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The Dutch climate is changing; winters are becoming wetter and summers are becoming drier. How can water management at regional level respond to the increasing drought in the growing season? Model calculations were used to study the effect of water retention measures at regional level on agriculture and nature in the eastern sandy area of Friesland. In addition, the effectiveness of water retention measures was evaluated in field experiments on seven dairy farms. Model results showed that in the current climate, the increase in wet damage was larger than the decrease in drought damage following regional water retention measures, resulting in a slight net increase in total damage. For the future Dutch climate (Gh-2050), both wet and drought damage increased compared to the current reference situation, with drought damage increasing relatively more than wet damage. In contrast to measures on a regional scale, water measures taken on farm scale in field experiments reduced drought damage to a larger extent than the increase in wet damage. Farm-scale measures therefore appear to be more effective than regional measures. Results also showed that the more farmers implement water retention measures, the better they will succeed in structurally raising the low groundwater level in the summer. It is expected that a large-scale approach to water conservation will pay off, if its implementation is locally tailored. The low-lying peat and bog parts (watershed areas) are the limiting factor for water retention due to the extra wetting occurring in this areas. For these soils it is important to combine different tasks: water storage, stream restoration, nature development, water storage and lower greenhouse gas emissions by reducing peat oxidation. Robust and future-oriented water management requires choices regarding the low parts of the sandy area., Het Nederlandse klimaat verandert; de winters worden natter en de zomers worden droger. Hoe kan met regionaal waterbeheer worden ingespeeld op de toenemende droogte in het groeiseizoen? Aan de hand van modelberekeningen is onderzocht wat het effect is van watervasthoudende maatregelen op gebiedsniveau, op landbouw en natuur in het oostelijke zandgebied van Friesland. Daarnaast is aan de hand van praktijkproeven de effectiviteit van watervasthoudende maatregelen onderzocht op zeven agrarische bedrijven. Uit het modelonderzoek bleek dat door het nemen van maatregelen op regionale schaal bij het huidige klimaat voor landbouw de natschade meer toenam dan de droogteschade afnam, waardoor netto de totale schade licht steeg. Bij het toekomstig klimaat (Gh-2050) namen zonder maatregelen zowel de nat- als droogteschade toe ten opzichte van de huidige referentiesituatie, waarbij de droogteschade relatief meer toenam dan de natschade. Bij watermaatregelen op lokale schaal (praktijkproeven) nam, in tegenstelling tot maatregelen op regionale schaal, de droogteschade meer af dan de natschade toenam. Bedrijfsspecifieke maatregelen lijken daarmee doelgerichter dan algemene, regionale maatregelen. Daarbij toont het onderzoek aan dat hoe meer agrariërs watervasthoudende maatregelen uitvoeren, hoe beter men erin slaagt om de lage grondwaterstand in de zomer structureel te verhogen. Verwacht wordt dat een grootschalige aanpak van water vasthouden loont, indien dit lokaal op basis van maatwerk wordt uitgevoerd. Voor water vasthouden zijn de laag gelegen veen- en moerige gronden (veelal beekdalen) de beperkende factor door de extra vernatting die hier optreedt. Voor deze bodems is het belangrijk om verschillende opgaven te combineren: waterberging, beekherstel, natuurontwikkeling, waterberging en lagere uitstoot broeikasgassen door vermindering veenafbraak. Een robuust en toekomstgericht waterbeheer vraagt om keuzes met betrekking tot deze lage delen van het zandgebied.

Fibres, as abundant in agricultural by-products, exhibit a large range of physicochemical properties that can influence digestive processes such as digesta mean retention time (MRT), thereby affecting nutrient digestion kinetics. In this study, we investigated the effects of particle size of insoluble fibres, and gelation of soluble fibres on MRT of liquids, fine solids, and fibrous particles in the different segments of the gastrointestinal tract (GIT) of pigs. Twenty-four boars (51.6 ± 4.90 kg) were allocated to four diets; two diets contained 15% wheat straw, either coarsely chopped or finely ground (1-mm screen), two diets contained 27% wheat bran without or with the addition of 10% low-methylated pectin. After 14 days of adaptation to the diet, a total collection of faeces was performed to determine the total tract digestibility of nutrients. Thereafter, pigs were fed diets supplemented with tracers for at least 5 days and dissected following a frequent feeding procedure to approach steady-state passage of digesta. The MRT of liquids (Co-EDTA), fine solids (TiO2), and fibrous particles (Chromium-mordanted fibres) in the different segments of the GIT were quantified. In the stomach, particle size reduction of straw decreased the MRT of fine solids by 02:39 h, and fibrous particles by 07:21 h (P < 0.10). Pectin addition to the wheat bran diet reduced the MRT of fine solids by 03:09 h, and fibrous particles by 07:10 h (P < 0.10), but not of liquids, resulting in less separation between digesta phases in the stomach compared with the bran diet (P < 0.05). In the mid−small intestine (SI), pectin addition reduced the MRT of fibrous particles and the separation between fibrous particles and fine solids. No further effects of particle size reduction of straw nor pectin addition on MRT and digestibility of starch, nitrogen, or fat were observed in the SI. In the large intestine (LI), particle size reduction of straw reduced separation between fibrous particles and fine

Quantitative predictions of marine and aeolian sediment transport in the nearshore–beach–dune system are important for designing Nature-Based Solutions (NBS) in coastal environments. To quantify the impact of the marine-aeolian interactions on shaping NBS, we present a framework coupling three existing process-based models: Delft3D Flexible Mesh, SWAN and AeoLiS. This framework facilitates the continuous exchange of bed levels, water levels and wave properties between numerical models focussing on the aeolian and marine domain. The coupled model is used to simulate the morphodynamic evolution of the Sand Engine mega-nourishment. Results display good agreement with the observed aeolian and marine volumetric developments, showing similar marine-driven erosion from the main peninsula and aeolian-driven infilling of the dune lake. To estimate the magnitude of the interactions between aeolian and marine processes, a comparison between the simulated morphological development by the coupled and stand-alone models was made. This comparison shows that aeolian sediment transport to the foredune, i.e. 214,000 m3 over 5 years, extracts sediment from the marine domain. As a result, the alongshore redistribution of sediment from the main peninsula by marine-driven processes decreased by 70,000 m3, representing 1.7% of the total marine-driven dispersion. From the aeolian perspective, marine-driven deposition and erosion reshape the cross-shore profile, controlling the supply-limited aeolian sediment transport and the magnitude of sediment deposition in the foredunes. In the region with persistent accretion along the Sand Engine's southern flank, a higher than average foredune deposition was predicted due to morphological development of the region where sediment is picked up by aeolian transport. Including these marine processes in the coupled model resulted in an increase of 1.3% in foredune growth in year 1 and up to 6.7% in year 5 along this accretive se, Hydraulic Engineering, Coastal Engineering

