title: Investigation of a 'Field Factory' to harvest and grade tree stock in a forestry nursery

authors: McGuinness, Benjamin John

abstract: Primary industries are facing an ever increasing labour problem. Major concerns with labour include lack of staff training, high costs, poor efficiency, non-optimal quality control and health and safety issues. While automation is commonplace in factory environments, such technologies have not yet migrated to an outdoor, agricultural environment. Forestry nurseries are no exception, where the most problematic and labour intensive task is lifting and grading tree stock.

Mechanical lifting of tree stock is already performed commercially; however, these machines are incapable of performing the additional steps required by this research, particularly root trimming, coupled with a machine vision system that can replicate the human decision making process for selecting ’good’ and ’bad’ tree stock. In particular, there are strict criteria for root structure which must be assessed. Currently, human graders are proving to be poor assessors of this, to such an extent that tree stock is graded up to three times before being shipped to the customer. Additionally, there is the need to remove expensive pack houses. This research investigates a field factory capable of processing forestry tree stock in the field, from lifting through to grading and boxing. 

The machine vision component of the field factory was tested in controlled conditions, on a sample of 200 trees. There was good agreement between machine vision measurements and manually measured tree features. There is much ambiguity in the grading process, with three experts only reaching a consensus 75% of the time when grading a sample of trees. The machine vision grading system performed very well, showing less bias than human graders.  The machine agreed with the specification 96% of the time, significantly higher than the experts’ agreements of between 86 and 90%. While classification systems such as fuzzy logic and artificial neural networks seem to be a good match for this research, they did not outperform the ’crisp’ grading system.

A field factory for harvesting and grading forestry tree stock proved to be feasible; however, further development, particularly on mechanical systems, is required to produce a machine reliable enough to be implemented commercially.

text: Investigation of a 'Field Factory' to harvest and grade tree stock in a forestry nursery Primary industries are facing an ever increasing labour problem. Major concerns with labour include lack of staff training, high costs, poor efficiency, non-optimal quality control and health and safety issues. While automation is commonplace in factory environments, such technologies have not yet migrated to an outdoor, agricultural environment. Forestry nurseries are no exception, where the most problematic and labour intensive task is lifting and grading tree stock.

Mechanical lifting of tree stock is already performed commercially; however, these machines are incapable of performing the additional steps required by this research, particularly root trimming, coupled with a machine vision system that can replicate the human decision making process for selecting ’good’ and ’bad’ tree stock. In particular, there are strict criteria for root structure which must be assessed. Currently, human graders are proving to be poor assessors of this, to such an extent that tree stock is graded up to three times before being shipped to the customer. Additionally, there is the need to remove expensive pack houses. This research investigates a field factory capable of processing forestry tree stock in the field, from lifting through to grading and boxing. 

The machine vision component of the field factory was tested in controlled conditions, on a sample of 200 trees. There was good agreement between machine vision measurements and manually measured tree features. There is much ambiguity in the grading process, with three experts only reaching a consensus 75% of the time when grading a sample of trees. The machine vision grading system performed very well, showing less bias than human graders.  The machine agreed with the specification 96% of the time, significantly higher than the experts’ agreements of between 86 and 90%. While classification systems such as fuzzy logic and artificial neural networks seem to be a good match for this research, they did not outperform the ’crisp’ grading system.

A field factory for harvesting and grading forestry tree stock proved to be feasible; however, further development, particularly on mechanical systems, is required to produce a machine reliable enough to be implemented commercially.

