title: Ōhiwa Harbour Delft3D sediment transport modelling to support the National Policy Statement on Freshwater (NPS-FM)

authors: Bryan, Karin R.

abstract: A suspended sediment transport model was set up for Ōhiwa Harbour, which was validated against in situ observations collected between 19/4/21 and 17/5/21. Four sediment grain size fractions were modelled; two cohesive (silt) sediment grain size fractions, and two non-cohesive (sand) sediment grain size fractions. Characteristics of these grain size fractions were selected based on a sensitivity analysis and the match of modelled suspended sediment to the magnitude and temporal patterns recorded at the observation stations. Suspended non-cohesive grain size fractions reflect local current strengths at the sites measured, whereas cohesive grain size fractions are advected longer distances by the ebbing or flooding currents.

Sediment loading was input at the freshwater discharge points using loading scenarios provided by the Bay of Plenty Regional Council. Sediment loading was converted to a concentration and discharge, and input into the model as a cohesive sediment grain size fraction. Model scenarios were run for 1 year in blocks of 3 months, using the environmental conditions (discharge, wind, tides) from 2014 as a base-case scenario. Loading scenarios consisted of contemporary, natural, RCP45 and RCP85 conditions. A 7-day model “warm up” period prior to each of the 3-month blocks was discarded.

text: Ōhiwa Harbour Delft3D sediment transport modelling to support the National Policy Statement on Freshwater (NPS-FM) A suspended sediment transport model was set up for Ōhiwa Harbour, which was validated against in situ observations collected between 19/4/21 and 17/5/21. Four sediment grain size fractions were modelled; two cohesive (silt) sediment grain size fractions, and two non-cohesive (sand) sediment grain size fractions. Characteristics of these grain size fractions were selected based on a sensitivity analysis and the match of modelled suspended sediment to the magnitude and temporal patterns recorded at the observation stations. Suspended non-cohesive grain size fractions reflect local current strengths at the sites measured, whereas cohesive grain size fractions are advected longer distances by the ebbing or flooding currents.

Sediment loading was input at the freshwater discharge points using loading scenarios provided by the Bay of Plenty Regional Council. Sediment loading was converted to a concentration and discharge, and input into the model as a cohesive sediment grain size fraction. Model scenarios were run for 1 year in blocks of 3 months, using the environmental conditions (discharge, wind, tides) from 2014 as a base-case scenario. Loading scenarios consisted of contemporary, natural, RCP45 and RCP85 conditions. A 7-day model “warm up” period prior to each of the 3-month blocks was discarded.

year: 2023

title: Effective supply chain research via the quick scan audit methodology

authors: Childerhouse, Paul

subjects: auditing

abstract: Purpose – This paper aims to provide an answer to the important question of how can accurate assessment of supply chain practice and performance be conducted? By conducting audits across a sample of value streams it is thereby possible to identify the components of “good practice” via evidence-based procedures.

Design/methodology/approach – Quick scan audit methodology (QSAM) is a site-based, team-oriented action research-led investigative technique for establishing meaningful “snapshots” of value stream behaviour. The participants cover both academic researchers and host organisation staff.

Findings – QSAM is found to output repeatable results enabling the transfer of technique between companies, between businesses, between market sectors, and between countries.

Research limitations/implications – Care must be taken when training new auditors and QSAM teams to ensure the required degree of consistency. There is no substitute for operating a “watch one, share one, do one” regimen.

Practical implications – The research purpose is to establish the performance vectors to enable effective value stream health comparisons to be made. Additionally “quick hits” (not “quick fixes”) may well be identified specific to an individual host organisation.

Originality/value – QSAM has already made an important contribution in enabling the gap between case-based and survey-based logistics research to be properly bridged.

text: Effective supply chain research via the quick scan audit methodology Purpose – This paper aims to provide an answer to the important question of how can accurate assessment of supply chain practice and performance be conducted? By conducting audits across a sample of value streams it is thereby possible to identify the components of “good practice” via evidence-based procedures.

Design/methodology/approach – Quick scan audit methodology (QSAM) is a site-based, team-oriented action research-led investigative technique for establishing meaningful “snapshots” of value stream behaviour. The participants cover both academic researchers and host organisation staff.

Findings – QSAM is found to output repeatable results enabling the transfer of technique between companies, between businesses, between market sectors, and between countries.

Research limitations/implications – Care must be taken when training new auditors and QSAM teams to ensure the required degree of consistency. There is no substitute for operating a “watch one, share one, do one” regimen.

