title: Modelling the hydrodynamics within the mangrove tidal flats in the Firth of Thames

authors: Haughey, Rebekah Rose

subjects: mangroves

abstract: Understanding how mangroves control shoreline stability, through altering hydrodynamic and sedimentation patterns, is important to predicting how resilient our coastline is to climate change. Recent work has shown that some mangrove ecosystems may modify the morphology, and allow the seabed to evolve upward with rising sea level, and thus alleviating the pressure on coastal adaptation.
This study is focussed on improving the understanding of the hydrodynamics within the mangrove habitat in the Firth of Thames, New Zealand. The mangrove habitat within the Firth of Thames is a shallow, muddy and rapidly prograding environment. The main aim of this study was to determine whether or not, the mangroves influence the dynamics of the tidal wave propagation, which in turn can have implications for the sedimentation patterns and shoreline stability within the Firth of Thames.
A hydrodynamic model for the Firth of Thames was developed using Delft3D. A coarse resolution grid was created to simulate the offshore tidal wave propagation and used to force a nested, fine resolution grid within the mangrove intertidal flats. A field deployment was completed during May 2016, where in the offshore region water levels, current velocities and suspended sediment measurements were taken, and within the mangrove forest, water levels, bed elevations and vegetation characteristics were measured. Field measurements were used to calibrate both the overall and nested models.
Comparisons between model outputs, with and without vegetation included in the model, indicate that the presence of mangroves does influence the tidal wave dynamics across the intertidal flats. Two of the main effects of vegetation were reduced current velocity and tidal amplitude. Regardless of whether mangroves were present, the model showed flood dominance across the upper intertidal flat and ebb dominance at the seaward edge of the intertidal flat. However, with vegetation included this pattern of tidal asymmetry was enhanced, due to the nonlinear effect of friction.
A series of numerical experiments were also performed to understand the control of sea bed roughness and vegetation characteristics (vegetation roughness, pneumatophore height, plus pneumatophore and tree density) on the size, spatial changes and timing of tidal currents. Pneumatophore density had the largest influence on model outputs, with increasing pneumatophore density causing a reduction in currents and a delay in the drainage of the ebb tide.
Based on the hydrodynamic model outputs and measurements of offshore suspended sediment concentrations, rough calculations were completed to estimate the net flux of sediment into the forest over time. Estimated sediment fluxes were surprisingly similar to the estimated volume deposited sediment between the 2005 and 2016 elevation surveys.
Physical processes, such as tidal asymmetry, are likely to have caused the initial accretion and tidal flat development, making it suitable for mangrove growth. However, now that there is a vast area of mangroves, they are altering the hydrodynamics and therefore are also contributing to the accretion and overall stability of the system.

text: Modelling the hydrodynamics within the mangrove tidal flats in the Firth of Thames Understanding how mangroves control shoreline stability, through altering hydrodynamic and sedimentation patterns, is important to predicting how resilient our coastline is to climate change. Recent work has shown that some mangrove ecosystems may modify the morphology, and allow the seabed to evolve upward with rising sea level, and thus alleviating the pressure on coastal adaptation.
This study is focussed on improving the understanding of the hydrodynamics within the mangrove habitat in the Firth of Thames, New Zealand. The mangrove habitat within the Firth of Thames is a shallow, muddy and rapidly prograding environment. The main aim of this study was to determine whether or not, the mangroves influence the dynamics of the tidal wave propagation, which in turn can have implications for the sedimentation patterns and shoreline stability within the Firth of Thames.
A hydrodynamic model for the Firth of Thames was developed using Delft3D. A coarse resolution grid was created to simulate the offshore tidal wave propagation and used to force a nested, fine resolution grid within the mangrove intertidal flats. A field deployment was completed during May 2016, where in the offshore region water levels, current velocities and suspended sediment measurements were taken, and within the mangrove forest, water levels, bed elevations and vegetation characteristics were measured. Field measurements were used to calibrate both the overall and nested models.
Comparisons between model outputs, with and without vegetation included in the model, indicate that the presence of mangroves does influence the tidal wave dynamics across the intertidal flats. Two of the main effects of vegetation were reduced current velocity and tidal amplitude. Regardless of whether mangroves were present, the model showed flood dominance across the upper intertidal flat and ebb dominance at the seaward edge of the intertidal flat. However, with vegetation included this pattern of tidal asymmetry was enhanced, due to the nonlinear effect of friction.
A series of numerical experiments were also performed to understand the control of sea bed roughness and vegetation characteristics (vegetation roughness, pneumatophore height, plus pneumatophore and tree density) on the size, spatial changes and timing of tidal currents. Pneumatophore density had the largest influence on model outputs, with increasing pneumatophore density causing a reduction in currents and a delay in the drainage of the ebb tide.
Based on the hydrodynamic model outputs and measurements of offshore suspended sediment concentrations, rough calculations were completed to estimate the net flux of sediment into the forest over time. Estimated sediment fluxes were surprisingly similar to the estimated volume deposited sediment between the 2005 and 2016 elevation surveys.
Physical processes, such as tidal asymmetry, are likely to have caused the initial accretion and tidal flat development, making it suitable for mangrove growth. However, now that there is a vast area of mangroves, they are altering the hydrodynamics and therefore are also contributing to the accretion and overall stability of the system.

