title: Model Development for Seasonal Forecasting of Hydro Lake Inflows in the Upper Waitaki Basin, New Zealand

authors: Purdie, Jennifer Margaret

subjects: Seasonal forecasting

abstract: Approximately 60% of New Zealand's electricity is produced from hydro generation. The Waitaki River catchment is located in the centre of the South Island of New Zealand, and produces 35-40% of New Zealand's electricity. Low inflow years in 1992 and 2001 resulted in the threat of power blackouts, and a national demand for electricity that is currently growing at 2 to 5% a year gives strong justification for better management of the hydro resource. Improved seasonal rainfall and inflow forecasts will result in the better management of the water used in hydro generation on a seasonal basis. 

Seasonal rainfall forecasting has been the focus of much international research in recent years, but seasonal inflow forecasting is in its relative infancy. Researchers have stated that key directions for both fields are to decrease the spatial scale of forecast products, and to tailor forecast products to end user needs, so as to provide more relevant and targeted forecasts, which will hopefully decrease the enormous socio-economic costs of climate fluctuations.

This study calibrated several season ahead lake inflow and rainfall forecast models for the Waitaki river catchment, using statistical techniques to quantify relationships between land-ocean-atmosphere state variables and seasonally lagged inflows and rainfall. Techniques included principal components analysis and multiple linear regression, with cross-validation techniques applied to estimate model error. 

Many of both the continuous and discrete format models calibrated in this study predict anomalously wet and dry seasons better than random chance, and better than the long term mean as a predictor. 95% confidence limits around most model predictions in this study offer significant skill when compared with the range of all probable inflows (based on the 80 year recording history in the catchment). 

Models predicting winter Lake Pukaki inflows are those with the strongest predictive relationships in this study. Spring and summer predictions were generally less skilful than those for winter and autumn. Inflows could be predicted with some skill in winter and summer, but not rainfall, and rainfall could be predicted with some skill in autumn and spring, but not inflows. Models predicting inflows and rainfall for different seasons in this study use very different sets of predictor variables to accomplish their seasonal predictability. This may be related to the significant seasonal snow storage in the catchment, so that other factors such as temperature and the number of north-westerly storms may have a large part to play in the magnitude of inflows. Similarly, predicting the same dependent variable but for different seasons led to different contributing variables, leading to the conclusion that different wider physical causative mechanisms are behind the predictability in different seasons, and that they too should be studied separately in any future research. SST5 (sea surface temperature to the north of New Zealand) was found to have more relevance than any other predictor in predicting Waitaki river inflows and rainfall in any season. 

The models calibrated with SOI and IPO included as predictor variables were almost invariably worse in their predictive skill than those without, and the list of the most important predictor variables in all models did not include equatorial sea surface temperatures, sea level pressures, or 700hpa geopotential height variables. The conclusion from these findings is that equatorial ocean-atmosphere state variables do not have significant relationships with season ahead inflows and rainfall in the South Island of New Zealand.

Seasonal climate forecasting on single catchment scale, and focussed to end user needs, is possible with some skill, at least in the South Island of New Zealand.

text: Model Development for Seasonal Forecasting of Hydro Lake Inflows in the Upper Waitaki Basin, New Zealand Approximately 60% of New Zealand's electricity is produced from hydro generation. The Waitaki River catchment is located in the centre of the South Island of New Zealand, and produces 35-40% of New Zealand's electricity. Low inflow years in 1992 and 2001 resulted in the threat of power blackouts, and a national demand for electricity that is currently growing at 2 to 5% a year gives strong justification for better management of the hydro resource. Improved seasonal rainfall and inflow forecasts will result in the better management of the water used in hydro generation on a seasonal basis. 

Seasonal rainfall forecasting has been the focus of much international research in recent years, but seasonal inflow forecasting is in its relative infancy. Researchers have stated that key directions for both fields are to decrease the spatial scale of forecast products, and to tailor forecast products to end user needs, so as to provide more relevant and targeted forecasts, which will hopefully decrease the enormous socio-economic costs of climate fluctuations.

This study calibrated several season ahead lake inflow and rainfall forecast models for the Waitaki river catchment, using statistical techniques to quantify relationships between land-ocean-atmosphere state variables and seasonally lagged inflows and rainfall. Techniques included principal components analysis and multiple linear regression, with cross-validation techniques applied to estimate model error. 

Many of both the continuous and discrete format models calibrated in this study predict anomalously wet and dry seasons better than random chance, and better than the long term mean as a predictor. 95% confidence limits around most model predictions in this study offer significant skill when compared with the range of all probable inflows (based on the 80 year recording history in the catchment). 

Models predicting winter Lake Pukaki inflows are those with the strongest predictive relationships in this study. Spring and summer predictions were generally less skilful than those for winter and autumn. Inflows could be predicted with some skill in winter and summer, but not rainfall, and rainfall could be predicted with some skill in autumn and spring, but not inflows. Models predicting inflows and rainfall for different seasons in this study use very different sets of predictor variables to accomplish their seasonal predictability. This may be related to the significant seasonal snow storage in the catchment, so that other factors such as temperature and the number of north-westerly storms may have a large part to play in the magnitude of inflows. Similarly, predicting the same dependent variable but for different seasons led to different contributing variables, leading to the conclusion that different wider physical causative mechanisms are behind the predictability in different seasons, and that they too should be studied separately in any future research. SST5 (sea surface temperature to the north of New Zealand) was found to have more relevance than any other predictor in predicting Waitaki river inflows and rainfall in any season. 

