title: Estimating patterns and rates of coastal cliff retreat around Tauranga Harbour

authors: Garae, Camillia Pauline

subjects: rate of coastal cliff retreat

abstract: Cliffs are common around the shores of Tauranga Harbour, including in the urban areas. The existence of cliffs indicates a potential hazard to people living close to the cliff edge, as they imply both a tendency for the upper surfaces to erode, and for the debris to fall onto lower areas. To identify the relative risk around the harbour shoreline, it is useful to determine the rates and patterns of shoreline erosion.

This study initially determined the shoreline changes between 1943, 1982 and 2011 using a combination of aerial photograph analysis using Digital Shoreline Analysis System (DSAS), airborne LiDAR data and Laser scan data. Long term rate of retreat was determined for the study area with the use of digitised aerial photographs and DSAS applications. Cliff locations are often difficult to determine from aerial photographs due to shadows and vegetation obscuring the ground surface. Hence, LiDAR data were used to initially identify the cliff edge positions in 2011. These results were compared to the 2011 aerial photograph to assess how easily the cliff edge can be identified with the photographs. The inferred cliff edge from the 2011 aerial photograph was digitised in GIS, and the corresponding cliff edge for 1943 was also determined and digitised using stereopairs to aid cliff edge identification. The 1982 aerial photograph was scanned, georeferenced and shoreline digitised. Using the DSAS software, the rates were computed. However, this was also compared to other methods using the intersection points generated from DSAS. Laser scan surveys were conducted to determine surface volume changes to acquire short term rate of retreat at the cliff face. This analysis involved surveys carried out within a period from May 2014, July 2014 – November 2014. The data collected was compared to earlier laser scan data from September 2012 – July 2013 and LiDAR data from September 2011.

Several approaches were used to determine the best estimate of rate of retreat from the DSAS analyses. It was identified that the buffer end-point rate produced the best rate cliff retreat in the study area. The range of rate of retreat using this method was -0.2 ± 0.16 to 0.07 ± 0.16 m.y-1. It was also identified that the Matua Subgroup had the highest rate of erosion within the study area located at South west Matakana Island. The rate was lowest at East Pahoia Peninsula. Although laser scans were conducted only over a short period of time, comparing the dataset to earlier laser scan data a range of rates were obtained -0.01 to 0.02 m.y-1. Although rates were determined for both methods the errors were large and need to be considered.

text: Estimating patterns and rates of coastal cliff retreat around Tauranga Harbour Cliffs are common around the shores of Tauranga Harbour, including in the urban areas. The existence of cliffs indicates a potential hazard to people living close to the cliff edge, as they imply both a tendency for the upper surfaces to erode, and for the debris to fall onto lower areas. To identify the relative risk around the harbour shoreline, it is useful to determine the rates and patterns of shoreline erosion.

This study initially determined the shoreline changes between 1943, 1982 and 2011 using a combination of aerial photograph analysis using Digital Shoreline Analysis System (DSAS), airborne LiDAR data and Laser scan data. Long term rate of retreat was determined for the study area with the use of digitised aerial photographs and DSAS applications. Cliff locations are often difficult to determine from aerial photographs due to shadows and vegetation obscuring the ground surface. Hence, LiDAR data were used to initially identify the cliff edge positions in 2011. These results were compared to the 2011 aerial photograph to assess how easily the cliff edge can be identified with the photographs. The inferred cliff edge from the 2011 aerial photograph was digitised in GIS, and the corresponding cliff edge for 1943 was also determined and digitised using stereopairs to aid cliff edge identification. The 1982 aerial photograph was scanned, georeferenced and shoreline digitised. Using the DSAS software, the rates were computed. However, this was also compared to other methods using the intersection points generated from DSAS. Laser scan surveys were conducted to determine surface volume changes to acquire short term rate of retreat at the cliff face. This analysis involved surveys carried out within a period from May 2014, July 2014 – November 2014. The data collected was compared to earlier laser scan data from September 2012 – July 2013 and LiDAR data from September 2011.

