title: Oceanographic and morphodynamic monitoring of a multi-purpose reef at Mount Maunganui, New Zealand

authors: Weppe, Simon Bastien

subjects: multi-purpose reef

abstract: The innovative concept of an offshore submerged multi-purpose reef combining a
coastal protection function with recreational benefits including improved surfing,
diving, or fishing conditions provides an appealing solution for the management
of beaches. However, since the technology is relatively recent, there is still a lack
of empirical knowledge about its performance in the field. The present research
monitored the effect of the prototype  research  reef constructed at Mount
Maunganui in New Zealand on the local beach morphodynamics and
oceanographic conditions, being primarily concerned with implications on the
coastal protection function of the technology.
The beach morphodynamic response to the reef was investigated from a set of
already available high resolution bathymetric surveys imaging the foreshore and
surfzone morphology prior to, and throughout reef construction, and a new postconstruction
survey collected as a part of this research. The reef implementation
was found to disturb the pre-existing beach state functioning including the
onshore/offshore migration of the underlying long shore bar, rather than cause a
persistent salient response. A possible additional beach width of ~ 20 m,
extending ~ 150 m alongshore was identified in the lee of the reef from shoreline
analysis, but the pattern was transient throughout the monitoring period since it
was superimposed on comparatively large pre-existing fluctuations. In addition,
the reef structure provided a control point on the offshore morphology able to trap
sediment updrift and erode sediment downdrift.
Both field measurements and numerical modelling of waves and currents were
used to monitor the effect of the reef on the oceanographic conditions. Wave
propagation over the reef without breaking (H less than 0.5 m) resulted in transmitted
heights larger than incident by up to a factor of 2. When the reef triggered
breaking, transmitted heights were reduced by up to ~40 %. A concurrent process
was the shift of the wave energy spectra towards higher frequencies landward of
the reef that resulted in reduced transmitted wave periods. Wave modelling
showed that the wave shadowing was associated with significant wave rotation
around the reef that induced two zones of divergent wave angles near the
shoreline in the lee of the reef. The hydrodynamic response to the wave energy
dissipation was the development of stronger onshore directed currents landward of
the reef. Hydrodynamic modelling indicated that the reef-induced flow forced a
cellular circulation in the lee side under shore normal waves, and an onshore
deviation of the ambient (unidirectional) long-shore currents under oblique waves.
The research provided a rare empirical test to the theoretical design concepts, and
potential supplements or refinements. To obtain the required beach protection, the
reef impact on the beach morphodynamic coupling including wave
transformation, nearshore hydrodynamics, and small/large scale beach state
response needs to be carefully assessed.

text: Oceanographic and morphodynamic monitoring of a multi-purpose reef at Mount Maunganui, New Zealand The innovative concept of an offshore submerged multi-purpose reef combining a
coastal protection function with recreational benefits including improved surfing,
diving, or fishing conditions provides an appealing solution for the management
of beaches. However, since the technology is relatively recent, there is still a lack
of empirical knowledge about its performance in the field. The present research
monitored the effect of the prototype  research  reef constructed at Mount
Maunganui in New Zealand on the local beach morphodynamics and
oceanographic conditions, being primarily concerned with implications on the
coastal protection function of the technology.
The beach morphodynamic response to the reef was investigated from a set of
already available high resolution bathymetric surveys imaging the foreshore and
surfzone morphology prior to, and throughout reef construction, and a new postconstruction
survey collected as a part of this research. The reef implementation
was found to disturb the pre-existing beach state functioning including the
onshore/offshore migration of the underlying long shore bar, rather than cause a
persistent salient response. A possible additional beach width of ~ 20 m,
extending ~ 150 m alongshore was identified in the lee of the reef from shoreline
analysis, but the pattern was transient throughout the monitoring period since it
was superimposed on comparatively large pre-existing fluctuations. In addition,
the reef structure provided a control point on the offshore morphology able to trap
sediment updrift and erode sediment downdrift.
Both field measurements and numerical modelling of waves and currents were
used to monitor the effect of the reef on the oceanographic conditions. Wave
propagation over the reef without breaking (H less than 0.5 m) resulted in transmitted
heights larger than incident by up to a factor of 2. When the reef triggered
breaking, transmitted heights were reduced by up to ~40 %. A concurrent process
was the shift of the wave energy spectra towards higher frequencies landward of
the reef that resulted in reduced transmitted wave periods. Wave modelling
showed that the wave shadowing was associated with significant wave rotation
around the reef that induced two zones of divergent wave angles near the
shoreline in the lee of the reef. The hydrodynamic response to the wave energy
dissipation was the development of stronger onshore directed currents landward of
the reef. Hydrodynamic modelling indicated that the reef-induced flow forced a
cellular circulation in the lee side under shore normal waves, and an onshore
deviation of the ambient (unidirectional) long-shore currents under oblique waves.
The research provided a rare empirical test to the theoretical design concepts, and
potential supplements or refinements. To obtain the required beach protection, the
reef impact on the beach morphodynamic coupling including wave
transformation, nearshore hydrodynamics, and small/large scale beach state
response needs to be carefully assessed.

year: 2010

title: αₙ-Designs

authors: Ruggiero, Katya

abstract: This thesis defines a broad class of resolvable incomplete block designs for multifactor experiments, called αₙ-designs. A general methodology for their construction is described and is shown to be a natural extension of the method used by Patterson and Williams (1976) in their construction of α-designs. In fact, the class of α-designs are a special case of αₙ-designs with n = 1. 

