Giovanni Coco

Giovanni Coco
University of Auckland

PhD

About

232
Publications
47,308
Reads
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5,818
Citations
Citations since 2016
93 Research Items
3912 Citations
20162017201820192020202120220200400600
20162017201820192020202120220200400600
20162017201820192020202120220200400600
20162017201820192020202120220200400600
Additional affiliations
May 2011 - May 2014
Universidad de Cantabria
Position
  • AGL Research Fellow

Publications

Publications (232)
Article
Wave climatologies from historical and projected simulations of the ACCESS1.0, MIROC5 and CNRM-CM5 Global Circulation Models (GCM) were sourced from the Coordinated Ocean Wave Climate Project (COWCLIP) and downscaled using the SWAN wave model. Biases between GCM's historical simulations and a regional hindcast were assessed, and the two best perfor...
Article
Emerging research shows that microplastic pollution could be impacting seafloor ecosystem function, but this has been primarily demonstrated without environmental and ecological context. This causes uncertainty in the real-world effects of microplastic pollution and leaves out essential information guiding policy and mitigation. In this study, we t...
Article
Understanding and predicting the geomorphological response of fluvial and tidal channels to bank retreat underpins the robust management of water courses and the protection of wetlands.
Article
Full-text available
Salt marshes play a key role in attenuating wave energy and promoting sedimentation necessary to potentially adapt to sea level rise. The changes in the soil surface elevation, as a result of spatially and temporally varied sedimentation pattern, affect the hydrodynamics, marsh edge extension and so the sedimentation rate. Little attention has yet...
Article
Estimating sediment budget is a challenge that requires understanding the morphological relationship between the subaerial beach and the upper and lower shoreface. Based on a unique dataset of monthly measured topographic and bathymetric measurements, this study describes the morphodynamics of the subaerial and subtidal sections of a highly-dynamic...
Article
Full-text available
Bank retreat plays a fundamental role in fluvial and estuarine dynamics. It affects the cross-sectional evolution of channels, provides a source of sediment, and modulates the diversity of habitats. Understanding and predicting the geomorphological response of fluvial/tidal channels to external driving forces underpins the robust management of wate...
Article
The global COVID-19 pandemic has seen extended lockdowns, isolation periods and travel restrictions across many countries around the world since early 2020. Some countries, such as Australia and New Zealand, closed their international borders in early 2020 preventing researchers travelling to other parts of the world. To facilitate the exposure of...
Article
Tropical cyclones are associated with extreme winds, waves, and storm surge, being among most destructive natural phenomena. Developing capability for a rapid impact estimate is crucial for coastal applications and risk preparedness. When predicting waves characteristics associated to tropical cyclones, the traditional approach involves a two‐step...
Article
Full-text available
Field studies suggest that storms can considerably affect the morphology, sedimentology and bedding structure of tidal flat wetlands because of their high-energy, while numerical modeling studies unravelling the underlying mechanisms remain rare. With a tidal flat of the Changjiang Delta, China as a reference site, this study explores the role of s...
Article
The historical, present, and projected future risk of coastal flooding necessitates measures to protect coastal communities and environments, including using natural defences such as mangroves. Estimates of extent of flood protection provided by mangrove forests range widely, probably because of differences in growth characteristic of trees combine...
Article
This paper reports a scientific inquiry carried out within the management process of an exceptional accumulation of reeds and seagrasses that took place in December 2019 on Poetto beach (Cagliari, southern Sardinia, western Mediterranean). The magnitude of the event raised concern within the local community and tourism service providers especially...
Chapter
Coastal landforms can sometimes result in unique and visually mesmerizing spatially-organized patterns. Different spatial patterns develop over scales ranging from centimeters to tens of kilometers, and are observed at the shoreline (e.g., ripples, beach cusps, shoreline undulations), in the surf zone (e.g., crescentic or multiple sandbars) and eve...
Article
Full-text available
As dunes move along the riverbed, they change in size, shape, and arrangement. This involves sediment fluxes on top of the net downstream motion of the dune field, but how much dune dynamics affect total sediment flux remains unclear. In this study, we obtain high‐resolution and high‐frequency digital elevation models of migrating submerged dunes i...
