Otago University Research Archive
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NZDep2018 analysis of census 2018 variables - DHB04: Counties Manukau
No full textFor further information about data sources, interpretation of the graphs, and cautions, please see the separate Introduction Chapter
All data relating to the 2018 census is provided by Stats NZ, https://www.stats.govt.nz/
NZDep2018 analysis of census 2018 variables - DHB05: Waikato
No full textFor further information about data sources, interpretation of the graphs, and cautions, please see the separate Introduction Chapter
All data relating to the 2018 census is provided by Stats NZ, https://www.stats.govt.nz/
NZDep2018 analysis of census 2018 variables - TA013: Waikato District
No full textFor further information about data sources, interpretation of the graphs, and cautions, please see the separate Introduction Chapter
All data relating to the 2018 census is provided by Stats NZ, https://www.stats.govt.nz/
NZDep2018 analysis of census 2018 variables - TA017: Waipa District
No full textFor further information about data sources, interpretation of the graphs, and cautions, please see the separate Introduction Chapter
All data relating to the 2018 census is provided by Stats NZ, https://www.stats.govt.nz/
NZDep2018 analysis of census 2018 variables - TA019: Otorohanga District
No full textFor further information about data sources, interpretation of the graphs, and cautions, please see the separate Introduction Chapter
All data relating to the 2018 census is provided by Stats NZ, https://www.stats.govt.nz/
Assessment of migration barriers in the eastern Otago region: Perched road culverts, climbing galaxiids and non-migratory galaxiid conservation
No full textNew Zealand’s diadromous fish populations face vast networks of road culverts that often limit upstream dispersal as a function of efficient hydrological design. Migration barriers, such as perched pipe culverts, fragment and isolate viable stream habitat from recruitment by overcoming migratory adaptations of fish, inevitably eroding populations through genetic loss. This study addressed several concerns of conservation managers in the eastern Otago region through examination of impassable perched pipe culvert impacts on local fish distributions, as well as trialling perched migration barriers in the laboratory and field in order to protect a threatened non-migratory galaxiid population from an invasive species. The latter trial was found to have great promise as a freshwater conservation management tool.
The interaction between poor road culvert design and fish dispersal has been examined across New Zealand’s differing landscapes. In eastern Otago, commercial forestry plantations provided homogenous land use type and pipe culvert design to examine perched pipe culvert prevalence and fish distribution in relation to pipe culverts as seen in Chapter Two. By using a unique approach identifying pipe culverts as passable or impassable a priori, based on previous fish passage understanding and research, the relationship between fish distribution and culverts could be examined despite inherently dynamic interactions between fish migratory adaptations and culvert characteristics. Surveys found just over fifty percent of pipe culverts were perched to some degree, and upon analysis that a negative relationship existed between species richness and fish abundance above versus below pipe culverts. The findings galvanise current understanding of the limiting effects of pipe culverts on upstream fish migration and identify the scale of perched culvert prevalence in commercial forestry plantations of the eastern Otago region.
Abundance trends, although statistically inconclusive but scientifically supported, affirm that impassable pipe culverts likely have a limiting/barrier effect on the dispersal and migration of kōaro (Galaxias brevipinnis). The climbing migratory adaptations which kōaro rely on to navigate in-stream obstacles were examined in Chapter Three. The relationship between climbing success and juvenile kōaro size was trialled in a controlled environment and revealed a significant trend in the size of juvenile kōaro climbers that were successful at navigating a simulated migration barrier. Disrupting the wetted margin, and thus hydrological connectivity, through the use of a perched barrier proved totally effective at halting juvenile kōaro climbing.
Kōaro are considered an invasive threat to populations of the rare non-migratory dusky galaxias (Galaxias pullus) in several tributaries of the upper Waipori River in eastern Otago. Attempts by the Department of Conservation to install migration barriers on a research weir to limit kōaro recruitment into a dusky galaxias stronghold population had proven unsuccessful. Chapter Four documents the development and deployment of a perched aluminium migration barrier which continued to be extremely successful over a period of several years at halting juvenile kōaro recruitment as confirmed by electrofishing and kōaro relocation data pre and post installation. This system provides conservation managers with a tool to protect non-migratory galaxiids across New Zealand that are at risk of juvenile kōaro invasion, and for the protection of historic habitat for non-migratory galaxiid translocation.
Investigation into kōaro migratory capabilities also raised new questions about the interactions between form and function of climbing adaptations and how these may have influenced the evolutionary ecology of ancestral climbing galaxiids in response to geological processes. Discussions regarding the complexity of kōaro migration as a dynamic process of timing, growth and distance are also presented.