As part of the transition to circular agriculture and to reduce food-feed competition for arable land, the inclusion of coproducts in livestock feed is expected to increase. Pellet manufacturing allows for improving the handling properties of livestock feed, but the effect of fibrous coproducts on the process is poorly understood. Inclusion of coproducts is considered to affect the physicochemical characteristics of a feed mash, and subsequently pellet manufacturing. To understand how coproducts can effectively be incorporated in pellet manufacturing, we investigated the effect of the inclusion of 300 g/kg of various fibrous coproducts, differing in fibrous composition, in feed mash containing 700 g/kg of basic mash, containing soybean meal, maize and soy oil, on mash physicochemical properties and pellet manufacturing. Treatment mashes were prepared in singleton, steam-conditioned and compacted using a ring-die pelletizer. Physical pellet quality, production capacity, and energy consumption of the pellet press were evaluated per treatment mash. Mash physicochemical properties were evaluated by determining hydration properties (i.e. water binding capacity and sorption analyses) and thermomechanical properties (i.e. phase transition and capillary rheometric analysis). Pellet durability varied among treatments (15.8–91.1 %), as did total energy costs of compaction (28.0–38.7 kWh/tonne). Principal component analysis indicated that higher levels of insoluble fibre in a feed mash associated with increased shear stress during capillary rheometric analysis. Combinedly these parameters reduced production capacity (R2 = 0.25; P = 0.046) and increased required energy consumption by the pellet press (R2 = 0.30; P = 0.03), but could only limitedly explain variation among treatments. In conclusion, the inclusion of coproducts with higher or lower levels of fibre did not consistently affect physical pellet quality. The overall low pellet durability (<90%) of all treatments, howev

Nearshore hydro- and morphodynamic data were collected during a field experiment under calm conditions, moderate conditions, and storm conditions with dune erosion in the collision regime. The experiment was conducted on the Sand Engine near Kijkduin, the Netherlands, from October 18, 2021, to January 7, 2022. Two artificial unvegetated dunes were constructed just above the high water line to measure storm erosion and dune impacts from higher water levels and waves. During the experiment, three storms occurred that resulted in significant erosion of both dunes. The collected hydrodynamic data include pressure sensor and velocimeter data along two cross-shore transects. The collected morphodynamic data include bathymetry and topography surveys, optical backscatter sensor data in the inner surf zone, and a continuous cross-shore line-scanning lidar data set of the dune face. This comprehensive data set can be used to (1) study relevant nearshore hydrodynamic and morphodynamic processes that occur during calm conditions, moderate conditions, and storm conditions with dune erosion in the collision regime, and (2) validate existing dune erosion models., Coastal Engineering, Environmental Fluid Mechanics

A field experiment to study dune erosion was conducted on the Sand Engine near Kijkduin, the Netherlands, from November 7th 2021 to January 7th 2022. Two artificial unvegetated dunes were constructed near the high water line, and experienced significant erosion through avalanching during three storms. This paper aims to identify what drives dune erosion through avalanching by using the collected data and equilibrium theory. Results suggest that the cumulative volume eroded through avalanching during a single high water is positively correlated with the profile mismatch between the pre-storm profile and a ‘storm equilibrium profile’, described by a 2/3rd power law, an empirical coefficient A, and the total water level. This mismatch is quantified by calculating the area integral of the profile that is acquired when the upper 35 m of the pre-storm profile is subtracted from the upper 35 m of the equilibrium profile. Avalanching commences when this mismatch becomes larger than approximately 0, after which 1 m3/m of sediment erodes from the dune face for every 3 m3/m mismatch. In addition, during one event avalanching occurred even though the elevation of the total water level did not exceed the initial elevation of the dune toe. This implies that a total water level that exceeds the initial elevation of the dune toe is not a requisite for avalanching and a collision regime to occur, which contradicts conventional definitions of dune erosion regimes. These results have implications on risk assessment of storm conditions on dune erosion., Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public., Coastal Engineering, Environmental Fluid Mechanics

Storm conditions can lead to excessive dune erosion with potential floods as a consequence. Barrier islands and low-lying countries protected by dunes are especially vulnerable to dune erosion. To properly assess the risks these areas face, a clear understanding of the physical processes during dune erosion is required. One of such processes is the effect of wave obliquity on sediment transport in the surf zone. Classic dune erosion models assume that dune erosion volumes decrease under oblique wave attack, because the time-averaged cross-shore undertow decreases in magnitude and with that offshore directed sediment transport decreases (Steetzel, 1993). More recent process-based erosion models predict an increase in erosion quantities, because the generated longshore currents increase surf zone sediment concentrations, and with that offshore directed sediment transport increases (Den Heijer, 2013). The main objective of this study is to analyse the effect of wave obliquity on dune erosion through a field experiment, by quantifying the effect of the decreasing undertow but increasing alongshore current on sediment concentrations in the surf zone., Coastal Engineering, Environmental Fluid Mechanics, Civil Engineering & Geosciences