Article
Full-text available
p>Researchers have extensively investigated the back-barrier islands morphodynamics using numerical methods. However, the influence of rocky mouth islands, which may be submerged by sea-level rise, has been rarely explored. Using the Dongshan Bay in southern China as a reference, this study numerically explores the long-term morphodynamic effect of...
Article
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Sandy beaches comprise approximately 31% of the world's ice-free coasts. Sandy coastlines around the world are continuously adjusting in response to changing waves and water levels at both short (storm) and long (climate-driven, from El-Nino Southern Oscillation to sea level rise) timescales. Managing this critical zone requires robust, advanced to...
Article
Full-text available
Marine microplastics accumulate in sediments but impacts on ecosystem functions are poorly understood. Microplastics interactions with stabilizing benthic flora/fauna or biostabilization processes, have not been fully investigated, yet this is critical for unravelling microplastics effects on ecosystem-scale processes and functions. This is also vi...
Article
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Understanding the interactions between dune systems and beaches is critical to determining the short‐term shoreline response and the long‐term resilience. In this study, almost 15 years of monthly beach/dune measurements were analyzed for three different profiles at Vougot Beach, France to understand and predict shoreline changes from intra‐annual to...
Article
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Overhanging riverbank stability is a key feature of bank retreat. Although different mechanisms of bank collapse have been studied by many researchers, prediction of cantilever failure patterns and understanding of three-dimensional failure surfaces continue to puzzle scientists. To address this problem, we conducted laboratory experiments and nume...
Article
A high resolution partitioned wave hindcast of New Zealand waters is presented together with validation results against 9 buoy deployments that are representative of the local wave climate. An analysis of integrated and partitioned mean wave parameters was conducted together with a study of the correlation between wave height anomalies and atmosphe...
Article
Full-text available
The use of power law forms to describe hydraulic geometry is a classic subject with a history of over 70 years. Two distinct forms of power laws have been proposed: at-a-station hydraulic geometry (AHG) and downstream hydraulic geometry (DHG). Although the utility of these semiempirical expressions is widely recognized, they remain poorly understoo...
Preprint
Full-text available
The morphodyamics of back-barrier tidal basins have been extensively investigated by numerical modelling, but the influence of mouth islands (which may be submerged under future sea level rise) has been rarely explored. Using the Dongshan Bay in southern China as a reference site, we explore numerically the effects of geological constraints (i.e.,...
Article
Full-text available
Reliable predictions and accompanying uncertainty estimates of coastal evolution on decadal to centennial time scales are increasingly sought. So far, most coastal change projections rely on a single, deterministic realization of the unknown future wave climate, often derived from a global climate model. Yet, deterministic projections do not accoun...
Article
Coastal sediments, where microplastics (MPs) accumulate, support benthic microalgae (BMA) that contribute to ecosystem functions such as primary production, nutrient recycling and sediment biostabilization. The potential interactions between MPs, BMA and associated properties and functions remain poorly understood. To examine these interactions, a...
Article
Full-text available
Meander migration results from the interaction between inner bank accretion and outer bank erosion/collapse. This interaction has been usually treated as a long-term average of a sequence of erosion events determined by flow hydrographs. Little attention has been paid to the role that individual bank collapse events play on meander evolution. To fi...
Article
Full-text available
Wave‐induced flooding is a major coastal hazard for the low‐lying atolls of the Pacific. These flooding events are expected to increase over time, which may cause significant coastal damage in some locations. Coastal flooding analysis (forensic or forecasted) is particularly challenging in these small islands due to the co‐occurrence of several swe...
Article
Understanding sediment sorting and bedding dynamics has high value to unravelling the mechanisms underlying geomorphological, geological, ecological and environmental imprints of tidal wetlands and hence to predicting their future changes. Using the Nanhui tidal flat on the Changjiang (Yangtze) Delta, China, as a reference site, this study establis...
Article
Full-text available
The processes underlying sediment transport mechanics are still debated. Here, we present novel ensemble particle bedload measurements, obtained with high‐frequency imaging of particle velocities and activity over various bedform migration stages. We show that the bedload particle flux quickly responds to the unsteady non‐uniform flow over the bed....
Article
Full-text available
We performed a three‐dimensional high‐resolution Large Eddy Simulation using a sinusoidal ripple‐like bedform geometry with spacing and amplitude consistent with equilibrium conditions under the prescribed oscillatory forcing. The simulation results are validated qualitatively and quantitatively with previous laboratory experiments and numerical si...
