Michael Fettweis

• PhD in Science, KULeuven
• Researcher at Institute of Natural Sciences

Suspended particulate matter (SPM) is an indispensable component of water environments. Its fate and transport involve various physical and biogeochemical cycles. This paper provides a comprehensive review of SPM dynamics by integrating insights from biogeochemical processes, spatiotemporal observation techniques, and numerical modeling approaches....

Established in 2020, the EuroGOOS Fixed Platforms Task Team aims at developping Europe’s Fixed Platform network and assist in the standardisation of operations by sharing best practices, also in keeping with other relevant programmes at global level (such as EMSO. OOI, ONC, IMOS, DONET). This contribution presents an overview of the EuroGOOS Fixed...

A dynamic two-dimensional depth-averaged (2DH) parameterization for flocculation of cohesive sediments is proposed based on the kinetic model by Winterwerp (J Hydraul Res 36:309–326, 1998). The aim is to achieve a realistic representation of the suspended sediment field by accounting for flocculation, also taking into consideration its dependence o...

The high temporal and spatial variability of tidal dominated coastal areas poses a challenge for characterising water quality. Water quality monitoring relies often on information collected by water sampling from a vessel or by satellites, and covers limited time periods and therefore limited tidal and meteorological conditions. To assess the loss...

Biofilm-coated microplastics are omnipresent in aquatic environments, carrying different organic matter (OM) that in turn influences the flocculation and settling of microplastic aggregates. In this study, the effects of chitosan, guar gum, humic acid, and xanthan gum on the flocculation of anthropogenic microplastics are examined under controlled...

Plain Language Summary The transportation of fine‐grained suspended sediments in estuaries and coastal environments is a factor in many engineering and environmental issues (e.g., siltation, dredging, bed morphology, and water quality). One important characteristic that affects the transport and fate of cohesive sediment particles is flocculation,...

Interplays between microalgae and clay minerals enhance biologically mediated flocculation, thereby affecting the sedimentation and transportation of suspended particulate matter (SPM) in water and benthic environments. This interaction forms larger flocs with a higher settling velocity and enhances SPM sinking. The aim of this study was to investi...

Flocculation is a key process for controlling the fate and transport of suspended particulate matter (SPM) in water environments and has received considerable attention in the field of water science (e.g., oceanography, limnology, and hydrology), remaining an active area of research. The research on flocculation has been conducted to elucidate the...

The seasonal variation in concentration of transparent exopolymer particles (TEPs), particulate organic carbon (POC) and particulate organic nitrogen (PON) were investigated together with floc size and the concentration of suspended particulate matter (SPM) along the cross‐shore gradient, from the high turbid nearshore toward the low‐turbid offshor...

The purpose of the study was to measure in situ the background suspended particulate matter concentration (SPMC) in the DISCOL area (SE Pacific) and its increase due to mechanical mobilization of the seabed. The disturbance experiment imitated future manganese nodule exploitations and was designed to measure the sediment plume generated by such act...

The quasi-Monte Carlo (QMC) method was enhanced to solve the population balance model (PBM) including aggregation and fragmentation processes for simulating the temporal evolutions of characteristic sizes and floc size distributions (FSDs) of cohesive sediments. Ideal cases with analytical solutions were firstly adopted to validate this QMC model t...

To protect the marine environment more effectively, the European Union adopted the Marine Strategy Framework Directive (MSFD) in 2008, aiming to achieve the Good Environmental Status (GES) of the EU's marine waters by 2020 and to protect the resource base upon which marine-related economic and social activities depend. A major challenge in the impl...

Despite availability of a large amount of observational data and modelling studies, the mechanisms maintaining the Turbidity Maximum in the Belgian-Dutch coastal zone around the port of Zeebrugge (Belgium) are insufficiently understood. In order to better understand the dynamics of this turbidity maximum we examine the role of baroclinic (salinity...

Organic matter (OM) and suspended sediment are abundant, and interact with each other, in rivers and lakes. OM is usually adsorbed by suspended sediment and causes either particle stabilization or flocculation. In this study, the OM composition and suspended sediment flocculation potential of river water were regularly measured throughout the year...

This paper presents the mud dynamics in the harbor basin of Zeebrugge in the Southern North Sea based on an analysis of field data. Mud is typically transported into and within the harbor basin through advection of suspended particulate matter (SPM). Three important timescales have been identified. On the intratidal timescale, sediment import occur...

