Hydrologic landscape regionalisation using deductive classification and random forests

Landscape classification and hydrological regionalisation studies are being increasingly used in ecohydrology to aid in the management and research of aquatic resources. We present a methodology for classifying hydrologic landscapes based on spatial environmental variables by employing non-parametric statistics and hybrid image classification. Our approach differed from previous classifications which have required the use of an a priori spatial unit (e.g. a catchment) which necessarily results in the loss of variability that is known to exist within those units. The use of a simple statistical approach to identify an appropriate number of classes eliminated the need for large amounts of post-hoc testing with different number of groups, or the selection and justification of an arbitrary number. Using statistical clustering, we identified 23 distinct groups within our training dataset. The use of a hybrid classification employing random forests extended this statistical clustering to an area of approximately 228,000 km2 of south-eastern Australia without the need to rely on catchments, landscape units or stream sections. This extension resulted in a highly accurate regionalisation at both 30-m and 2.5-km resolution, and a less-accurate 10-km classification that would be more appropriate for use at a continental scale. A smaller case study, of an area covering 27,000 km2, demonstrated that the method preserved the intra- and inter-catchment variability that is known to exist in local hydrology, based on previous research. Preliminary analysis linking the regionalisation to streamflow indices is promising suggesting that the method could be used to predict streamflow behaviour in ungauged catchments. Our work therefore simplifies current classification frameworks that are becoming more popular in ecohydrology, while better retaining small-scale variability in hydrology, thus enabling future attempts to explain and visualise broad-scale hydrologic trends at the scale of catchments and continents.

A decade of change in Australia’s DBA landscape

Purpose – The purpose of this paper is to examine the dynamics of the Doctorate of Business Administration (DBA) in Australia through the lens of a changing higher education landscape. The paper reflects on issues raised in a previous analysis of DBA programmes undertaken a decade ago, and highlights persistent challenges and emerging opportunities for professional Doctorate programmes in the Australian context.Design/methodology/approach – Interviews were undertaken with higher degree research directors, deans of graduate schools, and DBA programme directors from all 18 Australian institutions offering the DBA in 2013. Quantitative data on enrolments, accreditation requirements, course structures; and demographics are contextualised within a qualitative view of programme purposes, student and institutional motivations, rationales and concerns. Particular focus is given to perceptions of the difference between traditional research doctorates (PhDs) and professional doctorates, especially the DBA.Findings – In the decade from 2003 to 2013 DBA enrolments are down but enquiries are up, indicating unmet demand. There is a shift in the players, with some smaller, regional universities dramatically increasing their enrolments, and larger, traditional institutions exiting the space altogether. Significant changes in accreditation criteria have generated a perceptual shift: where DBAs previously suffered from “academic snobbery” regarding their legitimacy, this perception is being challenged by standards which require DBA equivalence with a PhD. This shift in standards has also created some confusion amongst supervisors and candidates.Originality/value – There is limited research into the DBA award or its candidates, and academic literature is generally silent on DBA supervision. This piece of research, one of very few that specifically examine the DBA, reflects on the past decade, analyses the present context and identifies emerging issues for the delivery of DBA programmes in Australia.

Does fire influence the landscape-scale distribution of an invasive mesopredator?

Predation and fire shape the structure and function of ecosystems globally. However, studies exploring interactions between these two processes are rare, especially at large spatial scales. This knowledge gap is significant not only for ecological theory, but also in an applied context, because it limits the ability of landscape managers to predict the outcomes of manipulating fire and predators. We examined the influence of fire on the occurrence of an introduced and widespread mesopredator, the red fox (Vulpes vulpes), in semi-arid Australia. We used two extensive and complimentary datasets collected at two spatial scales. At the landscape-scale, we surveyed red foxes using sand-plots within 28 study landscapes - which incorporated variation in the diversity and proportional extent of fire-age classes - located across a 104 000 km2 study area. At the site-scale, we surveyed red foxes using camera traps at 108 sites stratified along a century-long post-fire chronosequence (0-105 years) within a 6630 km2 study area. Red foxes were widespread both at the landscape and site-scale. Fire did not influence fox distribution at either spatial scale, nor did other environmental variables that we measured. Our results show that red foxes exploit a broad range of environmental conditions within semi-arid Australia. The presence of red foxes throughout much of the landscape is likely to have significant implications for native fauna, particularly in recently burnt habitats where reduced cover may increase prey species' predation risk.