Article
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Sediment‐stabilizing and ‐destabilizing organisms, i.e. microphytobenthos (biofilms) and macrozoobenthos (bioturbators), affect the erodibility of muddy sediments, potentially altering large‐scale estuarine morphology. Using a novel eco‐morphodynamic model of an idealized estuary, we investigate eco‐engineering effects of microphytobenthos and two...
Article
Plastic pollution continues to seep into natural and pristine habitats. Emerging laboratory-based research has evoked concern regarding plastic’s impact on ecosystem structure and function, the essence of the ecosystem services that supports our life, wellbeing, and economy. These impacts have yet to be observed in nature where complex ecosystem in...
Chapter
Researchers use models to understand and forecast morphodynamic evolution in a variety of coastal contexts: surf zone dynamics including the short-term evolution of the nearshore seabed and shoreline; the longer-term evolution of coastline planview shapes, and associated shoreline change; and the evolution of the cross-shore profiles of barrier and...
Article
Full-text available
We present an ensemble Kalman filter shoreline change model to predict long-term coastal evolution due to waves, sea-level rise, and other natural and anthropogenic processes responsible for sediment transport. The model utilizes ensemble simulations to improve both reliability (via data assimilation) and uncertainty quantification. Coastal change...
Article
The landscape setting for an estuary varies widely and is an important aspect of determining how they evolve. This paper focusses on alluvial estuaries in river valleys and how they respond to sea level rise. We examine the implications of marine transgression, as a response to sea level rise, where the estuary moves upwards and landwards to mainta...
Conference Paper
Edge waves are coastal waves trapped near the shore by reflection and refraction. Previous studies show the clear excitation mechanism of edge waves under monochromatic wave conditions via phase locking and nonlinear growth. However, how efficiently the mechanism would work under random incident waves remains unclear. This study compares laboratory...
Article
Full-text available
The description of the geomorphic characteristics in power law forms has been the subject of research, over the past 70 years, and has become the cornerstone of regime theory. However, just why power functions should represent such geomorphic relationships remains poorly understood. Hence, differences in the values of the regime exponents observed...
Article
Coastal hazards often result from the combination of different simultaneous oceanographic processes that occur at multiple spatial and temporal scales. To predict coastal flooding and erosion, it is necessary to accurately represent hydrodynamic conditions. For this reason, here we present a stochastic, climate based wave emulator that provides the...
Article
Full-text available
Microfibers often dominate sediment microplastic samples but little is known about their ecological effects on benthic organisms and functions. Polyethylene terephthalate (PET) microfibers were added to 36 sediment chambers at 6 concentrations (0-0.5 g kg-1 sediment) to assess the effects on microphytobenthos (MPB), a key deposit-feeding bivalve, M...
Article
Full-text available
Microfibers often dominate sediment microplastic samples, but little is known about their ecological effects on benthic organisms and functions. Polyethylene terephthalate) (PET) microfibers were added to 36 sediment chambers at six concentrations (0-0.5 g kg-1 sediment) to assess the effects on microphytobenthos (MPB), a key deposit-feeding bivalv...
Article
Full-text available
Passarella, M.; Ruju, A.; De Muro, S., and Coco, G., 2020. Horizontal runup and seagrass beach cast-litters: Modelling and observations. In: Malvárez, G. and Navas, F. (eds.), Global Coastal Issues of 2020. Journal of Coastal Research, Special Issue No. 95, pp. 143-147. Coconut Creek (Florida), ISSN 0749-0208. We collected measurements of wave-driv...
Article
Full-text available
Double sandbar systems often characterize the surf zone of wave-dominated beaches and display a variety of poorly explained spatial configurations. Here, we explore the morphodynamic stability of double-barred beaches using a model based on linear stability analysis. Surf zone hydrodynamics are described by coupling depth and wave-averaged conserva...
Article
Full-text available
We set up a laboratory experiment to reproduce flow-induced bank erosion and bank collapse, and to study the role of bank height (Hb) and near-bank water depth (Hw) on bank stability. Five laboratory experiments were conducted in a plexiglass-walled soil tank, using silt collected from natural tidal channel banks (D50 = 75m). During each experimen...