Measurement of suspended particulate matter concentration (SPMC) spanning large time and geographical scales have become a matter of growing importance in recent decades. At many places worldwide, complex observation platforms have been installed to capture temporal and spatial variability over scales ranging from cm (turbulent regimes) to whole ba...

The floc size distribution (FSD) is crucial to predict cohesive sediment dynamics in aquatic environments. Recently, increasing attention has been given to biofilm effects on the FSDs of suspended particles since the presence of biofilms on particle surfaces may lead to larger flocs and thus higher settling velocities. In this study, results from a...

The Floc Size Distributions (FSDs) of suspended fine-grained sediment flocs play a prime role to estimate their own fate and the transport of contaminates attached to the flocs. However, developing an efficient flocculation model that is capable of simulating continuous and multimodal FSDs is still a challenge. Recently, the population balance equa...

Suspended particulate matters (SPM) in coastal waters were investigated with an approach combining suspended particulate matter concentrations (SPMCs) measured by an optical backscatter sensor (OBS), particle size distributions measured by a laser in situ scattering transmissometer (LISST), and the fractal theory. The aim was to investigate whether...

The Floc Size Distributions (FSDs) of biomineral suspended particles are of great importance to understand the dynamics of bio-mediated Suspended Particulate Matters (SPMs). Field observations were investigated at Station MOW1 in Belgian coastal waters (southern North Sea) during two typical periods with abundant and reduced biomass. In addition, t...

Estuarine and coastal regions are often characterized by a high variability of suspended sediment concentrations in their waters, which influences dredging projects, contaminant transport, aquaculture and fisheries. Although various three-dimensional open source software are available to model the hydrodynamics of coastal water with a sediment modu...

Flocculation of suspended particulate matter (SPM) in marine and estuarine environments is a complex process that is influenced by physical, biological, and chemical mechanisms. The flocculation model of Maggi (2009) was adapted to simulate flocculation under various weather conditions and during different seasons. The adaptation incorporated the e...

The origin of recent mud deposits as well as the coastal turbidity maximum in the French-Belgian-Dutch nearshore area of the southern North Sea is still under debate in the literature. Some models favor the erosion of the Cretaceous chalk cliffs along the English Channel and subsequent NE ward directed transport, other models focus on the erosion o...

Suspended particulate matter (SPM) is abundant and essential in marine and coastal waters, and comprises a wide variety of biomineral particles, which are practically grouped into organic biomass and inorganic sediments. Such biomass and sediments interact with each other and build large biomineral aggregates via flocculation, therefore controlling...

The amount of sediments to be dredged and disposed depends to a large part on the suspended particulate matter (SPM) concentration. Tidal, meteorological, climatological, and seasonal forcings have an influence on the horizontal and vertical distribution of the SPM in the water column and on the bed and control the inflow of fine-grained sediments...

The Taiwan Strait (TS), situated between Taiwan and China, is shallow, relatively turbid, and characterized by strong tidal currents and winter and summer monsoon seasons. The aim of this study was to use images from the Moderate Resolution Imaging Spectroradiometer (MODIS) on board the Aqua satellite to investigate how local sediment sources in ad...

Suspended Particulate Matter (SPM) concentration profiles of the lowest 2 m of the water column and particle size distribution at 2 m above the bed were measured in a coastal turbidity maximum area (southern North Sea) during more than 700 days between 2006 and 2013. The long-term data series of SPM concentration, floc size, and settling velocity h...

Suspended particulate matter (SPM) plumes associated with the monopile foundations of the Belgian offshore wind farm (OWF) Belwind I were acoustically profiled by means of a Doppler current profiler (ADCP). Together with the analysis of a bottom lander dataset of optical and acoustic backscatter sensors (OBSs and ADPs respectively), the spatiotempo...

Overview chapter on the geology and morphosedimentary dynamics of the Flemish coast and Belgian part of the North Sea

Bimodal flocculation describes the particle/floc aggregation and breakage process in which dense microflocs and floppy macroflocs change their relative mass fraction and develop a bimodal floc size distribution (FSD). Such flocculation occurs due to the primary and secondary binding mechanisms of fine-grained cohesive sediments in a coastal zone. T...

Multimodal particle size distributions (PSDs) of fine-grained cohesive sediments are common in marine and coastal environments. The curve-fitting software in this study decomposed such multimodal PSDs into subordinate lognormal PSDs. Four modal peaks, consisting of four-level ordered structures of primary particles, flocculi, microflocs, and macrof...