year: 2017

title: Contexts, refinement and determinism

authors: Reeves, Steve

subjects: computer science

abstract: In this paper we have been influenced by those who take an “engineering view” of the problem of designing systems, i.e. a view that is motivated by what someone designing a real system will be concerned with, and what questions will arise as they work on their design. Specifically, we have borrowed from the testing work of Hennessy, de Nicola and van Glabbeek, e.g. [13, 5, 21, 40, 39].
Here we concentrate on one fundamental part of the engineering view and where consideration of it leads. The aspects we are concerned with are computational entities in contexts, observed by users. This leads to formalising design steps that are often left informal, and that in turn gives insights into non-determinism and ultimately leads to being able to use refinement in situations where existing techniques fail.

text: Contexts, refinement and determinism In this paper we have been influenced by those who take an “engineering view” of the problem of designing systems, i.e. a view that is motivated by what someone designing a real system will be concerned with, and what questions will arise as they work on their design. Specifically, we have borrowed from the testing work of Hennessy, de Nicola and van Glabbeek, e.g. [13, 5, 21, 40, 39].
Here we concentrate on one fundamental part of the engineering view and where consideration of it leads. The aspects we are concerned with are computational entities in contexts, observed by users. This leads to formalising design steps that are often left informal, and that in turn gives insights into non-determinism and ultimately leads to being able to use refinement in situations where existing techniques fail.

year: 2010

title: Adult literacy and numeracy in Aotearoa New Zealand: How does current research and organisational reporting align with the Living Standards Framework?

authors: Hockings, Nicki Samantha

subjects: Literacy

abstract: Literacy and numeracy are foundational skills that are important in everyday life. Dominant western perspectives of literacy and numeracy focus on skills attainment for economic benefit and international comparison; this is a neoliberal approach that influences policy development in developed countries worldwide. However, there is growing recognition that high rates of economic productivity do not provide an accurate indicator of success for either individuals or nations. In support of this position, this thesis favours a sociomaterial approach to literacy and numeracy, prioritising people’s abilities to communicate and navigate their world effectively, while engaging in meaningful social practices that allow them to participate in family and community. This master’s research sought to understand the connections between adult literacy and numeracy learners, wellbeing outcomes, and the Living Standards Framework. The New Zealand Treasury’s Living Standards Framework (LSF) was developed to provide a view of intergenerational wellbeing in Aotearoa New Zealand; it underpins the government’s wellbeing focus for budgetary and policy decisions. A community psychology and Kaupapa Māori lens was applied to critically evaluate whether the LSF aligns with community psychology values and principles in Aotearoa New Zealand, and, most importantly, whether it reflects Māori cultural views and values. The value of the LSF in the adult literacy and numeracy education context was also examined, with particular emphasis on similarities between the LSF, literacy and numeracy learning opportunities, and learner outcomes; and whether the use of the LSF in adult education programmes and policies would complement the existing approach. The study involved a document analysis of six key LSF documents and six literacy and numeracy research reports. Each document was analysed using deductive and inductive means, which enabled the identification of themes and subthemes that reflected underlying values, approaches, and outcomes. To augment the document analysis, six interviews were held with report authors and key personnel from relevant organisations; these added value to the research by exploring the values that underpin literacy and numeracy research and reporting in Aotearoa New Zealand. The findings conclude that the 2018 LSF was based on sound international principles, but lacked a genuine perspective of wellbeing in Aotearoa New Zealand. A recently-launched 2021 LSF has undergone an ‘evolution’ and is presented in a much more holistic style, acknowledging its previous shortcomings in addressing concepts of wellbeing in Aotearoa New Zealand. Two accompanying Māori-led documents: An Indigenous Approach to the Living Standards Framework, and He Ara Waiora, both offer a holistic, te ao Māori perspective of wellbeing. The document analysis highlighted a sociomaterial, values based approach to adult literacy and numeracy education that prioritised holistic wellbeing outcomes for learners and their whānau. These findings were supported by the interview data. The final discussion and conclusion posited that the 2021 Living Standards Framework provides a welcome update and potential for genuine, Aotearoa-specific wellbeing considerations in policy-making and governance; however, it remains to be seen whether this will translate into changes in policy-making and programme delivery for the literacy and numeracy sector.