Article
Wave-generated ripples are macroscopic roughness elements that influence fluid flow and sediment transport. For a major group of ripples (orbital ripples), morphology (height and wavelength) is set by the wave conditions. In natural conditions, where wave forcing is highly variable, ripple morphology is frequently changing. We investigate the rate...
Article
When modelling urban expansion dynamics, cellular automata models focus mostly on the physical environments and cell neighbours, but ignore the ‘human’ aspect of the allocation of urban expansion cells. This limitation is overcome here using an intelligent self-adapting multiscale agent-based model. To simulate the urban expansion of Auckland, New...
Article
Predicting recreational water quality is one of the most difficult tasks in water management with major implications for humans and society. Many data-driven models have been used to predict water quality indicators to allow a real time assessment of public health risk. This assessment is most commonly based on Faecal Indicator Bacteria (FIB), with...
Article
The role of three-dimensionality (3D) in modulating both flow and sediment transport remains poorly understood. 3D bed elevation measurements are difficult to obtain due to irregular dune shapes and submergence. Using photogrammetric tools for topographic reconstruction has become popular in surface studies, yet water refraction makes through-water...
Presentation
Edge waves are infragravity waves trapped by refraction near the shoreline that propagate in the alongshore direction. For monochromatic incident waves, mode-zero subharmonic edge waves are more likely to grow. However, the role of random incident waves on the growth of edge waves remains unknown. Here we show that the growth of edge waves under ra...
Article
Full-text available
Beaches around the world continuously adjust to daily and seasonal changes in wave and tide conditions, which are themselves changing over longer time-scales. Different approaches to predict multi-year shoreline evolution have been implemented; however, robust and reliable predictions of shoreline evolution are still problematic even in short-term...
Chapter
The development of rhythmic patterns in the surf zone has challenged coastal scientists for over a century. A variety of sandbar patterns develop in the surf zone including multiple sandbars, crescentic sandbars and transverse sandbars. This chapter describes existing observations focusing on how different settings and wave conditions can lead to d...
Chapter
Beach cusps, alongshore sandwaves, and cuspate-cape coastlines provide three examples of shoreline or coastline patterns that have, in recent decades, been re-explained as self-organised, or emergent phenomena. In each case, previous explanations involved ‘forcing templates’—either patterns in the hydrodynamic forcing that could be imprinted in the...
Preprint
Full-text available
Abstract. The morphodynamic stability of double-barred beaches is explored using a numerical model based on linear stability analysis. Surfzone hydrodynamics is described by coupling depth and wave averaged conservation of mass and momentum with the wave-energy and phase equations, including roller dynamics. A simplified sediment transport formulat...
Article
Full-text available
We review the status of current sea-level observing systems with a focus on the coastal zone. Tide gauges are the major source of coastal sea-level observations monitoring most of the world coastlines, although with limited extent in Africa and part of South America. The longest tide gauge records, however, are unevenly distributed and mostly conce...
Article
Full-text available
We develop a process-based model to simulate the geomorphodynamic evolution of tidal channels, considering hydrodynamics, flow-induced bank erosion, gravity-induced bank collapse, and sediment dynamics. A stress-deformation analysis and the Mohr-Coulomb criterion, calibrated through previous laboratory experiments, are included in a model simulatin...
Chapter
Poorly constrained uncertainties limit the prediction of medium to long-term regional sediment budgets and morphological change, and thus hinder coastal management decision-making. We present a multi-disciplinary approach that aims to address this challenge and is implemented in the BLUEcoast project. The approach brings together scientists and coa...
Article
We performed a series of laboratory experiments to study the growth and development of wave-generated ripples under constant and varying conditions. There are two aspects of our study. First, under time varying wave conditions, we measure the rate of ripple adjustment and the equilibrium mean ripple wavelength before and after the change in forcing...
Article
Accurate simulations and predictions of urban expansion are critical to manage urbanization and explicitly address the spatiotemporal trends and distributions of urban expansion. Cellular Automata integrated Markov Chain (CA-MC) is one of the most frequently used models for this purpose. However, the urban suitability index (USI) map produced from...
Article
Full-text available
p>The process of completing and communicating rigorous, high-impact science depends heavily on obtaining quality peer review prior to publication. As AGU journals strive continually to publish excellent work, we recognize the demand that this places on reviewers' time, especially as most of us seem to receive ever-increasing numbers of requests to...