Understanding the mechanisms by which perched pipe culverts limit upstream fish migration, and on which migratory fish species rely, allows for conservation managers to improve fish passage or control invasive fish species encroachment, both with the purpose of conserving endangered species and in-stream habitats. Overall, critical thinking and understanding of fish migratory adaptations, both in a natural setting and a controlled environment, has proven a robust method in developing a useful conservation tool for endangered species isolation management while working closely alongside front line conservation managers
NZDep2018 analysis of census 2018 variables - TA038: Rangitikei District
No full textFor further information about data sources, interpretation of the graphs, and cautions, please see the separate Introduction Chapter
All data relating to the 2018 census is provided by Stats NZ, https://www.stats.govt.nz/
Agents of movement: Intelligence in space-time from mapping to causality
No full textRepresenting dynamic spatial phenomena is a long-standing goal within Geospatial Information Science (GIScience). Geometric positions are fundamental elements of any spatiotemporal process, such that a significant body of related studies has been dedicated to modelling the autonomous changes of geometries over time (movement). There has been a ‘causal revolution’ in computer science, economics, epidemiology, and social sciences, powered by large and complex spatiotemporal data. There is accordingly a need to expand the objectives of movement studies from descriptive models, data mining and pattern recognition to explanations of the underlying causes of movement.
From both a practical and theoretical standpoint, progress in developing approaches for filling the gap of explanatory movement models should be founded on a conceptual model. A short review based on a movement analysis informed examination of advantages and critiques concluded on the need for an integration of two approaches in a causality-led conceptual model for agents: simulation-based (i.e. agent-based modelling) and data-driven (i.e. graphical causal modelling). To achieve this integration, three conceptual levels of abstraction were proposed to frame an agent-based representation of movement decision-making processes: ‘attribute’, (environmental) ‘actor’, and ‘autonomous agent’. These, in combination with three temporal, spatial, and spatiotemporal general forms of observations distinguish nine (3x3) representation typologies of movement data within the agent framework. In addition to these nine representation typologies, there are three levels of cognitive reasoning about spatiotemporal phenomena: ‘association’, ‘intervention’, and ‘counterfactual’. Together, these make for 27 possible types of operation embedded in a conceptual cube with the level of abstraction, type of observation, and degree of cognitive reasoning forming the three axes.
The first application of the conceptual framework was to build and test an agent-based model that was constrained in time and space with clearly articulated rules. The movement of football players was modelled as a design guideline for a vector-agent model. The simulation was submitted to an accreditation process to show how agent-based movement simulations can contribute to our understanding of movement and how they can potentially produce causally relevant evidence.
Informed by the previous approach, an empirically-based implementation was developed to accommodate graphical causal models and their concepts within movement studies (i.e. the ‘association’, ‘intervention’ and ‘counterfactual’ levels of cognitive reasoning in the conceptual cube). This involved a three-level process for inferring quantitative causal evidence from passive observations. A directed acyclic graph was designed and computed on a generated movement dataset of football players to represent the extent to which a correct causal structure of an act of movement can be inferred. The results showed that, given adequate evidence about the probability distribution of the variables involved, graphical causal models could handle the complexity within the causal structure underlying a movement decision-making process.
This thesis has adapted causal thinking in computational movement analysis and put forward a conceptual data-driven agent architecture. A physical vector-agent architecture that shows how an autonomous moving agent, equipped with highly abstracted causal knowledge, compartmentalising its perceptions of the environment and its reasoning for movement, was demonstrated and tested. Issues regarding the implementation of this model in other application domains (e.g. animal movement) were recognised as the next challenge towards causal analysis across movement studies, addressing questions of generalisability and portability. The proposed conceptual model and approach to inferring causality shows one approach to achieving these goals
There is always a reason: Cognitive and experiential impacts on reasoned attitudes
No full textWhile the pervasive notion that reasoning leads to optimal judgments seems commonsensical, some research has shown that reasoning sometimes causes suboptimal outcomes, suggesting that the relationship between reasons and judgment is more complicated than classically assumed. While cognitive theories ascribe the mechanisms of reasoned judgment to the reason content (e.g., quality and number), “ease of retrieval” research reveals an important role of reasoning experience; however, neither provides a complete account, hinting at missing links among cognitive and experiential factors. In this thesis, I report eight studies examining the relationships between reason quality and reasoning difficulty, and the conditions under which they predict attitudes and decisional satisfaction. Chapter 2 reports three studies showing that reasoning difficulty and perceived reason quality covary in the ease of retrieval paradigm: increasing numbers of reasons get increasingly difficult to generate, but also decrease in perceived quality, and it is quality rather than difficulty that uniquely predicts attitudes. Chapters 3 and 4 consider the causal relationship between difficulty and quality, and their downstream effect on attitude change. The results of four studies are most consistent with an interference hypothesis, such that experienced effort disrupts participants’ ability to cognitively elaborate on reasons, causing strong reasons to be judged as less persuasive, and weak reasons as more persuasive. The disrupting effects on perceived quality and attitude change are mitigated when people are highly motivated. Finally, Chapter 5 applies these insights to the issue of choice satisfaction, showing higher satisfaction after reasoning with ease, but adding more reasons neither increases nor decreases it. In sum, the findings show how the impacts of reasoning involve a complicated interplay among cognitive and experiential factors, ability and motivation to reason, and the contexts in which they are applied. Implications and applications of the findings, e.g., in advertising and deceptive message, limitations and future research venues are discussed
New Zealand Deprivation Index 2018 - TA55: Buller District
No full textFor further information about data sources, interpretation of the graphs, and cautions, please see the separate Introduction Chapter
All data relating to the 2018 census is provided by Stats NZ, https://www.stats.govt.nz/