Infragravity (IG) waves are key drivers for coastal erosion and thus need to be properly included in process-based modelling of coastal hazards. Uncertainties remain regarding the offshore boundary conditions for these long waves. Typically, only bound IG waves are included at the boundary, which means that the possible contribution of free IG waves, such as those radiated from distant coastlines, is neglected. Recent studies however suggest that incoming free IG waves could be significant, particularly in semi-enclosed basins such as the North Sea where they could contribute to coastal hazards (e.g., Reniers et al., 2021, Rijnsdorp et al. 2021). The objective of this work is to improve the understanding of the incoming IG wave field along the Dutch coast. We will quantify how bound and free IG waves develop in intermediate water depths and assess in which conditions (onshore directed) free IG waves become significant., Environmental Fluid Mechanics, Coastal Engineering

1. Green space matters for mental health but is under constant pressure in an increasingly urbanising world. Often there is little space available in cities for green areas, so it is vital to optimise the design and usage of these available green spaces. To achieve this, experts in planning, design and nature conservation need to know which types and characteristics of green spaces are most beneficial for residents' mental health.2. A scoping review of studies that compare different green space types and characteristics on mental health was conducted. A total of 215 (experimental, observational and qualitative) papers were included in the scoping review.3. This review highlights a high level of heterogeneity in study design, geographical locations, mental health outcomes and green space measures. Few of the included studies were specifically designed to enable direct comparisons between green space types and characteristics (e.g. between parks and forests). The included studies have predominantly experimental research designs looking at the effects of short-term exposure to green space on short-term mental health outcomes (e.g. affect and physiological stress). More studies enabled only indirect comparisons, either within the same study or between different studies.4. Analysis of the direction of the mental health outcomes (positive, neutral, negative) from exposure to various types and characteristics of green space found positive (i.e. beneficial) effects across all green space types. However, green space characteristics did appear to render more diverse effects on mental health, which is especially the case for vegetation characteristics (e.g. higher vegetation density can be negative for mental health).5. The scoping review reveals gaps in the present evidence base, with a specific need for more studies directly comparing green space types and characteristics within the same study. Proposed future research directions include the use of longitudinal research desi

Fractionation of digesta, as occurs during gastrointestinal transit in chickens, complicates accurate measurements of ileal digestibility using tracers. Dual-tracer methods using separate tracers for solid and fluid digesta phases may improve the accuracy of digestibility measurements when assumptions of the single tracer method are violated. The aim of the present study was to compare the apparent ileal digestibility (AID) of nutrients calculated with single- and dual-tracer methods in chickens fed diets varying in particle size, anticipating digesta phase separation in the proximal gastrointestinal tract. A total of 112 Dekalb White (BW: 1.53 ± 0.107 kg) and 112 Bovans Black (BW: 1.79 ± 0.127 kg) 29-week-old laying hens were distributed over 32 pens (seven birds/pen). Within breed, pens were randomly assigned to one of two experimental diets (coarse vs fine oat hulls; n = 8 replicate pens per diet/breed combination). Diets were supplemented with TiO2 (3 g/kg) and Co-EDTA (2 g/kg). On days 34, 35, or 36, birds were euthanised and digesta from the ileum was collected for tracer and nutrient analyses. Apparent ileal digestibility was subsequently calculated by single- and dual-tracer methods. Although coarse oat hulls were hypothesised to increase the fractionation of solid and fluid digesta phases, no breed or diet × method interactions were found. Using a single tracer method based on TiO2, AID of nitrogen (N) was overestimated by 3%-units (P < 0.01) compared with the dual-tracer method, whereas AID estimates of DM, starch, fat, and non-starch polysaccharides did not differ (P > 0.09) and precision of all AID estimates was improved. In conclusion, these results show that although from a conceptual perspective, dual-tracer methods are presumed to better account for the variation in flow behaviour of different digesta phases, AID estimates obtained by the commonly used single tracer method using solid-phase tracer TiO2 were more precise and only marginally differed f

Dietary fibres impact multiple digestive processes, and insights into the effects of various types of fibre on digesta retention time are required to optimise current feed formulation systems. Therefore, the objective of this study was to apply a dynamic modelling approach to generate estimates for the retention time of solid and liquid digesta in broilers fed different fibre sources. A maize-wheat-soybean meal control diet was compared against three diets in which wheat was partially substituted with oat hulls, rice husks, or sugar beet pulp (3% w/w). Non-starch polysaccharide (NSP) digestibility was evaluated in broilers between 23 and 25 days of age (n = 60 birds/treatment) using titanium dioxide (TiO2, 0.5 g/kg) as a marker, after feeding the experimental diets for 21 days. Digesta mean retention time (MRT) was measured in another 108 birds at 30 days of age by the administration of an oral pulse dose of chromium sesquioxide (Cr2O3) as solid marker and Cobalt-EDTA as liquid marker, and subsequent measurement of marker recovery in compartments of the digestive tract (n = 2 or 3 replicate birds/time point/treatment). Marker recovery models to estimate fractional passage rates for solid and liquid digesta in crop, gizzard, small intestine, and caeca compartments of the gastrointestinal tract were developed to predict MRT of solid and liquid digesta for each dietary treatment. The models were composed of a series of first-order differential equations, representing the variation of marker concentration in a compartment over time. Estimated MRT of solid and liquid digesta in the gizzard varied from 20 min for oat hulls and 34 min for rice husks diets to 14 min for sugar beet pulp and 12 min for control diets. In the caeca, liquid MRT was decreased compared to the control diet (989 min) for the sugar beet pulp diet (516 min), while it was increased for both the oat hulls and rice husks diets (≈1 500 min). Overall, these estimates are greater than those previously repor

1. Green space matters for mental health but is under constant pressure in an increasingly urbanising world. Often there is little space available in cities for green areas, so it is vital to optimise the design and usage of these available green spaces. To achieve this, experts in planning, design and nature conservation need to know which types and characteristics of green spaces are most beneficial for residents' mental health. 2. A scoping review of studies that compare different green space types and characteristics on mental health was conducted. A total of 215 (experimental, observational and qualitative) papers were included in the scoping review. 3. This review highlights a high level of heterogeneity in study design, geographical locations, mental health outcomes and green space measures. Few of the included studies were specifically designed to enable direct comparisons between green space types and characteristics (e.g. between parks and forests). The included studies have predominantly experimental research designs looking at the effects of short-term exposure to green space on short-term mental health outcomes (e.g. affect and physiological stress). More studies enabled only indirect comparisons, either within the same study or between different studies. 4. Analysis of the direction of the mental health outcomes (positive, neutral, negative) from exposure to various types and characteristics of green space found positive (i.e. beneficial) effects across all green space types. However, green space characteristics did appear to render more diverse effects on mental health, which is especially the case for vegetation characteristics (e.g. higher vegetation density can be negative for mental health). 5. The scoping review reveals gaps in the present evidence base, with a specific need for more studies directly comparing green space types and characteristics within the same study. Proposed future research directions include the use of longitudinal research