The models calibrated with SOI and IPO included as predictor variables were almost invariably worse in their predictive skill than those without, and the list of the most important predictor variables in all models did not include equatorial sea surface temperatures, sea level pressures, or 700hpa geopotential height variables. The conclusion from these findings is that equatorial ocean-atmosphere state variables do not have significant relationships with season ahead inflows and rainfall in the South Island of New Zealand.

Seasonal climate forecasting on single catchment scale, and focussed to end user needs, is possible with some skill, at least in the South Island of New Zealand.

year: 2007

title: Contemporary relevance of Anne Moody, Black studies and imprisoned Black intellectual thought

authors: Norris, Adele N.

subjects: Anne Moody

abstract: Anne Moody’s 1968 autobiographical text, Coming of Age in Mississippi, is receiving increased interest during this current moment of legislated anti-Blackness, most observable in the removal/outlawing of Black history and thought. Moody’s early life in the Deep South during the 1940s-1950s and as a foot soldier in the Civil Rights Movement inform how we understand the continuity of anti-blackness and racial terror. Glen Conley, an imprisoned citizen, examines and teaches Anne Moody within a Mississippi prison context. While her book is used across several academic disciplines, the study of Moody within the prison context is not well known. Conley’s political poetry explores Moody’s life and text, bringing renewed attention to themes of Black mental health, survival, and resistance under a harsh U.S. Southern regime. Using a prison-praxis framework, this paper centers the knowledge production from the civically dead (imprisoned population), which allows for broader insights into themes of racialized confinement, criminalization and surveillance. Thus, this essay situates Conley’s scholarship within the lineage of Black imprisoned radical tradition where he draws attention to Moody’s prescient voice during a political climate of overt forms of legislated anti-Blackness and systemic erasure.

text: Contemporary relevance of Anne Moody, Black studies and imprisoned Black intellectual thought Anne Moody’s 1968 autobiographical text, Coming of Age in Mississippi, is receiving increased interest during this current moment of legislated anti-Blackness, most observable in the removal/outlawing of Black history and thought. Moody’s early life in the Deep South during the 1940s-1950s and as a foot soldier in the Civil Rights Movement inform how we understand the continuity of anti-blackness and racial terror. Glen Conley, an imprisoned citizen, examines and teaches Anne Moody within a Mississippi prison context. While her book is used across several academic disciplines, the study of Moody within the prison context is not well known. Conley’s political poetry explores Moody’s life and text, bringing renewed attention to themes of Black mental health, survival, and resistance under a harsh U.S. Southern regime. Using a prison-praxis framework, this paper centers the knowledge production from the civically dead (imprisoned population), which allows for broader insights into themes of racialized confinement, criminalization and surveillance. Thus, this essay situates Conley’s scholarship within the lineage of Black imprisoned radical tradition where he draws attention to Moody’s prescient voice during a political climate of overt forms of legislated anti-Blackness and systemic erasure.

year: 2025-12-31

title: Maori identity within whanau: A review of literature.

authors: Moeke-Pickering, Taima Materangatira

subjects: Maori identity

abstract: The study of identities is an enormous and complex undertaking. Research on identity formation has revealed a clear link between family practices and identity development. In traditional Maori times, the whanau was the place where initial teaching and socialisation of things Maori took place. While there is no single exact measure of what constitutes Maori identity (Durie, 1994), that Maori identity is still being asserted today means that the shaping of Maori identity is still occurring. Rather than attempt to cover all aspects of how Maori shape their identities, I have chosen to focus on the shaping of Maori identity within whanau. Given that this paper is about both Maori identity and whanau identity it seemed logical to review and examine the literature surrounding these two notions. In this paper I also discuss the ecological threats and supports that influenced Maori and whanau identity. Then I review literature on whanau identity from traditional and contemporary works, and explore the concept of whanau identity as a management framework. The literature on whanau does not vary from what Maori authors have expressed regarding their conceptualisations of Maori identity. The tribal structures, descent and cultural practices provide integral pathways through which whanau and Maori identity can be developed and maintained. What is of significance, is that the formation of a secure whanau identity is likely to contribute toward an overall stable Maori identity. Creating an environment where a sense of secure wellbeing among members of a whanau is nurtured, leads to members constructing a whanau and Maori identity that is meaningful to them in their lives.

text: Maori identity within whanau: A review of literature. The study of identities is an enormous and complex undertaking. Research on identity formation has revealed a clear link between family practices and identity development. In traditional Maori times, the whanau was the place where initial teaching and socialisation of things Maori took place. While there is no single exact measure of what constitutes Maori identity (Durie, 1994), that Maori identity is still being asserted today means that the shaping of Maori identity is still occurring. Rather than attempt to cover all aspects of how Maori shape their identities, I have chosen to focus on the shaping of Maori identity within whanau. Given that this paper is about both Maori identity and whanau identity it seemed logical to review and examine the literature surrounding these two notions. In this paper I also discuss the ecological threats and supports that influenced Maori and whanau identity. Then I review literature on whanau identity from traditional and contemporary works, and explore the concept of whanau identity as a management framework. The literature on whanau does not vary from what Maori authors have expressed regarding their conceptualisations of Maori identity. The tribal structures, descent and cultural practices provide integral pathways through which whanau and Maori identity can be developed and maintained. What is of significance, is that the formation of a secure whanau identity is likely to contribute toward an overall stable Maori identity. Creating an environment where a sense of secure wellbeing among members of a whanau is nurtured, leads to members constructing a whanau and Maori identity that is meaningful to them in their lives.

year: 1996-01-01