Several approaches were used to determine the best estimate of rate of retreat from the DSAS analyses. It was identified that the buffer end-point rate produced the best rate cliff retreat in the study area. The range of rate of retreat using this method was -0.2 ± 0.16 to 0.07 ± 0.16 m.y-1. It was also identified that the Matua Subgroup had the highest rate of erosion within the study area located at South west Matakana Island. The rate was lowest at East Pahoia Peninsula. Although laser scans were conducted only over a short period of time, comparing the dataset to earlier laser scan data a range of rates were obtained -0.01 to 0.02 m.y-1. Although rates were determined for both methods the errors were large and need to be considered.

year: 2015

title: Coverpage and Contents

authors: Waikato Geological Society

abstract: Coverpage and Contents from Volume 2, Number 1, 1968 of Earth Science Journal.

text: Coverpage and Contents Coverpage and Contents from Volume 2, Number 1, 1968 of Earth Science Journal.

year: 1968

title: Listening to the voices of Year 13 Māori students: A case study in a New Zealand secondary school

authors: Kay, Joan-Marie

subjects: Maori Achievement

abstract: This research focuses on listening to the voices of Year 13 academically successful Māori students in a large, urban, mainstream, co-educational, decile 4, New Zealand secondary school. Traditionally, researchers have tended to emphasise the poor academic performance of Māori students in New Zealand. In contrast, this qualitative case study, however, seeks to understand what influences and motivates the academically successful Year 13 Māori students who have gained the National Certificate of Educational Achievement (NCEA) Level 2 and who returned to school to study for NCEA Level 3.

Semi structured interviews as conversations with all thirteen Māori students who had achieved NCEA Level 2 formed the basis of this research. Five of their parents, seven of their teachers and the principal were also interviewed.

The findings show that these students all stress the importance of their family, in particular, one family member or significant adult in their lives who valued education and supported the student, influencing and encouraging their motivation and self-efficacy. Building positive relationships with their teachers was the next strongest influence on their academic success followed closely by the positive influence of their friends. Self-motivation was mainly extrinsic. The students perceived that the principal had little effect on their individual achievement.

The teachers also acknowledge the importance of building positive relationships with their students and acknowledge the benefits of the reflective practice provided by the Te Kotahitanga project in highlighting this factor.

The findings suggest the excellent initiatives currently taking place in the school need to be continued or strengthened and that further interventions which target particular Māori students, rather than are global across the school, should be introduced.

text: Listening to the voices of Year 13 Māori students: A case study in a New Zealand secondary school This research focuses on listening to the voices of Year 13 academically successful Māori students in a large, urban, mainstream, co-educational, decile 4, New Zealand secondary school. Traditionally, researchers have tended to emphasise the poor academic performance of Māori students in New Zealand. In contrast, this qualitative case study, however, seeks to understand what influences and motivates the academically successful Year 13 Māori students who have gained the National Certificate of Educational Achievement (NCEA) Level 2 and who returned to school to study for NCEA Level 3.

Semi structured interviews as conversations with all thirteen Māori students who had achieved NCEA Level 2 formed the basis of this research. Five of their parents, seven of their teachers and the principal were also interviewed.

The findings show that these students all stress the importance of their family, in particular, one family member or significant adult in their lives who valued education and supported the student, influencing and encouraging their motivation and self-efficacy. Building positive relationships with their teachers was the next strongest influence on their academic success followed closely by the positive influence of their friends. Self-motivation was mainly extrinsic. The students perceived that the principal had little effect on their individual achievement.

The teachers also acknowledge the importance of building positive relationships with their students and acknowledge the benefits of the reflective practice provided by the Te Kotahitanga project in highlighting this factor.

The findings suggest the excellent initiatives currently taking place in the school need to be continued or strengthened and that further interventions which target particular Māori students, rather than are global across the school, should be introduced.

year: 2008