title: Observations of asymmetry in contrasting wave-and tidally-dominated environments within a meso-tidal basin: implications for estuarine morphological evolution

authors: Hunt, Stephen

subjects: tidal asymmetry

abstract: Tides are often considered to be the dominant hydrodynamic process within mesotidal estuaries although waves can also have a large influence on intertidal erosion rates. Here, we use a combination of hydrodynamic measurements and sediment deposition records to determine the conditions under which observed waves are “morphologically significant”, in which case they influence tidal and suspended sediment flux asymmetry and subsequently infilling over geomorphological timescales. Morphological significant conditions were evaluated using data from contrasting arms in a dendritic mesotidal estuary, in which the orientation of the arms relative to the prevailing wind results in a marked difference in wave conditions, deposition rates and morphology. By defining the morphological significance of waves as a product of the magnitude of bed shear stress and frequency of occurrence, even small (but frequently occurring) winds are shown to be capable of generating waves that are morphologically significant given sufficient fetch. In the arm in which fetch length is restricted, only stronger but rare storm events can influence sediment flux and therefore tides are more morphologically significant over longer timescales. Water depth within this mesotidal estuary is shown to be a critical parameter in controlling morphological significance; the rapid attenuation of short period waves with depth results in contrasting patterns of erosion occurring during neaps and accretion during springs.

text: Observations of asymmetry in contrasting wave-and tidally-dominated environments within a meso-tidal basin: implications for estuarine morphological evolution Tides are often considered to be the dominant hydrodynamic process within mesotidal estuaries although waves can also have a large influence on intertidal erosion rates. Here, we use a combination of hydrodynamic measurements and sediment deposition records to determine the conditions under which observed waves are “morphologically significant”, in which case they influence tidal and suspended sediment flux asymmetry and subsequently infilling over geomorphological timescales. Morphological significant conditions were evaluated using data from contrasting arms in a dendritic mesotidal estuary, in which the orientation of the arms relative to the prevailing wind results in a marked difference in wave conditions, deposition rates and morphology. By defining the morphological significance of waves as a product of the magnitude of bed shear stress and frequency of occurrence, even small (but frequently occurring) winds are shown to be capable of generating waves that are morphologically significant given sufficient fetch. In the arm in which fetch length is restricted, only stronger but rare storm events can influence sediment flux and therefore tides are more morphologically significant over longer timescales. Water depth within this mesotidal estuary is shown to be a critical parameter in controlling morphological significance; the rapid attenuation of short period waves with depth results in contrasting patterns of erosion occurring during neaps and accretion during springs.

year: 2016

title: New Zealand regions, 1986-2001: Labour market aspects of human capital

authors: Pool, Ian

subjects: labour force

abstract: This paper provides an analysis of labour force participation, full and part-time work and unemployment, over the 1986 – 2001 period. Using a non-conventional estimation technique devised for this paper, the paper also looks at discouraged worker effects. It points to growth in regional inequality and the worrying impact of negative labour market effects on ages 30- 44 years that are central to both the economic and family life of the nation. Using a custom designed method to assess “discouraged worker” effects, this paper shows that such effects are probably higher than the levels shown in official statistics that are constrained by narrowly defined criteria.

text: New Zealand regions, 1986-2001: Labour market aspects of human capital This paper provides an analysis of labour force participation, full and part-time work and unemployment, over the 1986 – 2001 period. Using a non-conventional estimation technique devised for this paper, the paper also looks at discouraged worker effects. It points to growth in regional inequality and the worrying impact of negative labour market effects on ages 30- 44 years that are central to both the economic and family life of the nation. Using a custom designed method to assess “discouraged worker” effects, this paper shows that such effects are probably higher than the levels shown in official statistics that are constrained by narrowly defined criteria.

year: 2006-02

title: Measuring Wellbeing for Public Policy in a Bi-Cultural Nation: Update from Aotearoa New Zealand

authors: Weijers, Dan M.

abstract: A presentation at Measuring Wellbeing in a Multicultural World: An Interdisciplinary Workshop, Conference held at ANU, Canberra, Australia and online

text: Measuring Wellbeing for Public Policy in a Bi-Cultural Nation: Update from Aotearoa New Zealand A presentation at Measuring Wellbeing in a Multicultural World: An Interdisciplinary Workshop, Conference held at ANU, Canberra, Australia and online

year: 2023-08-11