title: An analysis of perceptual errors in perspective displays

authors: Luther, Rebecca E.

abstract: Display dimensionality 1s one of the most debated issues m the design of cockpit-based displays of air traffic information. Many practitioners agree that presenting air traffic information on an integrated 30 display is preferable, when compared to presenting it on a 20 planar or co-planar display. However, research has shown that operators make errors in estimating the location of objects in 30 displays. This may be because of perceptual distortions caused by the geometric parameters used to generate the image. However, despite the issues identified regarding the locating of objects, some studies have found other performance advantages associated with these 30 displays. Therefore, it seems that attempts should be made to minimise perceptual biases so that these displays can be utilised to present integrated information in 30 environments. The aim of this thesis was to develop a model of distance estimation errors in perspective displays. It was hypothesised that many of the perceptual errors observed in perspective displays, such as azimuth and inter-object distance estimation errors, were related to observers wrongly estimating the distance between themselves and objects in the virtual world. Four experiments examining inter-object distance estimation were conducted. Participants were required to set a perspective image of a box to represent a perfect cube (requiring them to make a distance estimation scaled relative to the frontoparallel plane). Results showed that participants made inter-object distance estimation errors that increased as the distance between the observer and the objects in the display increased. Based on these results, two models explaining interobject distance estimation errors were developed. The first model postulated that participants underestimated the distance between themselves and objects in the display. The second model suggested that participants used 20 ( on-screen) cues to set the box to a cube. These models were applied to azimuth estimation errors observed in studies of perspective displays. It was found that while azimuth estimation error could only be partially modelled as a distance perception error, it could be explained to a greater extent by applying a strategy based on the 20 (on-screen) image. The findings of this study indicated that either distance estimation errors or 20 strategies could account for inter-object distance estimation errors in perspective displays.

text: An analysis of perceptual errors in perspective displays Display dimensionality 1s one of the most debated issues m the design of cockpit-based displays of air traffic information. Many practitioners agree that presenting air traffic information on an integrated 30 display is preferable, when compared to presenting it on a 20 planar or co-planar display. However, research has shown that operators make errors in estimating the location of objects in 30 displays. This may be because of perceptual distortions caused by the geometric parameters used to generate the image. However, despite the issues identified regarding the locating of objects, some studies have found other performance advantages associated with these 30 displays. Therefore, it seems that attempts should be made to minimise perceptual biases so that these displays can be utilised to present integrated information in 30 environments. The aim of this thesis was to develop a model of distance estimation errors in perspective displays. It was hypothesised that many of the perceptual errors observed in perspective displays, such as azimuth and inter-object distance estimation errors, were related to observers wrongly estimating the distance between themselves and objects in the virtual world. Four experiments examining inter-object distance estimation were conducted. Participants were required to set a perspective image of a box to represent a perfect cube (requiring them to make a distance estimation scaled relative to the frontoparallel plane). Results showed that participants made inter-object distance estimation errors that increased as the distance between the observer and the objects in the display increased. Based on these results, two models explaining interobject distance estimation errors were developed. The first model postulated that participants underestimated the distance between themselves and objects in the display. The second model suggested that participants used 20 ( on-screen) cues to set the box to a cube. These models were applied to azimuth estimation errors observed in studies of perspective displays. It was found that while azimuth estimation error could only be partially modelled as a distance perception error, it could be explained to a greater extent by applying a strategy based on the 20 (on-screen) image. The findings of this study indicated that either distance estimation errors or 20 strategies could account for inter-object distance estimation errors in perspective displays.

year: 2004

title: Adaptation of New Zealand dairy farms to climate change: An integrated, farm-level analysis

authors: Kalaugher, Electra

subjects: interdisciplinary research

abstract: The dairy sector is a cornerstone of the New Zealand economy and as such, it is important to understand the ways in which it is likely to be affected by climate change, whether it will need to adapt, and if so, how this can best be achieved. The overall goal of this research was to analyse potential strategies for New Zealand dairy farms to adapt to projected climate change. For this purpose, an integrated biophysical and socio-economic research framework was developed. Drawing on recognised frameworks for the analysis of climate change adaptation, together with systems analysis methodologies, the framework sets out an integrated process for analysing potential adaptation strategies at farm level.

Six case study farms were selected for the analysis, representing major dairying regions in New Zealand and covering a range of climatic zones and management approaches. The farmers selected were experienced and respected operators, in order to draw on their knowledge of farming systems resilience. Qualitative social research provided insights into the way the farmers saw their farming systems and how climate change issues were placed in the context of other challenges facing the farmers. It also provided a farmer perspective on some of the driving forces that influence the current trajectories of New Zealand dairy systems, in particular their concerns around the effects of environmental regulation and changes in farm structure, which may affect the future adaptive capacity of their farming systems. 