The suspended particulate matter (SPM) concentration in the high turbidity zones of the southern North Sea is inversely correlated with chlorophyll (Chl) concentration. During winter SPM concentration is high and Chl concentration low and vice versa during summer. This seasonality has often been associated with the seasonal pattern in wind forcing....

Images from the Moderate Resolution Imaging Spectroradiometer (MODIS) satellite have been used to investigate the meteorological and climate induced variability of suspended particulate matter (SPM) concentration in the North Sea. The meteorology has been characterized by the 11 weather types deduced from a refined system of Lamb's classification o...

Divalent cations have been reported to develop bridges between anionic polyelectrolytes and negatively-charged colloidal particles, thereby enhancing particle flocculation. However, results from this study of kaolinite suspensions dosed with various anionic polyacrylamides (PAMs) reveal that Ca(2+) and Mg(2+) can lead to colloid stabilization under...

Suspended particulate matter (SPM) concentration and particle size distribution (PSD) were assessed in a coastal turbidity maximum area (southern North Sea) during a composite period of 37 days in January–April 2008. PSDs were measured with a LISST 100X and classified using entropy analysis in terms of subtidal alongshore flow. The PSDs during tide...

Particle size distributions (PSDs) of suspended particulate matters in a coastal zone are lognormal and multimodal in general. The multimodal PSD, which is caused by the mixing of multiple particle and aggregate size groups under flocculation and erosion/resuspension, is a record of the particle and aggregate dynamics in a coastal zone. Curve-fitti...

To counter the degradation of marine ecosystems, a variety of legislative measurements are being developed, mainly under the umbrella of the Marine Strategy Framework Directive (MSFD). The policy behind this is to ensure that human activities are performed in a sustainable way, which means that the impact of all human activities on the marine syste...

Concerns about human-induced degradation of marine ecosystems are presently being translated into European Directives aimed at a restoration of healthier seas. However, anthropogenic alterations are ancient and data on the pristine ecosystem are lacking, making the evaluation of their cumulative effects in the long run challenging. In the Belgian a...

The effect of hydro-meteorological forcings (tidal and wind-induced flows) on the transport of suspended particulate matter (SPM), on the formation of high-concentrated mud suspensions and on the occurrence of sand–mud suspensions has been studied using long-term multi-parametric observations. Data have been collected in a coastal turbidity maximum...

Large sets of suspended particulate matter (SPM) concentration data from in situ and remote sensing (moderate resolution imaging spectroradiometer, MODIS) samplings in the Belgian nearshore area (southern North Sea) are combined in order to evaluate their heterogeneity and the sampling techniques. In situ SPM concentration measurements are from a v...

poster abstract

The impact of continuous disposal of fine-grained sediments from maintenance dredging works on the suspended particulate matter concentration in a shallow nearshore turbidity maximum was investigated during dredging experiment (port of Zeebrugge, southern North Sea). Before, during and after the experiment monitoring of SPM concentration using OBS...

poster abstract

Multi-sensor tripod measurements in the high-turbidity area of the Belgian nearshore zone (southern North Sea) allowed investigating storm effects on near bed suspended particulate matter (SPM) concentrations. The data have shown that during or after a storm the SPM concentration increases significantly and that high concentrated mud suspensions (H...

In recent years, the exploitation of marine aggregates is increasing. As an example, on the Belgian continental shelf, one particular sandbank (the Kwinte Bank) is exploited extensively; this has led to the creation of a 5 m deep depression along its central part. In the present contribution, the influence of these bathymetric changes, on erosion a...

Long-term changes in the cohesive sediment distribution of the Belgian—Dutch nearshore zone (southern North Sea) are related to human activities (port construction, deepening of navigation channels, disposal of dredged sediments) and to natural variability, due to tides and meteorological effects. Results are based on the combined analyses of recen...

Direct or indirect measurements of excess density and settling velocity are inherently associated with uncertainties (errors) due to a lack of accuracy of the measuring instruments, inadequate precision of the observations, and the statistical nature of the variables (floc size, primary particle size and primary particle density). When using observ...

A study is presented where satellite images (SeaWiFS), in situ measurements (tidal cycle and snapshot) and a 2D hydrodynamic numerical model have been combined to calculate the long term SPM (Suspended Particulate Matter) transport through the Dover Strait and in the southern North Sea. The total amount of SPM supplied to the North Sea through the...