Practical implications – The research purpose is to establish the performance vectors to enable effective value stream health comparisons to be made. Additionally “quick hits” (not “quick fixes”) may well be identified specific to an individual host organisation.

Originality/value – QSAM has already made an important contribution in enabling the gap between case-based and survey-based logistics research to be properly bridged.

year: 2010

title: Tephras and New Zealand archaeology

authors: Lowe, David J.

subjects: tephrochronology

abstract: Establishing an accurate date for earliest Polynesian settlement in New Zealand is essential for understanding patterns of settlement and associated environmental impacts, and the processes and rates of cultural change in Eastern Polynesia. Tephra deposits from five volcanic centres, together with exotic sea-rafted pumice, provide isochronous constraints on the timing of earliest settlement and human impacts in northern New Zealand. A local basaltic tephra from Rangitoto Island (Auckland) and locally distributed andesitic tephras from Egmont volcano directly date human occupation to c. AD 1400–1450. Distal andesitic tephras (Tufa Trig Formation) from Mt Ruapehu, Tongariro volcanic centre, help constrain the timing of earliest anthropogenic deforestation signals in Hawke's Bay. Sea-rafted Loisels Pumice(s), although of uncertain stratigraphic reliability in places, overlies cultural remains that can be no younger than c. AD 1350 along the east coast, North Island. The regionally extensive rhyolitic Kaharoa Tephra, which erupted from Okataina volcano between c. AD  1300–1390, is the critical “settlement layer” datum for dating prehistory in the North Island: no human artefacts are recorded beneath it and the earliest inferred environmental impacts by humans are dated to c. AD  1280, just prior to its deposition. This maximum date matches the earliest radiocarbon dates derived for both settlement and human impacts from archaeological and natural sites (c. AD 1250), and implies that the onset of deforestation was essentially contemporaneous with initial settlement.
The widespread rhyolitic Taupo Tephra, which erupted from Taupo volcano c. AD 200, provides an isochronous benchmark well before earliest settlement. The tephra may coincide approximately with a putative earlier transient contact in New Zealand based on Pacific rat-bone (Rattus exulans) dates. More precise calendrical dates on the tephras—via dendrochronology or ice-core records or other dating methods—would help refine assessment of the timing of earliest settlement, while extending the distributional range of critical tephra layers, through application of crypto-tephra analysis, could lead to a greater understanding of settlement patterns.

text: Tephras and New Zealand archaeology Establishing an accurate date for earliest Polynesian settlement in New Zealand is essential for understanding patterns of settlement and associated environmental impacts, and the processes and rates of cultural change in Eastern Polynesia. Tephra deposits from five volcanic centres, together with exotic sea-rafted pumice, provide isochronous constraints on the timing of earliest settlement and human impacts in northern New Zealand. A local basaltic tephra from Rangitoto Island (Auckland) and locally distributed andesitic tephras from Egmont volcano directly date human occupation to c. AD 1400–1450. Distal andesitic tephras (Tufa Trig Formation) from Mt Ruapehu, Tongariro volcanic centre, help constrain the timing of earliest anthropogenic deforestation signals in Hawke's Bay. Sea-rafted Loisels Pumice(s), although of uncertain stratigraphic reliability in places, overlies cultural remains that can be no younger than c. AD 1350 along the east coast, North Island. The regionally extensive rhyolitic Kaharoa Tephra, which erupted from Okataina volcano between c. AD  1300–1390, is the critical “settlement layer” datum for dating prehistory in the North Island: no human artefacts are recorded beneath it and the earliest inferred environmental impacts by humans are dated to c. AD  1280, just prior to its deposition. This maximum date matches the earliest radiocarbon dates derived for both settlement and human impacts from archaeological and natural sites (c. AD 1250), and implies that the onset of deforestation was essentially contemporaneous with initial settlement.
The widespread rhyolitic Taupo Tephra, which erupted from Taupo volcano c. AD 200, provides an isochronous benchmark well before earliest settlement. The tephra may coincide approximately with a putative earlier transient contact in New Zealand based on Pacific rat-bone (Rattus exulans) dates. More precise calendrical dates on the tephras—via dendrochronology or ice-core records or other dating methods—would help refine assessment of the timing of earliest settlement, while extending the distributional range of critical tephra layers, through application of crypto-tephra analysis, could lead to a greater understanding of settlement patterns.

year: 2000