year: 2018

title: Coastal erosion and sedimentation of Pukehina Beach and Waihi Estuary

authors: Easton, Hayden Russell

subjects: Pukehina Beach

abstract: The Pukehina coastal sector is subject to severe frontal dune erosion. This has led to concern from local residents who reside in frontal houses. Accordingly, this investigation was initiated to assess the sedimentary and physical processes within the Pukehina coastal sector, with the aim of identifying causes of enhanced frontal dune erosion.
To investigate this problem the following processes were investigated: wave focusing from offshore bathymetric lenses, sediment lost due to the Waihi Estuary acting as a sediment sink, and/or a change in sediment volume or sediment transport processes within the Pukehina coastal sector. Methods to investigate these processes included: collection and analysis of surficial sediment samples from Pukehina Beach and Waihi Estuary, construction of a digital terrain model, side scan sonar surveying, calculation of offshore suspended sediment concentrations, numerical modelling of wave refraction and sediment transport processes, and collection and analysis of wave and estuarine current, depth, and direction data.
Wave data were collected at eastern and western ends of the study location, during two separate deployments during July 2000 and March 2001. Outcomes depict differing incoming wave directions at each site, due to offshore undulations in bathymetry. Wave energy focusing was observed along the Pukehina coastal sector (specifically at benchmarks 30, 29, 27 and 26a) during average wave conditions recorded, and enhanced as wave period and wave height increased (approximately 0.2-2.0 m in each simulation, respectively). Wave focusing is significantly influenced by the ebb tidal delta offshore from Waihi Estuary, leading to larger wave heights present in eroding regions of Pukehina Beach.
Potential sediment transport rates were investigated, utilising collected wave data. Outcomes illustrate a potential sediment transport to the east. A negative littoral drift gradient, was observed between a) Okurei Point and Waihi Estuary inlet, and a positive littoral drift gradient between b) benchmark 29 and 26. This implies a potential accumulation of sediments near Waihi Estuary inlet (some of which, would be lost to infilling of Waihi Estuary). However, a long-term deficit (-12 m3/m per year) of sediment is lost along Pukehina Beach, due to the apparent positive littoral drift gradient. This outcome is identified as a major component of the long-term 'erosion' problem at Pukehina Beach.
Tidal and current gauges were deployed within Waihi Estuary. Data revealed strong evidence that the estuary is acting as a sediment sink. Tidal asymmetry, attenuation of the tidal signal and a dominance of sediment transport into the estuary, depict that Waihi Estuary is an influential component of the erosion occurring at Pukehina Beach. The Waihi Estuary is calculated by geomorphic and hydraulic analysis to be tending towards deposition in the inlet, leading to a general instability of the Waihi Estuary inlet.
Nearshore sediment transport rates within the region are significantly influenced by localised wind patterns within the Pukehina coastal sector. The Pukehina coastal sector was identified as having a net deficit of sediment, approximately 4,500 m³/year or -0.5 m³/m per year. However, due to errors involved in estimate calculations, this value may be larger.
Sediment textural distributions have altered since previous surveys conducted in 1993 by PHIZACKLEA. Particularly, an influx of sediment to the Okurei Point region, reducing the area of exposed bedrock, suggests a change of sediment transport patterns within this region. Texturally, offshore sediments vary from fine sand sized sediments to very coarse sand, while beach sediments are predominantly medium sand sized particles, with a decrease in sediment size towards Okurei Point (fine sand sized particles), indicating a sediment transport direction to the west.
Causes of significant long-term erosion to the Pukehina coastal sector, have been identified as: a) beach-nearshore sediment being lost or 'sucked out' of the coastal sector, due to the combination of a positive littoral drift gradient along Pukehina Beach, and wave energy focusing; and b) infilling of the Waihi Estuary. Other processes, such as aeolian transport etc., do reduce the volume of available sediment to Pukehina Beach, but are not implicated to the long-term 'erosion' problem occurring.
Possible remedial solutions, influenced by data observations, are suggested to reduce current frontal dune erosion. However, further research is recommended to identify what coastal management options are required for the Pukehina Beach shoreline.