Sustainable management of the Belgian exclusive economic zone (EEZ) has become important increasingly. This is due mainly to higher exploitation demands of marine aggregates, but also the dredging industry imposes high stresses on the seafloor. To anticipate on future developments, including the implantation of windmill farms, efficient evaluation...

Measurements of aggregate size, suspended particulate matter (SPM) concentration and current velocity have been carried out in the Belgian coastal zone (southern North Sea). Two stations were situated in the coastal turbidity maximum zone; another station was located more offshore at the edge of this turbidity maximum. The data have been collected...

The benthic (zoobenthos and microphytobenthos) and physical characteristics of intertidal sediments were studied in April and September 1997 on 10 locations, differing in elevation and exposure to tidal currents, situated on three mudflats in the mesohaline part of the Schelde estuary. Sediment characteristics were spatially and temporally relative...

Suspended particulate matter concentration (SPM) maps at water-surface were retrieved from 172 SeaWiFS images using the MUMM turbid water extension to the SEADAS4.4 software and a regionally calibrated hydro-optical model. Examination of surface-SPM maps and the depth-averaged SPM derived from a 2D-hydrodynamic and sediment transport model over the...

ISSN 0749-0208. The Belgian coastal zone is shallow, well mixed and has a high hydrodynamic energy. In the coastal zone a turbidity maximum occurs, which is responsible for high dredging amounts. Every year about 10x10 ton dry matter (TDM) is dredged for the maintenance of the harbours and the navigation channels. After dumping the matter is transp...

The suspended sediment processes and the mudfields found in the Belgian/Dutch coastal area (Southern North Sea) are discussed by presenting an integrated data-modelling approach of the suspended sediment transport along the Belgian–Dutch coast, using a fine-grid coupled 2D hydrodynamic and sediment transport model and existing field and literature...

Nood aan evaluatiemiddelen voor de opvolging van kustsystemen. In: V. Van Lancker et al. (eds.). Colloquium 'Kustzonebeheer vanuit geo-ecologische en economische invalshoek'. Oostende (B), 16-17 mei 2002. Genootschap van Gentse Geologen (GGG)–Vlaams Instituut van de Zee (VLIZ). VLIZ Special Publication 10 : Oostende, Belgium.

The cohesive sediment transport in tidal rivers and estuaries is determined by the river discharge, the morphology, the salinity, temperature and particulate gradients, the deposition and erosion processes, the effective settling velocity of mud particles and by the physico-chemical and biological processes. The combination of these processes ensur...

This paper presents the results of the II Tidal Flow Forum experiment of the English Channel and the southern North Sea. The model applies the FADI (falsified alternating direction implicit) scheme and uses the data base of the Tidal Flow Forum. Discrepancies between the model results and the distributed field data of 11 tide stations and 8 tidal c...

A two-dimensional depth-averaged numerical model for tidal flow computa tions is presented. The model applies the finite difference method together with a falsified alternat.ing direction implicit. scheme to solve the shallow water equations. The possibility of using the technique of grid refinement has been included in the model. A North-West Euro...

The fall velocity (w s) of flocs is a crucial parameter in cohesive sediment transport modelling and varies between approximately 0.01 and 10 mm/s. The variation of fall velocity during a tidal cycle or a neap-spring cycle is important in areas with high tidal energy. Fall velocity can be directly measured using e.g. video cameras or a LISST-ST, bu...

Particle Size Distributions (PSDs) of suspended particulate matter are log-normal and multi-modal in general. The log-normality describes a more or less skewed distribution toward small size particles, and the multimodality describes a distribution consisting of multiple peaks. In a coastal environment suspended sediments consist often of flocs. Th...

The biological population dynamics (e.g. algae bloom) have been concerns of biologists and ecologists, whereas the sediment dynamics have been interest of geologists and hydraulic engineers, in a marine and coastal environment. The biological and mineralogical populations seem separate in different fields of study. Recent studies however have found...

Suspended Particulate Matter (SPM) transport has a major influence on coastal ecosystems and on the siltation of ports and naviagtion channels. The distribution of SPM is also affected by human activities such as port development, dredging and dumping and aggregate extraction. These activities have further major impacts on the environment, due to s...

A 2.5D baroclinic ocean model is presented to simulate the upwelling processes along the continental slope and along a marginal ice edge. Two different cases are considered, a flat bottom and a shelf/ocean one. The water is forced by a wind blowing parallel to the coast in upwelling favorable direction and by density gradients due to melting of ice...