Dune erosion during storm surges can lead to excessive damage to the dune system with devastating floods as a potential consequence. A risk assessment of areas protected by dunes can be facilitated by an understanding and description of the physical processes that take place. Field measurements, knowledge of underlying processes and numerical modelling have developed with time, which enabled a more comprehensive description and new predictive techniques. This review concerns dune erosion in the collision regime, and summarises relevant observations, describes underlying processes and explains existing models predicting dune erosion. Observations of dune erosion consist of field observations, laboratory experiments and manipulative field campaigns. The underlying physical processes that contribute to dune erosion are divided into processes that contribute to sediment transport due to hydrodynamic forcing, which occurs in the surf and swash zone, and sediment transport due to avalanching, which occurs in the swash zone, on the dune face and on the dune crest. The existing dune erosion models that are discussed here contain (empirical) equilibrium profile models and process-based models, which can both be a valuable tool for the risk assessment of storm surges. However, model uncertainties still remain, as specific processes are not yet fully understood and described. Examples are the influences of wave obliquity, sediment grain size, and vegetation on the dune face. By improving our knowledge through research and reducing these uncertainties, we can further improve our predictive models. This could eventually lead to more accurate predictions, more complete risk assessments, and sandy coastlines which are more resilient to excessive dune erosion and possible floods., Coastal Engineering, Environmental Fluid Mechanics, Hydraulic Engineering

A model that simulates surface moisture content on sandy beaches for aeolian transport applications is developed and integrated into the aeolian transport model AeoLiS. The moisture content of a thin surface layer (≈2 mm thickness) is computed as a function of wave runup, precipitation, evaporation, percolation, and capillary rise from the groundwater table. The groundwater table is simulated using a modified Boussinesq equation accounting for the overheight due to wave runup. The surface moisture due to capillary rise is simulated with an experimentally determined soil water retention (SWR) curve of the “van Genuchten” type. Hysteresis is accounted for by differentiating between SWR curves for drying and wetting conditions. The model is tested against a data set of 221 point observations of surface moisture from Noordwijk beach in the Netherlands. The measured surface moisture within the study area displays large spatial and temporal variability. The model results display an expected cross-shore gradient of moisture content, but also a large scatter when compared to the data. The scatter may partly be explained by local variability of hydraulic properties that are not accounted for within the model. Despite the scatter, the proposed surface moisture model is a starting point to integrate the transport limiting effect of surface moisture into meso-scale aeolian transport models. To facilitate model setup and the use of this surface moisture model, the soil water retention data from 10 beaches with variable grain size characteristics are provided in this study. Future studies may focus on additional model validation against data sets with variable meteorological conditions and simultaneous moisture and aeolian transport observations., Coastal Engineering

Grain size affects the rates of aeolian sediment transport on beaches. Sediment in coastal environments typically consists of multiple grain-size fractions and exhibits spatiotemporal variations. Still, conceptual and numerical aeolian transport models are simplified and often only include a single fraction that is constant over the model domain. It is unclear to what extent this simplification is valid and if the inclusion of multi-fraction transport and spatial grain-size variations affects aeolian sediment transport simulations and predictions of coastal dune development. This study applies the numerical aeolian sediment transport model AeoLiS to compare single-fraction to multi-fraction approaches for a range of grain-size distributions and spatial grain-size scenarios. The results show that on timescales of days to years, single-fraction simulations with the median grain size, D50, often give similar results to multi-fraction simulations, provided the wind is able to mobilize all fractions within that time frame. On these timescales, vertical variability in grain size has a limited effect on total transport rates, but it does influence the simulation results on minute timescales. Horizontal grain-size variability influences both the total transport rates and the downwind bed grain-size composition. The results provide new insights into the influence of beach sediment composition and spatial variability on total transport rates toward the dunes. The findings of this study can guide the implementation of grain-size variability in numerical aeolian sediment transport models., Coastal Engineering, Environmental Fluid Mechanics

1. Green space matters for mental health but is under constant pressure in an increasingly urbanising world. Often there is little space available in cities for green areas, so it is vital to optimise the design and usage of these available green spaces. To achieve this, experts in planning, design and nature conservation need to know which types and characteristics of green spaces are most beneficial for residents' mental health. 2. A scoping review of studies that compare different green space types and characteristics on mental health was conducted. A total of 215 (experimental, observational and qualitative) papers were included in the scoping review. 3. This review highlights a high level of heterogeneity in study design, geographical locations, mental health outcomes and green space measures. Few of the included studies were specifically designed to enable direct comparisons between green space types and characteristics (e.g. between parks and forests). The included studies have predominantly experimental research designs looking at the effects of short-term exposure to green space on short-term mental health out-comes (e.g. affect and physiological stress). More studies enabled only indirect comparisons, either within the same study or between different studies. 4. Analysis of the direction of the mental health outcomes (positive, neutral, negative) from exposure to various types and characteristics of green space found positive (i.e. beneficial) effects across all green space types. However, green space characteristics did appear to render more diverse effects on mental health, which is especially the case for vegetation characteristics (e.g. higher vegetation density can be negative for mental health). 5. The scoping review reveals gaps in the present evidence base, with a specific need for more studies directly comparing green space types and characteristics within the same study. Proposed future research directions include the use of longitudinal research

