title: The vulnerability of Tongatapu coastal zone to local impacts of climate and sea level rise related risks

authors: Lao, Fine Faitehina Tutu'u

subjects: Climate change

abstract: Tongatapu coastal zone vulnerability assessment study was conducted to examine the degree of current and future risks of projected climate change and sea level rise on the coastal zone of the main island of the Kingdom of Tonga-Tongatapu. Inundation, and flooding hazards generated by tropical cyclone storm surges are the common threats to Tongatapu coastal towns and villages because of their low-lying settings. Flooding problems are exacerbated by the social trends of population growth and migration from the outer islands of the Kingdom, to Tongatapu the main island where the capital town of the Kingdom, Nuku'alofa is located. Other threats include beach erosion, saltwater intrusion, and seawater spraying of coastal vegetations and properties. A survey of the local people of Tongatapu, mapping of vulnerable areas with GIS, and using my local knowledge of the island coastal zone were the three methods were used to conduct this study. The main objective of this research was to assess the vulnerability of the coastal zone of Tongatapu to local impacts of inundation and flooding hazards associated with climate and sea-level rise related risks. The results of the survey indicated that more than 95% of the respondents agreed that the coastal zone of Tongatapu is vulnerable to inundation and flooding risks generated by tropical cyclones that visit Tongatapu coastal water every year, based on their recollection, knowledge, and experienced of the past storm events that hit Tongatapu. GIS work showed that those coastal towns and villages of Tongatapu that are located in areas less than 5 meter above sea level are vulnerable to the local impacts of inundation and flooding hazards. It is concluded that the yearly visited tropical cyclones to Tonga that are actually hit Tongatapu coastal zone had increasing the vulnerability of the coastal towns and villages of Tongatapu that are located in areas below 5 meters above sea level to inundation and flooding hazards associated with climate change and sea level rise related risks. Other possible cause might be the gradual uplifted of the south coast of Tongatapu due to ongoing earthquake activities in Tonga since the last 200 years. But in facts more research it has to be done to confirm this argument. The response to the local impacts of inundation and flooding hazards in the coastal zone of Tongatapu should be focused on adaptation, risk and hazard management.

text: The vulnerability of Tongatapu coastal zone to local impacts of climate and sea level rise related risks Tongatapu coastal zone vulnerability assessment study was conducted to examine the degree of current and future risks of projected climate change and sea level rise on the coastal zone of the main island of the Kingdom of Tonga-Tongatapu. Inundation, and flooding hazards generated by tropical cyclone storm surges are the common threats to Tongatapu coastal towns and villages because of their low-lying settings. Flooding problems are exacerbated by the social trends of population growth and migration from the outer islands of the Kingdom, to Tongatapu the main island where the capital town of the Kingdom, Nuku'alofa is located. Other threats include beach erosion, saltwater intrusion, and seawater spraying of coastal vegetations and properties. A survey of the local people of Tongatapu, mapping of vulnerable areas with GIS, and using my local knowledge of the island coastal zone were the three methods were used to conduct this study. The main objective of this research was to assess the vulnerability of the coastal zone of Tongatapu to local impacts of inundation and flooding hazards associated with climate and sea-level rise related risks. The results of the survey indicated that more than 95% of the respondents agreed that the coastal zone of Tongatapu is vulnerable to inundation and flooding risks generated by tropical cyclones that visit Tongatapu coastal water every year, based on their recollection, knowledge, and experienced of the past storm events that hit Tongatapu. GIS work showed that those coastal towns and villages of Tongatapu that are located in areas less than 5 meter above sea level are vulnerable to the local impacts of inundation and flooding hazards. It is concluded that the yearly visited tropical cyclones to Tonga that are actually hit Tongatapu coastal zone had increasing the vulnerability of the coastal towns and villages of Tongatapu that are located in areas below 5 meters above sea level to inundation and flooding hazards associated with climate change and sea level rise related risks. Other possible cause might be the gradual uplifted of the south coast of Tongatapu due to ongoing earthquake activities in Tonga since the last 200 years. But in facts more research it has to be done to confirm this argument. The response to the local impacts of inundation and flooding hazards in the coastal zone of Tongatapu should be focused on adaptation, risk and hazard management.