text: Adult literacy and numeracy in Aotearoa New Zealand: How does current research and organisational reporting align with the Living Standards Framework? Literacy and numeracy are foundational skills that are important in everyday life. Dominant western perspectives of literacy and numeracy focus on skills attainment for economic benefit and international comparison; this is a neoliberal approach that influences policy development in developed countries worldwide. However, there is growing recognition that high rates of economic productivity do not provide an accurate indicator of success for either individuals or nations. In support of this position, this thesis favours a sociomaterial approach to literacy and numeracy, prioritising people’s abilities to communicate and navigate their world effectively, while engaging in meaningful social practices that allow them to participate in family and community. This master’s research sought to understand the connections between adult literacy and numeracy learners, wellbeing outcomes, and the Living Standards Framework. The New Zealand Treasury’s Living Standards Framework (LSF) was developed to provide a view of intergenerational wellbeing in Aotearoa New Zealand; it underpins the government’s wellbeing focus for budgetary and policy decisions. A community psychology and Kaupapa Māori lens was applied to critically evaluate whether the LSF aligns with community psychology values and principles in Aotearoa New Zealand, and, most importantly, whether it reflects Māori cultural views and values. The value of the LSF in the adult literacy and numeracy education context was also examined, with particular emphasis on similarities between the LSF, literacy and numeracy learning opportunities, and learner outcomes; and whether the use of the LSF in adult education programmes and policies would complement the existing approach. The study involved a document analysis of six key LSF documents and six literacy and numeracy research reports. Each document was analysed using deductive and inductive means, which enabled the identification of themes and subthemes that reflected underlying values, approaches, and outcomes. To augment the document analysis, six interviews were held with report authors and key personnel from relevant organisations; these added value to the research by exploring the values that underpin literacy and numeracy research and reporting in Aotearoa New Zealand. The findings conclude that the 2018 LSF was based on sound international principles, but lacked a genuine perspective of wellbeing in Aotearoa New Zealand. A recently-launched 2021 LSF has undergone an ‘evolution’ and is presented in a much more holistic style, acknowledging its previous shortcomings in addressing concepts of wellbeing in Aotearoa New Zealand. Two accompanying Māori-led documents: An Indigenous Approach to the Living Standards Framework, and He Ara Waiora, both offer a holistic, te ao Māori perspective of wellbeing. The document analysis highlighted a sociomaterial, values based approach to adult literacy and numeracy education that prioritised holistic wellbeing outcomes for learners and their whānau. These findings were supported by the interview data. The final discussion and conclusion posited that the 2021 Living Standards Framework provides a welcome update and potential for genuine, Aotearoa-specific wellbeing considerations in policy-making and governance; however, it remains to be seen whether this will translate into changes in policy-making and programme delivery for the literacy and numeracy sector.

year: 2022