Due to the growing demand for food, the availability of starch-rich ingredients (e.g. feed grade cereals), whose areal can be used for producing food, is expect to decline. In turn, the use of co-products, from food- and biofuel industry, is expected to increase in livestock feed. However, these co-products are fibre-rich and can negatively affect pellet manufacturing, by reducing pellet quality and increasing energy costs. The thermomechanical properties of feed mashes are considered to be important for agglomeration processes, but its relation to feed composition and its role in pellet manufacturing is poorly understood. The aim of this study was to investigate the effect of fibrous co-product inclusion in feed mashes on their thermomechanical properties and subsequent effects on pellet manufacturing. Treatment mashes were formulated to contain 700 g/kg basic mash, consisting of soybean meal, maize, and soy oil, to which 0–300 g/kg palm kernel expeller, sugar beet pulp, wheat straw and isolated native maize starch were added, according to a four-component mixture design. Treatments were prepared in duplicate, conditioned using a single-shaft conditioner and compacted using a ring-die pelletizer (die hole diameter 6 mm, L/D ratio 12). Pellet quality, production capacity and gross specific mechanical energy consumption per megagram (Mg) were documented. Mash deformability was evaluated by increasing the moisture content of a mash sample to 150 g/kg, followed by compression at 10 MPa and increasing temperature by 4 °C/minute using the Phase Transition Analyzer (PTA; Wenger Manufacturing, Sabetha, KS, US). Inclusion of wheat straw significantly increased mash deformability. Inclusion of isolated native maize starch and fibrous co-products was observed to increase pellet quality in comparison to the basic mash. Mash deformability at compactor temperature was correlated with bulk density (r = −0,83; P < 0.001). Pellet compressive strength was associated with mash deform

There is no such thing as human health without a healthy planet. Forests are a central part of the planet’s ecosystems and, as such, understanding human-forest interdependence is central to achieving optimal health for all, now and for future generations. Contemporary human health challenges differ across the globe. In high-income countries, there is a dominance of non-communicable diseases that, to some extent, are related to a disconnect from, and unhealthy interactions with, forests. In other parts of the world, health is related to interactions with forests through, for example, nutrition and other services provided by forests or through infectious diseases, such as malaria, that are in turn all impacted by forest management and practices. Planetary health approaches provide a way of considering environmental protection as an inherent part of the solution to health. In this context, forests play an important role. Positive interactions with healthy forest ecosystems can contribute to various services, such as promotion of healthier lifestyles, prevention of disease and livelihoods. This chapter defines common concepts and discusses the need for systems thinking when addressing the complex and dynamic relationships between forests and human health, including the importance of acknowledging voices and knowledge from Indigenous peoples and local communities. It outlines the consequences of urbanisation and humans’ disconnect from nature as well as various theories, pathways and mechanisms that support evidence on positive health impacts of forests. Finally, it provides a framework that brings together the information provided in the remainder of the report.

There is no such thing as human health without a healthy planet. Forests are a central part of the planet’s ecosystems and, as such, understanding human-forest interdependence is central to achieving optimal health for all, now and for future generations. Contemporary human health challenges differ across the globe. In high-income countries, there is a dominance of non-communicable diseases that, to some extent, are related to a disconnect from, and unhealthy interactions with, forests. In other parts of the world, health is related to interactions with forests through, for example, nutrition and other services provided by forests or through infectious diseases, such as malaria, that are in turn all impacted by forest management and practices. Planetary health approaches provide a way of considering environmental protection as an inherent part of the solution to health. In this context, forests play an important role. Positive interactions with healthy forest ecosystems can contribute to various services, such as promotion of healthier lifestyles, prevention of disease and livelihoods. This chapter defines common concepts and discusses the need for systems thinking when addressing the complex and dynamic relationships between forests and human health, including the importance of acknowledging voices and knowledge from Indigenous peoples and local communities. It outlines the consequences of urbanisation and humans’ disconnect from nature as well as various theories, pathways and mechanisms that support evidence on positive health impacts of forests. Finally, it provides a framework that brings together the information provided in the remainder of the report.

Pellet manufacturing is a useful tool for improving the handling of livestock feed. Pellet manufacturing consists, among others, of a compaction step, which is strongly affected by feed formulation. The role of feed formulation is thought to result from the fact that feed mash physicochemical properties change depending on ingredient composition. This variation in physicochemical properties subsequently affects mash behaviour during compaction, leading to variation in both physical pellet quality and energy costs during pellet manufacturing. Methodologies that allow for the study of material behaviour at pellet manufacturing conditions are needed to investigate the effect of feed formulation on mash flow behaviour. Such methodologies, however, are currently not generally available in the field of feed manufacturing. In this short communication we aim to discuss the application of capillary rheometry as a potential method for studying feed behaviour in the die, at conditions comparable to those during pellet manufacturing. The similarity between the design of the capillary rheometer and the geometry of a ring-die compactor allows for the simulation of some of the conditions experienced by feed mash during compaction, using smaller quantities of sample materials. The observed relation between flux and pressure gradient, for feed mashes evaluated in this short communication, resembles a Herschel-Bulkley relation, indicating that the increase in pressure gradient depends non-linearly on flow rate. While individual pressure gradients provide insight in the relative energy costs of compaction, a modelling approach is recommended to simulate the behaviour of feed mash at conditions more closely approximating those during pellet manufacturing. In summary, capillary rheometry provides an option for studying feed mash behaviour at conditions approximating those in the pellet press during pellet manufacturing.

