title: Sediment transport in the Firth of Thames mangrove forest, New Zealand

authors: Lovett, Nicola Jane

subjects: Sediment transport

abstract: Mangroves provide a unique habitat for many species.  In addition to being biologically significant ecosystems, mangroves help protect coastal areas through the dissipation of tidal currents and wave energy.  However, mangroves are unpopular with some communities in New Zealand and removal of them is often considered in management strategies.  In order to effectively manage these vegetated coastal areas and predict growth and/or decline of mangrove systems, it is necessary to have a detailed understanding of how the hydrodynamic processes within forests influence sediment transport and deposition.  

A 6-day long experiment was conducted in the Firth of Thames mangrove forest to examine hydrodynamic processes that influence sediment transport from the intertidal mudflat across the fringing region of the mangrove forest into the forest itself.  A unique deployment system was utilised to minimise environmental disturbance during the data collection process at 5 sites.  Site 1 was located on the mudflat and site 2 was in the fringe area (i.e. the boundary between flat and forest).  Sites 3 to 5 were located at increasing distances inside the forest.  Results indicate wave activity causes a net offshore flux of sediment at site 1 (approximately 850 kg/m2 over the duration of the experiment), contrary to expectations.  However, at all other sites, there was a net onshore flux of sediment from the fringe into the forest (maximum at site 4 of 113.3 kg/m2).  Minimal scour in the experiment area indicates that sediment is primarily supplied by advection from other regions of the system. 

Flocculation is a key process in cohesive sediment transport.  One of the aims of the study was to understand the controls on flocculation within this vegetated system. Despite difficulties inherent in measuring flocs, floc images were successfully collected from some sites.  An initial qualitative analysis performed on images from 2 sites (1 and 3) over 2 tides revealed a greater quantity of large flocs on the mudflat than in the forest and that in general, flocs were larger on the ebb tide.  These results imply that settling velocities on the mudflat are larger than within the forest and settling velocities are larger during ebb than flood tides.

text: Sediment transport in the Firth of Thames mangrove forest, New Zealand Mangroves provide a unique habitat for many species.  In addition to being biologically significant ecosystems, mangroves help protect coastal areas through the dissipation of tidal currents and wave energy.  However, mangroves are unpopular with some communities in New Zealand and removal of them is often considered in management strategies.  In order to effectively manage these vegetated coastal areas and predict growth and/or decline of mangrove systems, it is necessary to have a detailed understanding of how the hydrodynamic processes within forests influence sediment transport and deposition.  

A 6-day long experiment was conducted in the Firth of Thames mangrove forest to examine hydrodynamic processes that influence sediment transport from the intertidal mudflat across the fringing region of the mangrove forest into the forest itself.  A unique deployment system was utilised to minimise environmental disturbance during the data collection process at 5 sites.  Site 1 was located on the mudflat and site 2 was in the fringe area (i.e. the boundary between flat and forest).  Sites 3 to 5 were located at increasing distances inside the forest.  Results indicate wave activity causes a net offshore flux of sediment at site 1 (approximately 850 kg/m2 over the duration of the experiment), contrary to expectations.  However, at all other sites, there was a net onshore flux of sediment from the fringe into the forest (maximum at site 4 of 113.3 kg/m2).  Minimal scour in the experiment area indicates that sediment is primarily supplied by advection from other regions of the system. 

Flocculation is a key process in cohesive sediment transport.  One of the aims of the study was to understand the controls on flocculation within this vegetated system. Despite difficulties inherent in measuring flocs, floc images were successfully collected from some sites.  An initial qualitative analysis performed on images from 2 sites (1 and 3) over 2 tides revealed a greater quantity of large flocs on the mudflat than in the forest and that in general, flocs were larger on the ebb tide.  These results imply that settling velocities on the mudflat are larger than within the forest and settling velocities are larger during ebb than flood tides.

year: 2017

title: Letter to the Editor Re “Fractional Modeling and SOC Estimation of Lithium-ion Battery”

authors: Scott, Jonathan B.

abstract: Presents letters to the editor for this issue of the publication.

text: Letter to the Editor Re “Fractional Modeling and SOC Estimation of Lithium-ion Battery” Presents letters to the editor for this issue of the publication.

year: 2018

title: What do New Zealand picturebooks tell us about New Zealand national identity?

authors: Daly, Nicola

abstract: Jeffries (2004, p. 4) defines national identity as ' ... a shared sense of belonging of a group of people that depends on a common area of named place, a common set of beliefs and values, and positive feelings for a specific named geographical area'. In her examination of how New Zealand culture is portrayed in picturebooks published between 2000 and 2005, McNeur (2006) suggests that the visual and textual messages in children's picturebooks are an important contributor to the development of children's national identity. This paper describes the process of choosing a collection of 22 New Zealand children's picturebooks (known as the New Zealand PictureBook Collection) to reflect and represent diversity in New Zealand national identity, and analyses what these books tell us about the New Zealand national identity.

text: What do New Zealand picturebooks tell us about New Zealand national identity? Jeffries (2004, p. 4) defines national identity as ' ... a shared sense of belonging of a group of people that depends on a common area of named place, a common set of beliefs and values, and positive feelings for a specific named geographical area'. In her examination of how New Zealand culture is portrayed in picturebooks published between 2000 and 2005, McNeur (2006) suggests that the visual and textual messages in children's picturebooks are an important contributor to the development of children's national identity. This paper describes the process of choosing a collection of 22 New Zealand children's picturebooks (known as the New Zealand PictureBook Collection) to reflect and represent diversity in New Zealand national identity, and analyses what these books tell us about the New Zealand national identity.

year: 2016