The next step in the analysis was to model the farms in the DairyNZ Whole Farm Model (WFM) under dynamically downscaled climate change scenarios provided by the National Institute of Water and Atmospheric Research (NIWA). This showed significant potential for some adaptations to mitigate the projected impacts of climate change. For example, making and feeding out more silage, and changing the pasture species modelled, showed benefits for nearly all farming systems. However, there were limitations in the capacity of the model to accurately represent the on-farm challenges of implementing such adaptations. Feedback from the farmers highlighted the limitations, as well as the potential value of such modelling work, emphasising the importance of assessing such research in context.

A second round of modelling work was carried out based on the suggestions of individual farmers for their own farms. The suggestions made by farmers were predominantly incremental, rather than transformational adaptations, reflecting the farmer’s positive assessment of the current level of resilience in their farming systems, but also reflecting their operational and personal constraints.  Modelling under present conditions and future climate showed that many of the adaptations did mitigate the impacts of climate change. However, there was still a largely negative impact compared to the same adaptations carried out under the baseline (current) climate. This implies that ongoing work, innovation and technological adjustments will be required to optimise these farming systems under future climate conditions.

For both incremental and transformational adaptations, there are two key factors in finding resilient pathways when challenged with the uncertainty surrounding climate change and other pressures. The first is the maintenance of flexibility and the avoidance of path dependence, to ensure ongoing adaptive capacity. Secondly, it needs to be recognised that resilience occurs at different scales. In some cases, adaptation measures that increase resilience at farm level, such as importing feed, may reduce resilience at a broader scale, which may in turn come under pressure from climate change.

The combined methodological approach meant that it was possible to reach beyond the limitations of each and form a more holistic picture of potential adaptation strategies. Some strategies lent themselves easily to testing in a model, while others were well beyond its scope.  Conversely, the modelling work enabled a more objective and quantified assessment of farmer perceptions about the resilience of their systems. 

Every adaptation decision involves a set of trade-offs. In conclusion, some of the trade-offs identified as part of this study are summarised for the range of adaptation strategies as originally identified from the literature. Conscious articulation of these trade-offs, in terms of the factors important for ongoing system resilience, is the first step in better informed choices that may lead to more sustainable development of future farming systems.

text: Adaptation of New Zealand dairy farms to climate change: An integrated, farm-level analysis The dairy sector is a cornerstone of the New Zealand economy and as such, it is important to understand the ways in which it is likely to be affected by climate change, whether it will need to adapt, and if so, how this can best be achieved. The overall goal of this research was to analyse potential strategies for New Zealand dairy farms to adapt to projected climate change. For this purpose, an integrated biophysical and socio-economic research framework was developed. Drawing on recognised frameworks for the analysis of climate change adaptation, together with systems analysis methodologies, the framework sets out an integrated process for analysing potential adaptation strategies at farm level.

Six case study farms were selected for the analysis, representing major dairying regions in New Zealand and covering a range of climatic zones and management approaches. The farmers selected were experienced and respected operators, in order to draw on their knowledge of farming systems resilience. Qualitative social research provided insights into the way the farmers saw their farming systems and how climate change issues were placed in the context of other challenges facing the farmers. It also provided a farmer perspective on some of the driving forces that influence the current trajectories of New Zealand dairy systems, in particular their concerns around the effects of environmental regulation and changes in farm structure, which may affect the future adaptive capacity of their farming systems. 

The next step in the analysis was to model the farms in the DairyNZ Whole Farm Model (WFM) under dynamically downscaled climate change scenarios provided by the National Institute of Water and Atmospheric Research (NIWA). This showed significant potential for some adaptations to mitigate the projected impacts of climate change. For example, making and feeding out more silage, and changing the pasture species modelled, showed benefits for nearly all farming systems. However, there were limitations in the capacity of the model to accurately represent the on-farm challenges of implementing such adaptations. Feedback from the farmers highlighted the limitations, as well as the potential value of such modelling work, emphasising the importance of assessing such research in context.

A second round of modelling work was carried out based on the suggestions of individual farmers for their own farms. The suggestions made by farmers were predominantly incremental, rather than transformational adaptations, reflecting the farmer’s positive assessment of the current level of resilience in their farming systems, but also reflecting their operational and personal constraints.  Modelling under present conditions and future climate showed that many of the adaptations did mitigate the impacts of climate change. However, there was still a largely negative impact compared to the same adaptations carried out under the baseline (current) climate. This implies that ongoing work, innovation and technological adjustments will be required to optimise these farming systems under future climate conditions.