The family of αₙ-designs was primarily developed for their use in factorial experiments. While they are particularly suitable for this purpose, for some combinations of design parameters they also provide more efficient designs than the best available α-designs.

Algorithms for the generation of efficient designs require computationally expensive eigenvalue calculations. Therefore, considerable attention is devoted to the study of the structural properties of αₙ-designs and how these can be used to develop computationally fast algorithms. In this endeavour it is shown that the treatment concurrence and information matrices have an important property known as BⁿC-structure. This is used to derive a closed form mathematical expression for the average efficiency factor of any generalized interaction. It is further shown that this expression can be written recursively. These results, combined with the fact than an αₙ-design is completely specified by a small generating array, mean that computer search algorithms can be developed to quickly find highly efficient designs.

A desirable feature in a factorial design is the property of orthogonal factorial structure. The family of αₙ-designs do not, in general, admit this property. However, another class of n-dimensional cyclic designs, known as n-cyclic designs, suitable for non-resolvable designs for factorial experiments are also considered in this thesis. They possess orthogonal factorial structure and include a sizeable subset of designs which are resolvable. These resolvable n-cyclic designs are shown to be αₙ-designs.

The discovery and subsequent development of the family of αₙ-designs has stimulated a new set of interesting questions in relation to factorial experiments. These are discussed at the end of the thesis.

text: αₙ-Designs This thesis defines a broad class of resolvable incomplete block designs for multifactor experiments, called αₙ-designs. A general methodology for their construction is described and is shown to be a natural extension of the method used by Patterson and Williams (1976) in their construction of α-designs. In fact, the class of α-designs are a special case of αₙ-designs with n = 1. 

The family of αₙ-designs was primarily developed for their use in factorial experiments. While they are particularly suitable for this purpose, for some combinations of design parameters they also provide more efficient designs than the best available α-designs.

Algorithms for the generation of efficient designs require computationally expensive eigenvalue calculations. Therefore, considerable attention is devoted to the study of the structural properties of αₙ-designs and how these can be used to develop computationally fast algorithms. In this endeavour it is shown that the treatment concurrence and information matrices have an important property known as BⁿC-structure. This is used to derive a closed form mathematical expression for the average efficiency factor of any generalized interaction. It is further shown that this expression can be written recursively. These results, combined with the fact than an αₙ-design is completely specified by a small generating array, mean that computer search algorithms can be developed to quickly find highly efficient designs.

A desirable feature in a factorial design is the property of orthogonal factorial structure. The family of αₙ-designs do not, in general, admit this property. However, another class of n-dimensional cyclic designs, known as n-cyclic designs, suitable for non-resolvable designs for factorial experiments are also considered in this thesis. They possess orthogonal factorial structure and include a sizeable subset of designs which are resolvable. These resolvable n-cyclic designs are shown to be αₙ-designs.

The discovery and subsequent development of the family of αₙ-designs has stimulated a new set of interesting questions in relation to factorial experiments. These are discussed at the end of the thesis.

year: 2000

title: An evaluation of the Raukawa Health Services Kaumatua Mirimiri Programme

authors: Gregg, Lisa

subjects: Maori

abstract: The Kaumatua Mirimiri Programme was funded as a Service to Improve Access project under a contract which ran from 1st September 2004 to 30th June 2005. Its aim was to provide a “culturally based treatment and recovery programme to restore the health and independence” of people aged 40 years and over (Pinnacle Group Ltd, 2004a, p.1). However, as the service specification in the contract made clear, the programme was not designed be exclusive: it has attracted younger as well as older people, non-Māori as well as Māori, and people seeking help for a wide range of ailments and pain.

text: An evaluation of the Raukawa Health Services Kaumatua Mirimiri Programme The Kaumatua Mirimiri Programme was funded as a Service to Improve Access project under a contract which ran from 1st September 2004 to 30th June 2005. Its aim was to provide a “culturally based treatment and recovery programme to restore the health and independence” of people aged 40 years and over (Pinnacle Group Ltd, 2004a, p.1). However, as the service specification in the contract made clear, the programme was not designed be exclusive: it has attracted younger as well as older people, non-Māori as well as Māori, and people seeking help for a wide range of ailments and pain.

year: 2006-03