title: Geologically controlled sandy beaches: Their geomorphology, morphodynamics and classification

authors: Gallop, Shari L.

subjects: Science & Technology

abstract: Beaches that are geologically controlled by rock and coral formations are the rule, not the exception. This paper reviews the current understanding of geologically controlled beaches, bringing together a range of terminologies (including embayed beaches, shore platform beaches, relict beaches, and perched beaches, among others) and processes, with the aim of exploring the multiple ways in which geology influences beach morphology and morphodynamics. We show how in addition to sediment supply, the basement geology influences where beaches will form by providing accommodation, and in the cross-shore, aspects of rock platform morphology such as elevation and slope are also important. Geologically controlled beaches can have significant variations in sediment coverage with seasons and storms, and geological controls have fundamental influences on their contemporary morphodynamics. This includes wave shadowing by headlands and rock/coral formations inducing strong alongshore gradients in wave energy, resulting in corresponding variations in morphodynamic beach state and storm response. Geologically-induced rip currents including shadow rips, deflection rips and mega-rips that can develop on embayed beaches during storms, are an integral feature of the nearshore circulation and morphodynamics of geologically controlled beaches. We bring these processes together by presenting a conceptual model of alongshore and cross-shore levels of geological control. In the longshore dimension, this ranges from beaches that are slightly embayed, through to highly embayed beaches where headlands dominate the entire beach morphodynamic response. In the cross-shore dimension, this ranges from beaches without discernible geological controls, through to relict beaches above the influence of the contemporary littoral zone. Given the prevalence of geologically controlled beaches along the world's coasts, it is paramount for coastal management to consider how these beaches differ from unconstrained beaches and avoid applying inappropriate models and tools, especially with our uncertain future climate.

text: Geologically controlled sandy beaches: Their geomorphology, morphodynamics and classification Beaches that are geologically controlled by rock and coral formations are the rule, not the exception. This paper reviews the current understanding of geologically controlled beaches, bringing together a range of terminologies (including embayed beaches, shore platform beaches, relict beaches, and perched beaches, among others) and processes, with the aim of exploring the multiple ways in which geology influences beach morphology and morphodynamics. We show how in addition to sediment supply, the basement geology influences where beaches will form by providing accommodation, and in the cross-shore, aspects of rock platform morphology such as elevation and slope are also important. Geologically controlled beaches can have significant variations in sediment coverage with seasons and storms, and geological controls have fundamental influences on their contemporary morphodynamics. This includes wave shadowing by headlands and rock/coral formations inducing strong alongshore gradients in wave energy, resulting in corresponding variations in morphodynamic beach state and storm response. Geologically-induced rip currents including shadow rips, deflection rips and mega-rips that can develop on embayed beaches during storms, are an integral feature of the nearshore circulation and morphodynamics of geologically controlled beaches. We bring these processes together by presenting a conceptual model of alongshore and cross-shore levels of geological control. In the longshore dimension, this ranges from beaches that are slightly embayed, through to highly embayed beaches where headlands dominate the entire beach morphodynamic response. In the cross-shore dimension, this ranges from beaches without discernible geological controls, through to relict beaches above the influence of the contemporary littoral zone. Given the prevalence of geologically controlled beaches along the world's coasts, it is paramount for coastal management to consider how these beaches differ from unconstrained beaches and avoid applying inappropriate models and tools, especially with our uncertain future climate.

year: 2020

title: Research laboratory survey

authors: Thomson, Kirsten

subjects: computer science

abstract: This report represents the results of a survey conducted by the University of Waikato Usability Laboratory of the research laboratories at the Department of Computer Science, The University of Waikato, Hamilton, New Zealand. The study was conducted on behalf of the Department of Computer Science. 
The goal of the research was to: Inform the development of future laboratories; Inform the process any of re-development of current laboratories; Provide information about the use and acceptance of the laboratories.

text: Research laboratory survey This report represents the results of a survey conducted by the University of Waikato Usability Laboratory of the research laboratories at the Department of Computer Science, The University of Waikato, Hamilton, New Zealand. The study was conducted on behalf of the Department of Computer Science. 
The goal of the research was to: Inform the development of future laboratories; Inform the process any of re-development of current laboratories; Provide information about the use and acceptance of the laboratories.

year: 2002-11

title: Boat electrofishing salvage of fish in the Lower Mangamahoe Dam reservoir

authors: Hicks, Brendan J.

abstract: The aim of the survey was to salvage fish from the Lower Mangamahoe Dam reservoir before dewatering and dam removal. We used the University of Waikato’s 4.5 m-long, aluminium-hulled electrofishing boat to catch a total of 140 fish weighing an estimated 37.0 kg along 8 fishing tracks sites on 24 February 2022. These tracks comprised 2,807 lineal m and 11,228 m2 in area. Shortfin eels (Anguilla australis) and common bullies (Gobiomorphus cotidianus) were the only fish species present. Mean density of eels caught was 2.9 fish 100 m–2 and mean biomass was 7.84 g m–2. The eels and bullies were transferred to sites downstream in the Waiwhakaiho River by iwi members of the two hapū - Ngāti Te Whiti and Ngāti Tawhirikura. Water clarity, expressed as black disc distance (BDD, 1.05 m), was good for a shallow lake, and water temperature and water conductivity were close to optimum for electrofishing. Poor water clarity can reduce the efficiency of electrofishing, so we left time after fishing each track for the sediment suspended by the propellor wash to sink before refishing a track.

text: Boat electrofishing salvage of fish in the Lower Mangamahoe Dam reservoir The aim of the survey was to salvage fish from the Lower Mangamahoe Dam reservoir before dewatering and dam removal. We used the University of Waikato’s 4.5 m-long, aluminium-hulled electrofishing boat to catch a total of 140 fish weighing an estimated 37.0 kg along 8 fishing tracks sites on 24 February 2022. These tracks comprised 2,807 lineal m and 11,228 m2 in area. Shortfin eels (Anguilla australis) and common bullies (Gobiomorphus cotidianus) were the only fish species present. Mean density of eels caught was 2.9 fish 100 m–2 and mean biomass was 7.84 g m–2. The eels and bullies were transferred to sites downstream in the Waiwhakaiho River by iwi members of the two hapū - Ngāti Te Whiti and Ngāti Tawhirikura. Water clarity, expressed as black disc distance (BDD, 1.05 m), was good for a shallow lake, and water temperature and water conductivity were close to optimum for electrofishing. Poor water clarity can reduce the efficiency of electrofishing, so we left time after fishing each track for the sediment suspended by the propellor wash to sink before refishing a track.

year: 2022