year: 2007

title: Sensitive pyroclastic soils in the Bay of Plenty, New Zealand: microstructure to failure mechanisms

authors: Moon, Vicki G.

subjects: sensitive soil

abstract: Sensitive soils derived from weathered rhyolitic pyroclastic materials are associated with many landslides in the Bay of Plenty. Undrained, consolidated static triaxial tests show contractive p’-q’ plots, strain-softening stress-strain behaviour coupled with rising pore water pressures, shear band formation after peak strength, and considerable strain softening. Cyclic triaxial tests confirm brittle failure and extensive softening of the soil. Pore pressure gradients developed during shearing initiate collapse of clay microstructures into shear zones; further excess pore pressure generation in the shear zone leads to progressive failure. Halloysite, a low-activity clay mineral, is associated with sensitive layers within the pyroclastic sequences. Mushroom cap–shaped spheroidal halloysite results in weak short-range interactions between exposed clay surfaces on incomplete spheroids. This weak bonding allows disassociation of clay aggregates during slope failure, leading to strain softening and the development of flow post-failure.

text: Sensitive pyroclastic soils in the Bay of Plenty, New Zealand: microstructure to failure mechanisms Sensitive soils derived from weathered rhyolitic pyroclastic materials are associated with many landslides in the Bay of Plenty. Undrained, consolidated static triaxial tests show contractive p’-q’ plots, strain-softening stress-strain behaviour coupled with rising pore water pressures, shear band formation after peak strength, and considerable strain softening. Cyclic triaxial tests confirm brittle failure and extensive softening of the soil. Pore pressure gradients developed during shearing initiate collapse of clay microstructures into shear zones; further excess pore pressure generation in the shear zone leads to progressive failure. Halloysite, a low-activity clay mineral, is associated with sensitive layers within the pyroclastic sequences. Mushroom cap–shaped spheroidal halloysite results in weak short-range interactions between exposed clay surfaces on incomplete spheroids. This weak bonding allows disassociation of clay aggregates during slope failure, leading to strain softening and the development of flow post-failure.

year: 2017

title: “I learned quite a lot of the Maths stuff now that I think of it”: Māori Medium Students reflecting on their Initial Teacher Education

authors: Hawera, Ngārewa

subjects: initial teacher education

abstract: Research involving preservice or initial teacher education (ITE) indicates that mathematics education is a vital component of study. Little is known however, of indigenous student views of their compulsory mathematics education courses for a teaching degree. This research contributes to that knowledge space as it explores Māori medium ITE students’ perceptions of mathematics education in Aotearoa New Zealand. A thematic and qualitative analysis of a focused group discussion provides insights into key factors that students reported as significant links between their university and practicum experiences (teaching practice in schools). Some suggestions for strengthening that programme were also expressed. Findings indicate that factors linked to teacher ‘cultural competencies’, including an ethic of care, respectful relationships, revision of content knowledge, language learning, assessment practices, exposure to different ideas and planning and pedagogy were important. Navigating student-mentor teacher tensions as well as clarifying the significance of ideas in texts were highlighted as areas for strengthening. Mathematics educators preparing students for indigenous primary school settings may find this study useful.

text: “I learned quite a lot of the Maths stuff now that I think of it”: Māori Medium Students reflecting on their Initial Teacher Education Research involving preservice or initial teacher education (ITE) indicates that mathematics education is a vital component of study. Little is known however, of indigenous student views of their compulsory mathematics education courses for a teaching degree. This research contributes to that knowledge space as it explores Māori medium ITE students’ perceptions of mathematics education in Aotearoa New Zealand. A thematic and qualitative analysis of a focused group discussion provides insights into key factors that students reported as significant links between their university and practicum experiences (teaching practice in schools). Some suggestions for strengthening that programme were also expressed. Findings indicate that factors linked to teacher ‘cultural competencies’, including an ethic of care, respectful relationships, revision of content knowledge, language learning, assessment practices, exposure to different ideas and planning and pedagogy were important. Navigating student-mentor teacher tensions as well as clarifying the significance of ideas in texts were highlighted as areas for strengthening. Mathematics educators preparing students for indigenous primary school settings may find this study useful.

year: 2017