Granitic coastal geomorphology: Applying integrated terrestrial and bathymetric LiDAR with multibeam sonar to examine coastal landscape evolution

Coasts composed of resistant lithologies such as granite are generally highly resistant to erosion. They tend to evolve over multiple sea level cycles with highstands acting to remove subaerially weathered material. This often results in a landscape dominated by plunging cliffs with shore platforms rarely occurring. The long-term evolution of these landforms means that throughout the Quaternary these coasts have been variably exposed to different sea level elevations which means erosion may have been concentrated at different elevations from today. Investigations of the submarine landscape of granitic coasts have however been hindered by an inability to accurately image the nearshore morphology. Only with the advent of multibeam sonar and aerial laser surveying can topographic data now be seamlessly collected from above and below sea level. This study tests the utility of these techniques and finds that very accurate measurements can be made of the nearshore thereby allowing researchers to study the submarine profile with the same accuracy as the subaerial profile. From a combination of terrestrial and marine LiDAR data with multibeam sonar data, it is found that the morphology of granite domes is virtually unaffected by erosion at sea level. It appears that evolution of these landscapes on the coast is a very slow process with modern sea level acting only to remove subaerially weathered debris. The size and orientation of the joints determines the erosional potential of the granite. Where joints are densely spaced (<2 m apart) or the bedrock is highly weathered can semi-horizontal surfaces form.

The influence of non-climate predictors at local and landscape resolutions depends on the autecology of the species

Species distribution models have come under criticism for being too simplistic for making robust future forecasts, partly because they assume that climate is the main determinant of geographical range at large spatial extents and coarse resolutions, with non-climate predictors being important only at finer scales. We suggest that this paradigm might be obscured by species movement patterns. To explore this we used contrasting kangaroo (family Macropodidae) case studies: two species with relatively small, stable home ranges (Macropus giganteus and M.robustus) and three species with more extensive, adaptive ranging behaviour (M.antilopinus, M.fuliginosus and M.rufus). We predicted that non-climate predictors will be most influential to model fit and predictive performance at local spatial resolution for the former species and at landscape resolution for the latter species. We compared residuals autocovariate - boosted regression tree (RAC-BRT) model statistics with and without species-specific non-climate predictors (habitat, soil, fire, water and topography), at local- and landscape-level spatial resolutions (5 and 50km). As predicted, the influence of non-climate predictors on model fit and predictive performance (compared with climate-only models) was greater at 50 compared with 5km resolution for M.rufus and M.fuliginosus and the opposite trend was observed for M.giganteus. The results for M.robustus and M.antilopinus were inconclusive. Also notable was the difference in inter-scale importance of climate predictors in the presence of non-climate predictors. In conclusion, differences in autecology, particularly relating to space use, may contribute to the importance of non-climate predictors at a given scale, not model scale per se. Further exploration of this concept across a range of species is encouraged and findings may contribute to more effective conservation and management of species at ecologically meaningful scales. © 2014 Ecological Society of Australia.

I-Face

The small format nature of the annual exhiition provides a oportunity to experiment formally, specifically with ways to entangle subject and space/environment. Supplementary to primamry research focus on Landscape and Consciousness

Indelible 4

The painting is one of a series that responds to the landscape of central Australia and extends on my interest in the interaction of matter and the emergence of new insights that is inherent to the creative process

Indelible 3

This painting responds to the landscape of Central Australia and extends on my enquiry into the interaction of matter and the emergence of new insights inherent to creative practice

Indelible 2

This painting responds to the landscape of Central Australia and extends on my enquiry into the interaction of matter and the emergence of new insights inherent to creative practice

Indelible 1

This painting responds to the landscape of Central Australia and extends on my enquiry into the interaction of matter and the emergence of new insights inherent to the creative process

Towards a theory of landscape iconoclasm

The destruction of Indigenous rock art sites in the Pilbara district in Western Australia has become a natural sight within the mining landscape of the area. Whilst much of the destruction is explained as acts of vandalism and as a result of the industrial activities that are propelling the Australian economy, I claim that a new theory of iconoclasm is needed to explain fully this disastrous example of heritage conservation. Henceforth, in order to explain the destruction of the Murujuga/Burrup Peninsula petroglyphs, the largest archaeological site in the world, this paper develops the theory of landscape iconoclasm. This theory states that the destruction of Indigenous landscapes can be compared to the destruction of religious images, by analysing the inherent symbolic functions of iconoclasm, together with those of heritage, the better to elucidate the state of affairs in the Murujuga/Burrup Peninsula. Furthermore, by drawing from Aboriginal mythology and art-historical and anthropological theories, the theory of landscape iconoclasm is able to explain the destruction of archaeological sites within a framework that falls outside prevalent discourses of heritage.