Undigested proteins that become available for the microbiota in the hindgut can be used as building blocks for bacterial cells, or can enter various catabolic pathways. Degradation via protein fermentation pathways is least preferred, as several fermentation end-products released can be toxic for the host. Directing microbial protein metabolism towards protein synthesis or degradative pathways that result in less toxic end-products, for example through nutritional interventions, is an interesting strategy for improving health. We studied variation in protein fermentation patterns, resulting from variation in substrate composition. Ileal digesta, obtained from cannulated pigs fed different protein sources, were subjected to fermentation in vitro under different conditions; (1) ileal digesta were fermented as-is, (2) ileal digesta were fermented after standardisation to a constant high C:N ratio, by addition of high fermentable carbohydrates and (3) ileal digesta samples were incubated under limiting N concentrations. Gas production was monitored as an indirect measure of microbial activity, and fermentation end-products at different points in time were analysed by gas chromatography and high resolution mass spectrometry. Using principal component analysis, we identified patterns in protein fermentation end-products and related them to the composition of ileal digesta. Protein-associated fermentation end-product concentrations of e.g. isovaleric-, isobutyric-, phenylacetic acid and p-cresol were negatively affected by the available amount of high fermentable carbohydrates combined with a high C:N ratio. The aforementioned fermentation end-products positively correlated with NH3 concentrations and negatively with short-chain fatty acid (SCFA) concentrations. Standardisation to a constant high C:N ratio changed their relationship; isovaleric-, isobutyric-, phenylacetic acid and p-cresol lost their correlation with NH3 concentrations, became positively correlated with SC

Current feed formulation and evaluation practices rely on static values for the nutritional value of feed ingredients and assume additivity. Hereby, the complex interplay among nutrients in the diet and the highly dynamic digestive processes are ignored. Nutrient digestion kinetics and diet × animal interactions should be acknowledged to improve future predictions of the nutritional value of complex diets. Therefore, an in silico nutrient-based mechanistic digestion model for growing pigs was developed: “SNAPIG” (Simulating Nutrient digestion and Absorption kinetics in PIGs). Aiming to predict the rate and extent of nutrient absorption from diets varying in ingredient composition and physicochemical properties, the model represents digestion kinetics of ingested protein, starch, fat, and non-starch polysaccharides, through passage, hydrolysis, absorption, and endogenous secretions of nutrients along the stomach, proximal small intestine, distal small intestine, and caecum + colon. Input variables are nutrient intake and the physicochemical properties (i.e. solubility, and rate and extent of degradability). Data on the rate and extent of starch and protein hydrolysis of different ingredients per digestive segment were derived from in vitro assays. Passage of digesta from the stomach was modelled as a function of feed intake level, dietary nutrient solubility and diet viscosity. Model evaluation included testing against independent data from in vivo studies on nutrient appearance in (portal) blood of growing pigs. When simulating diets varying in physicochemical properties and nutrient source, SNAPIG can explain variation in glucose absorption kinetics (postprandial time of peak, TOP: 20–100 min observed vs 25–98 min predicted), and predict variation in the extent of ileal protein and fat digestion (root mean square prediction errors (RMSPE) = 12 and 16%, disturbance error = 12 and 86%, and concordance correlation coefficient = 0.34 and 0.27). For amino acid absorptio

Herinrichting van het landelijk gebied wordt steeds vaker genoemd als de weg uit de stikstofcrisis en als oplossing voor andere ruimtelijke problemen, zoals vervuiling van grond- en oppervlaktewater, droogteschade aan huizen en natuur, verlies aan biodiversiteit en bodemorganische stof, en de uitstoot van broeikasgassen.

Sandy coasts form the interface between land and sea and their morphologies are highly dynamic. A combination of human and natural forcing results in morphologic changes affecting both nature values and coastal safety. Terrestrial laser scanning (TLS) is a technique enabling near-continuous monitoring of the changing morphology of a sandy beach-dune system with centimetre-order accuracy. In Kijkduin, The Netherlands, a laser scanner sampled one kilometre of coast at hourly intervals for about six months. This resulted in over 4,000 consecutive topographic scans of around one million points each, at decimetre-order point spacing. Analysis of the resulting dataset will offer new insights into the morphological behaviour of the beach-dune system at hourly to monthly time scales, ultimately increasing our fundamental scientific understanding of these complex geographic systems. It further provides the basis for developing novel algorithms to extract morphodynamic and geodetic information from this unique 4D spatiotemporal dataset. Finally, experiences from this TLS setup support the development of improved near-continuous 3D observation of both natural and anthropogenic scenes in general., Coastal Engineering, Optical and Laser Remote Sensing, Hydraulic Engineering

Optical satellite images of the nearshore water surface offer the possibility to invert water depths and thereby constitute the underlying bathymetry. Depth inversion techniques based on surface wave patterns can handle clear and turbid waters in a variety of global coastal environments. Common depth inversion algorithms require video from shore-based camera stations, UAVs or Xband-radars with a typical duration of minutes and at framerates of 1–2 fps to find relevant wave frequencies. These requirements are often not met by satellite imagery. In this paper, satellite imagery is augmented from a sequence of 12 images of Capbreton, France, collected over a period of ∼1.5 min at a framerate of 1/8 fps by the Pleiades satellite, to a pseudo-video with a framerate of 1 fps. For this purpose, a recently developed method is used, which considers spatial pathways of propagating waves for temporal video reconstruction. The augmented video is subsequently processed with a frequency-based depth inversion algorithm that works largely unsupervised and is openly available. The resulting depth estimates approximate ground truth with an overall depth bias of −0.9 m and an interquartile range of depth errors of 5.1 m. The acquired accuracy is sufficiently high to correctly predict wave heights over the shoreface with a numerical wave model and to find hotspots where wave refraction leads to focusing of wave energy that has potential implications for coastal hazard assessments. A more detailed depth inversion analysis of the nearshore region furthermore demonstrates the possibility to detect sandbars. The combination of image augmentation with a frequency-based depth inversion method shows potential for broad application to temporally sparse satellite imagery and thereby aids in the effort towards globally available coastal bathymetry data., Coastal Engineering, Hydraulic Engineering

Representatives from 14 countries worldwide worked together on improving their monitoring and ultimately their water management to reach the Sustainable Development Goal (SDG) 6 goals by 2030, thereby testing the Information Strategy Model (ISM). This model is developed to support identifying the need for information for water management. In a workshop setting, participants were instructed and subsequently developed the ISM for their own situation. The results show that the ISM fulfils its task of structuring the development and improvement of a monitoring network, but can be enhanced by adding detailed information for specific elements and needs explanation and assistance to be of use.

