongly dependent on the sky view factor for a vertical surface element and the sensible and latent heat fluxes are shown to be relatively unimportant. Using climatological data, the model is extended to form the basis for appropriate environmental management and conservation of the rock art.

A technique is developed for synthesising a statistically representative driving cycle for an urban area based on dynamic driving data collected by the chase car technique. The simulation procedure based on a “Knight's Tour” concept relies on an understanding of the dynamics of urban driving, in particular the observed tendency to maintain constant acceleration and deceleration rates. The final synthesised cycle is a representative real driving trace although the analysis raises questions about the level of resolution currently required for driving cycle work.