title: Extent of seagrass in Tauranga Harbour: a comparison of satellite automated classification versus manual delineation of aerial imagery

authors: Shao, Zhanchao

abstract: This report outlines a comprehensive analysis of seagrass extent in Tauranga Harbour, New Zealand, using advanced remote sensing techniques. It compares two key methods: satellite-based supervised classification using Random Forest, and manual delineation via aerial photography. The research focuses on mapping the spatial and temporal changes in seagrass habitats, particularly the native species Zostera muelleri, from 1959 to 2024. Complementary to the satellite-based classification method, an easy-to-use graphical user interface (GUI) was developed, enabling users to efficiently access satellite imagery and generate detailed habitat maps.
The supervised classification using Random Forest proved effective for detecting seagrass habitats, achieving high accuracy (0.92 for Sentinel-2 and 0.88 for Landsat imagery). Despite occasional misclassifications, particularly in areas with high chlorophyll concentrations (i.e., the Tauranga Harbour sub-estuaries), the method provided a more time-efficient and scalable alternative to manual delineation. Aerial photography and manual mapping served as an important comparison but are less efficient in capturing less visible seagrass areas in deeper water or fragmented meadows.

text: Extent of seagrass in Tauranga Harbour: a comparison of satellite automated classification versus manual delineation of aerial imagery This report outlines a comprehensive analysis of seagrass extent in Tauranga Harbour, New Zealand, using advanced remote sensing techniques. It compares two key methods: satellite-based supervised classification using Random Forest, and manual delineation via aerial photography. The research focuses on mapping the spatial and temporal changes in seagrass habitats, particularly the native species Zostera muelleri, from 1959 to 2024. Complementary to the satellite-based classification method, an easy-to-use graphical user interface (GUI) was developed, enabling users to efficiently access satellite imagery and generate detailed habitat maps.
The supervised classification using Random Forest proved effective for detecting seagrass habitats, achieving high accuracy (0.92 for Sentinel-2 and 0.88 for Landsat imagery). Despite occasional misclassifications, particularly in areas with high chlorophyll concentrations (i.e., the Tauranga Harbour sub-estuaries), the method provided a more time-efficient and scalable alternative to manual delineation. Aerial photography and manual mapping served as an important comparison but are less efficient in capturing less visible seagrass areas in deeper water or fragmented meadows.

year: 2024-11-28

title: Book Review: Making a moral society: Ethics and the state in Meiji Japan

authors: Swale, Alistair

subjects: book review

abstract: This article reviews the book: “Making a moral society: Ethics and the state in Meiji Japan”, by Richard M. Reitan.

text: Book Review: Making a moral society: Ethics and the state in Meiji Japan This article reviews the book: “Making a moral society: Ethics and the state in Meiji Japan”, by Richard M. Reitan.

year: 2011

title: Testing a suicidal ideation-to-action framework among Queer and Takatāpui people in Aotearoa New Zealand: An examination of the three-step theory

authors: Schimanski, Irie

abstract: The three-step theory (3ST) of suicide is well-established in the general population and shows promise for explaining suicidal ideation among Queer samples. This study examined the applicability of the 3ST using data from 250 Queer (n = 213) and Takatāpui (n = 37) people aged 18-74 living in Aotearoa New Zealand. The analytic approach entailed hierarchical multiple regression, ANOVA, t-tests, and logistic regression. Step-one was partially supported, with discrimination and hopelessness independently associated with suicidal ideation, but not their interaction. Step-two was fully supported, showing social support associated with lower suicidal ideation when social support exceeded discrimination, compared with the inverse. Full support for step-three was observed, finding higher self-harm among participants with histories of attempted suicide than those who had never attempted. An adapted version of the 3ST for Queer and Takatāpui people is presented, offering novel approaches to testing the ideation-to-action framework with these communities.

text: Testing a suicidal ideation-to-action framework among Queer and Takatāpui people in Aotearoa New Zealand: An examination of the three-step theory The three-step theory (3ST) of suicide is well-established in the general population and shows promise for explaining suicidal ideation among Queer samples. This study examined the applicability of the 3ST using data from 250 Queer (n = 213) and Takatāpui (n = 37) people aged 18-74 living in Aotearoa New Zealand. The analytic approach entailed hierarchical multiple regression, ANOVA, t-tests, and logistic regression. Step-one was partially supported, with discrimination and hopelessness independently associated with suicidal ideation, but not their interaction. Step-two was fully supported, showing social support associated with lower suicidal ideation when social support exceeded discrimination, compared with the inverse. Full support for step-three was observed, finding higher self-harm among participants with histories of attempted suicide than those who had never attempted. An adapted version of the 3ST for Queer and Takatāpui people is presented, offering novel approaches to testing the ideation-to-action framework with these communities.

year: 2025-08-01