Representatives from 14 countries worldwide worked together on improving their monitoring and ultimately their water management to reach the Sustainable Development Goal (SDG) 6 goals by 2030, thereby testing the Information Strategy Model (ISM). This model is developed to support identifying the need for information for water management. In a workshop setting, participants were instructed and subsequently developed the ISM for their own situation. The results show that the ISM fulfils its task of structuring the development and improvement of a monitoring network, but can be enhanced by adding detailed information for specific elements and needs explanation and assistance to be of use., Water Resources

The European beach-dune systems are under increasing pressure due to urbanization, beach tourism and the effects of climate change like rising sea level and increased storm intensity. Building with nature solutions (Stive et al., 2013) are advocated as an effective and adaptable approach to protect sandy coasts in the future. This approach however interacts with the increased human use of the beaches- which can have an adverse impact on the efficiency of the building with nature approach. Especially permanent structures influence the natural sand transport dynamics from the beach to the dunes and can have long lasting effects on dune development. To obtain more insight into the influence of buildings on longer term dune development a 3-months ‘Scanex 2020’ field campaign was conducted (Poppema et al., 2021) on Noordwijk beach (52.24 °N, 4.42 °E) to monitor the natural sand development around two sea containers (see Figure 1). In addition on a larger scale the dune development around a permanent beach pavilion was monitored for two years (from August 2019 till August 2021) within the CoastScan project (Vos et al., 2017) with a permanent laser scanner., Coastal Engineering, Optical and Laser Remote Sensing

Storm conditions can lead to excessive dune erosion with potential floods as a consequence. Barrier islands and low-lying countries protected by dunes are especially vulnerable to dune erosion. To properly assess the risks these areas face, a clear understanding of the physical processes during dune erosion is required. An international field experiment was conducted to study dune erosion during storm surges from November 6 2021 until January 6 2022. on the Sand Engine. During the Realdune/Reflex experiment, two prototype un-vegetated dunes of 5.5 m high and 150 m long were built just above the high waterline. Due to a different shoreline orientation and nearshore bathymetry, these dunes eroded differently during moderate storm conditions. 3 storms were captured during the campaign. This abstract presents preliminary results of morphodynamic change during these 3 storms, by means of profile changes and erosion volumes., Coastal Engineering, Environmental Fluid Mechanics

In recent years, dune-in-front-of-dike projects have been carried out at several locations, e.g. at Raversijde and Oosteroever in Belgium and the Hondsbossche dunes in the Netherlands. In the near future, many coastal defence systems require reinforcement to adapt to rising sea levels, and often, natural values along the coasts may also be enhanced. Therefore, it is anticipated that this type of hybrid coastal protection – a mix of grey and green solutions – will become more common in the future. Contrary to grey defence structures, such as earth dikes and rock or concrete structures, dunes are dynamic features. Their level of flood protection depends on their morphological evolution due to aeolian and marine transport processes, vegetation dynamics, and anthropogenic impact. Numerical models are commonly used tools to assess the safety level of dunes and predict their future evolution. In addition to event timescales (storms), the decadal timescale is typically of interest from a coastal management perspective, especially when considering sea level rise. On this timescale, dune build-up through aeolian transport depends on the wind's transport capacity, and the availability of sediment of the appropriate size exposed to the wind is an important process. Sediment availability for aeolian transport is controlled by other sediment transport processes, such as dune erosion and longshore sediment transport, nourishments, and limiting factors, such as surface moisture and armour layers. Simulation of dune evolution at the decadal timescale requires an integrated model approach that accounts for the non-linear interactions between marine and aeolian transport processes in the longshore and cross-shore direction. Reduced complexity approaches are required when these models are applied to large temporal (decades) and spatial scales (kilometres). This study aims to predict medium to long-term dune evolution by developing a new coupled long- term, Coastal Engineering

Representatives from 14 countries worldwide worked together on improving their monitoring and ultimately their water management to reach the Sustainable Development Goal (SDG) 6 goals by 2030, thereby testing the Information Strategy Model (ISM). This model is developed to support identifying the need for information for water management. In a workshop setting, participants were instructed and subsequently developed the ISM for their own situation. The results show that the ISM fulfils its task of structuring the development and improvement of a monitoring network, but can be enhanced by adding detailed information for specific elements and needs explanation and assistance to be of use.

In sandy beach systems, the aeolian sediment transport can be governed by the vertical structure of the sediment layers at the bed surface. Here, data collected with a newly developed sand scraper is presented to determine high-resolution vertical grain size variability and how it is affected by marine and aeolian processes. Sediment samples at up to 2 mm vertical resolution down to 50 mm depth were collected at three beaches: Waldport (Oregon, USA), Noordwijk (the Netherlands) and Duck (North Carolina, USA). The results revealed that the grain size in individual layers can differ considerably from the median grain size of the total sample. The most distinct temporal variability occurred due to marine processes that resulted in significant morphological changes in the intertidal zone. The marine processes during high water resulted both in fining and coarsening of the surface sediment. Especially near the upper limit of wave runup, the formation of a veneer of coarse sediment was observed. Although the expected coarsening of the near-surface grain size during aeolian transport events was observed at times, the opposite trend also occurred. The latter could be explained by the formation and propagation of aeolian bedforms within the intertidal zone locally resulting in sediment fining at the bed surface. The presented data lays the basis for future sediment sampling strategies and sediment transport models that investigate the feedbacks between marine and aeolian transport, and the vertical variability of the grain size distribution., Coastal Engineering, Environmental Fluid Mechanics