For both incremental and transformational adaptations, there are two key factors in finding resilient pathways when challenged with the uncertainty surrounding climate change and other pressures. The first is the maintenance of flexibility and the avoidance of path dependence, to ensure ongoing adaptive capacity. Secondly, it needs to be recognised that resilience occurs at different scales. In some cases, adaptation measures that increase resilience at farm level, such as importing feed, may reduce resilience at a broader scale, which may in turn come under pressure from climate change.

The combined methodological approach meant that it was possible to reach beyond the limitations of each and form a more holistic picture of potential adaptation strategies. Some strategies lent themselves easily to testing in a model, while others were well beyond its scope.  Conversely, the modelling work enabled a more objective and quantified assessment of farmer perceptions about the resilience of their systems. 

Every adaptation decision involves a set of trade-offs. In conclusion, some of the trade-offs identified as part of this study are summarised for the range of adaptation strategies as originally identified from the literature. Conscious articulation of these trade-offs, in terms of the factors important for ongoing system resilience, is the first step in better informed choices that may lead to more sustainable development of future farming systems.

year: 2015

title: Evaluation of land in Wairoa District for potential horticultural development

authors: Rau, Johnathon Taukiri

subjects: land suitability

abstract: The Wairoa District, on the East Coast of the North Island of New Zealand has less horticultural development than areas to the north and south. The objective of this study was to provide information to help inform landowners who may wish to invest in horticulture which could improve the economic situation of the district.
Field work involving local scale climate mapping and soil characterisation of areas with potential for horticulture in Wairoa District was completed in 2017. Constructed climate and topographical maps with existing soil maps were evaluated against known crop growth requirements to produce crop potential maps identifying areas with potential for crop production. Horticultural crops included in this study include kiwifruit, apples, cherries. Alternative crops include hemp and poppies.
Between mid-April – 31 October 2017, 45 portable iButton temperature loggers were deployed throughout Land Use Capability classes 1-3 in the Wairoa District and were set to record hourly temperature. When regressed against nearby climate stations, long term (18 -26 years) temperature datasets were derived from the short term iButton datasets. MODIS satellite images were also analysed to help identify areas prone to frost. From the long-term datasets local scale chill hour, growing degree days and October frost risk maps were constructed for the Wairoa District. For the central area from Wairoa to Frasertown, chill hours were estimated to range between 600 – 900, growing degree days 1300 – 1400 and October frost risk less than 25%.
From four representative soil types, horizon samples were taken to determine the soils physical properties including each horizons Total Available Water Holding Capacity (TAWHC). Horizon TAWHC for each soil type were summed to give TAWHC to 1 meter which along with 21 years of estimated daily rainfall and potential evapotranspiration were used in a soil water balance model to estimate seasonal crop irrigation requirements. Irrigation estimates for kiwifruit compared well against published values ranging between mean 204 – 247 mm.
The crop potential maps with seasonal crop irrigation estimates can enhance a land owner’s ability to make informed decisions resulting in economic benefit to whanau, community and the Wairoa District.

text: Evaluation of land in Wairoa District for potential horticultural development The Wairoa District, on the East Coast of the North Island of New Zealand has less horticultural development than areas to the north and south. The objective of this study was to provide information to help inform landowners who may wish to invest in horticulture which could improve the economic situation of the district.
Field work involving local scale climate mapping and soil characterisation of areas with potential for horticulture in Wairoa District was completed in 2017. Constructed climate and topographical maps with existing soil maps were evaluated against known crop growth requirements to produce crop potential maps identifying areas with potential for crop production. Horticultural crops included in this study include kiwifruit, apples, cherries. Alternative crops include hemp and poppies.
Between mid-April – 31 October 2017, 45 portable iButton temperature loggers were deployed throughout Land Use Capability classes 1-3 in the Wairoa District and were set to record hourly temperature. When regressed against nearby climate stations, long term (18 -26 years) temperature datasets were derived from the short term iButton datasets. MODIS satellite images were also analysed to help identify areas prone to frost. From the long-term datasets local scale chill hour, growing degree days and October frost risk maps were constructed for the Wairoa District. For the central area from Wairoa to Frasertown, chill hours were estimated to range between 600 – 900, growing degree days 1300 – 1400 and October frost risk less than 25%.
From four representative soil types, horizon samples were taken to determine the soils physical properties including each horizons Total Available Water Holding Capacity (TAWHC). Horizon TAWHC for each soil type were summed to give TAWHC to 1 meter which along with 21 years of estimated daily rainfall and potential evapotranspiration were used in a soil water balance model to estimate seasonal crop irrigation requirements. Irrigation estimates for kiwifruit compared well against published values ranging between mean 204 – 247 mm.
The crop potential maps with seasonal crop irrigation estimates can enhance a land owner’s ability to make informed decisions resulting in economic benefit to whanau, community and the Wairoa District.

year: 2018