text: Coastal erosion and sedimentation of Pukehina Beach and Waihi Estuary The Pukehina coastal sector is subject to severe frontal dune erosion. This has led to concern from local residents who reside in frontal houses. Accordingly, this investigation was initiated to assess the sedimentary and physical processes within the Pukehina coastal sector, with the aim of identifying causes of enhanced frontal dune erosion.
To investigate this problem the following processes were investigated: wave focusing from offshore bathymetric lenses, sediment lost due to the Waihi Estuary acting as a sediment sink, and/or a change in sediment volume or sediment transport processes within the Pukehina coastal sector. Methods to investigate these processes included: collection and analysis of surficial sediment samples from Pukehina Beach and Waihi Estuary, construction of a digital terrain model, side scan sonar surveying, calculation of offshore suspended sediment concentrations, numerical modelling of wave refraction and sediment transport processes, and collection and analysis of wave and estuarine current, depth, and direction data.
Wave data were collected at eastern and western ends of the study location, during two separate deployments during July 2000 and March 2001. Outcomes depict differing incoming wave directions at each site, due to offshore undulations in bathymetry. Wave energy focusing was observed along the Pukehina coastal sector (specifically at benchmarks 30, 29, 27 and 26a) during average wave conditions recorded, and enhanced as wave period and wave height increased (approximately 0.2-2.0 m in each simulation, respectively). Wave focusing is significantly influenced by the ebb tidal delta offshore from Waihi Estuary, leading to larger wave heights present in eroding regions of Pukehina Beach.
Potential sediment transport rates were investigated, utilising collected wave data. Outcomes illustrate a potential sediment transport to the east. A negative littoral drift gradient, was observed between a) Okurei Point and Waihi Estuary inlet, and a positive littoral drift gradient between b) benchmark 29 and 26. This implies a potential accumulation of sediments near Waihi Estuary inlet (some of which, would be lost to infilling of Waihi Estuary). However, a long-term deficit (-12 m3/m per year) of sediment is lost along Pukehina Beach, due to the apparent positive littoral drift gradient. This outcome is identified as a major component of the long-term 'erosion' problem at Pukehina Beach.
Tidal and current gauges were deployed within Waihi Estuary. Data revealed strong evidence that the estuary is acting as a sediment sink. Tidal asymmetry, attenuation of the tidal signal and a dominance of sediment transport into the estuary, depict that Waihi Estuary is an influential component of the erosion occurring at Pukehina Beach. The Waihi Estuary is calculated by geomorphic and hydraulic analysis to be tending towards deposition in the inlet, leading to a general instability of the Waihi Estuary inlet.
Nearshore sediment transport rates within the region are significantly influenced by localised wind patterns within the Pukehina coastal sector. The Pukehina coastal sector was identified as having a net deficit of sediment, approximately 4,500 m³/year or -0.5 m³/m per year. However, due to errors involved in estimate calculations, this value may be larger.
Sediment textural distributions have altered since previous surveys conducted in 1993 by PHIZACKLEA. Particularly, an influx of sediment to the Okurei Point region, reducing the area of exposed bedrock, suggests a change of sediment transport patterns within this region. Texturally, offshore sediments vary from fine sand sized sediments to very coarse sand, while beach sediments are predominantly medium sand sized particles, with a decrease in sediment size towards Okurei Point (fine sand sized particles), indicating a sediment transport direction to the west.
Causes of significant long-term erosion to the Pukehina coastal sector, have been identified as: a) beach-nearshore sediment being lost or 'sucked out' of the coastal sector, due to the combination of a positive littoral drift gradient along Pukehina Beach, and wave energy focusing; and b) infilling of the Waihi Estuary. Other processes, such as aeolian transport etc., do reduce the volume of available sediment to Pukehina Beach, but are not implicated to the long-term 'erosion' problem occurring.
Possible remedial solutions, influenced by data observations, are suggested to reduce current frontal dune erosion. However, further research is recommended to identify what coastal management options are required for the Pukehina Beach shoreline.

year: 2002

title: Māori men, relationships, and everyday practices: towards broadening domestic violence research

authors: King, Pita

subjects: Māori

abstract: Relationships are central to the health and wellbeing of Māori (indigenous people of New Zealand). Through processes of colonisation, cultural ways of relatedness embedded within Māori social structures experienced disruption and were reshaped over decades of assimilation. Māori knowledge and everyday practices that assisted in protecting Māori from societal problems, such as domestic violence, began to dwindle. In contemporary New Zealand, Māori are over-represented in domestic violence statistics. Utilising an auto-ethnographic approach and case studies, our research focuses on five Māori men’s experiences within intimate relationships and whānau (extended family) life. A significant feature of this research is that it provides insights into the ways Māori men draw on their cultural ways-of-being to enhance intimate relationships and maintain bonds within whānau and community life to forge new ways-of-being. Such insights have the potential to inform preventative measures against domestic violence within Māori communities.

text: Māori men, relationships, and everyday practices: towards broadening domestic violence research Relationships are central to the health and wellbeing of Māori (indigenous people of New Zealand). Through processes of colonisation, cultural ways of relatedness embedded within Māori social structures experienced disruption and were reshaped over decades of assimilation. Māori knowledge and everyday practices that assisted in protecting Māori from societal problems, such as domestic violence, began to dwindle. In contemporary New Zealand, Māori are over-represented in domestic violence statistics. Utilising an auto-ethnographic approach and case studies, our research focuses on five Māori men’s experiences within intimate relationships and whānau (extended family) life. A significant feature of this research is that it provides insights into the ways Māori men draw on their cultural ways-of-being to enhance intimate relationships and maintain bonds within whānau and community life to forge new ways-of-being. Such insights have the potential to inform preventative measures against domestic violence within Māori communities.

year: 2017