Sandy nourishments can provide additional sediment to the coastal system to maintain its recreational or safety function under rising sea levels. These nourishments can be implemented at sandy beach systems, but can also be used to reinforce gray coastal infrastructure (e.g., dams, dikes, seawalls). The Hondsbossche Dunes project is a combined shoreface, beach, and dune nourishment of 35 million m3 sand. The nourishment was built to replace the flood protection function of an old sea-dike while creating additional space for nature and recreation. This paper presents the evolution of this newly created sandy beach system in the first 5 years after implementation based on bathymetric and topographic surveys, acquired every three to six months. A significant coastline curvature is created by the nourishment leading to erosion in the central 7 km bordered by zones with accretion. However, over the five-year period, net volume losses from the project area were less than 5% of the initial nourished sand volume. The man-made cross-shore beach profile rapidly mimics the characteristics of adjacent beaches. The slope of the surfzone is adjusted within two winters to a similar slope. The initially wide beaches (i.e., up to 225 m) are reduced to about 100 m-wide. Simultaneously, the dune volume has increased and the dune foot migrated seaward at the entire nourished site, regardless of whether the subaqueous profile gained or lost sediment. Our results show that the Hondsbossche Dunes nourishment, built with a natural slope and wide beach, created a positive sediment balance in the dune for a prolonged period after placement. As such, natural forces in the years after implementation provided a significant contribution to the growth in dune volume and related safety against flooding., Coastal Engineering, Hydraulic Engineering

Coastal aeolian sediment transport is influenced by supply-limiting factors caused by sediment sorting by grain size. Sorting processes can lead to coarsening of the bed surface and influence the formation of aeolian ripples. However, the influence sorting processes and bedforms might have on the magnitude of the transport is not fully understood. This study explores sorting processes and their influence on the magnitude and mode of aeolian transport by using sediment tracers. Sand was painted in different colors according to particle size and placed on a supratidal beach in Noordwijk, the Netherlands. Several experiments were conducted with varying wind speeds. Surface sampling and cameras tracked the sand color movement on the bed surface, and wind velocity was measured. The tracer experiments showed that ripples developed in moderate wind conditions. Once the ripples had formed, the supply of finer tracer grains in the downwind direction decreased over time, while the supply of coarser grains remained constant. A linear relationship between ripple migration speed and wind speed was found. For higher wind speeds, no ripples or differences in transport of grain size fractions were observed. Instead, alternating phases of erosion and deposition of the bed surface were observed, which could not be related to local variations in wind velocity. Based on these results and literature, a conceptual model was developed for an active bed surface layer with two transport regimes corresponding to moderate (I) and high (II) wind speeds. The conceptual model is intended to guide the selection of aeolian sediment transport models as a function of wind speed, bed characteristics, and upwind sediment supply. For Regime I, transport could be modeled using a linear relationship between sediment transport and wind speed and for Regime II using a third power relationship in combination with a process-based model accounting for supply limitations., Coastal Engineering, Environmental Fluid Mechanics

Sandy coasts form the interface between land and sea and their morphologies are highly dynamic. A combination of human and natural forcing results in morphologic changes affecting both nature values and coastal safety. Terrestrial laser scanning (TLS) is a technique enabling near-continuous monitoring of the changing morphology of a sandy beach-dune system with centimetre-order accuracy. In Kijkduin, The Netherlands, a laser scanner sampled one kilometre of coast at hourly intervals for about six months. This resulted in over 4,000 consecutive topographic scans of around one million points each, at decimetre-order point spacing. Analysis of the resulting dataset will offer new insights into the morphological behaviour of the beach-dune system at hourly to monthly time scales, ultimately increasing our fundamental scientific understanding of these complex geographic systems. It further provides the basis for developing novel algorithms to extract morphodynamic and geodetic information from this unique 4D spatiotemporal dataset. Finally, experiences from this TLS setup support the development of improved near-continuous 3D observation of both natural and anthropogenic scenes in general., Coastal Engineering, Optical and Laser Remote Sensing, Hydraulic Engineering

Optical satellite images of the nearshore water surface offer the possibility to invert water depths and thereby constitute the underlying bathymetry. Depth inversion techniques based on surface wave patterns can handle clear and turbid waters in a variety of global coastal environments. Common depth inversion algorithms require video from shore-based camera stations, UAVs or Xband-radars with a typical duration of minutes and at framerates of 1–2 fps to find relevant wave frequencies. These requirements are often not met by satellite imagery. In this paper, satellite imagery is augmented from a sequence of 12 images of Capbreton, France, collected over a period of ∼1.5 min at a framerate of 1/8 fps by the Pleiades satellite, to a pseudo-video with a framerate of 1 fps. For this purpose, a recently developed method is used, which considers spatial pathways of propagating waves for temporal video reconstruction. The augmented video is subsequently processed with a frequency-based depth inversion algorithm that works largely unsupervised and is openly available. The resulting depth estimates approximate ground truth with an overall depth bias of −0.9 m and an interquartile range of depth errors of 5.1 m. The acquired accuracy is sufficiently high to correctly predict wave heights over the shoreface with a numerical wave model and to find hotspots where wave refraction leads to focusing of wave energy that has potential implications for coastal hazard assessments. A more detailed depth inversion analysis of the nearshore region furthermore demonstrates the possibility to detect sandbars. The combination of image augmentation with a frequency-based depth inversion method shows potential for broad application to temporally sparse satellite imagery and thereby aids in the effort towards globally available coastal bathymetry data., Coastal Engineering, Hydraulic Engineering

Representatives from 14 countries worldwide worked together on improving their monitoring and ultimately their water management to reach the Sustainable Development Goal (SDG) 6 goals by 2030, thereby testing the Information Strategy Model (ISM). This model is developed to support identifying the need for information for water management. In a workshop setting, participants were instructed and subsequently developed the ISM for their own situation. The results show that the ISM fulfils its task of structuring the development and improvement of a monitoring network, but can be enhanced by adding detailed information for specific elements and needs explanation and assistance to be of use., Water Resources

Several studies have observed an inverse relationship between attention deficit hyperactivity disorder (ADHD)-related behavior of children, as reported by parents or teachers, and the amount of green space in their residential environment. Research using other, more objective measures to determine ADHD prevalence is scarce and could strengthen the evidence base considerably. In this study, it is investigated whether a similar beneficial association will be observed if the use of ADHD-related medication is selected as an outcome measure. More specifically, registry data from a health insurance company on the reimbursement of ADHD-related medication in 2011 were available for 248,270 children between 5 and 12 years of age. Amounts of green space within 250 and 500 m of the home address were calculated. Multilevel logistic regression analyses for the prevalence of use were conducted, including the following covariates: sex, age, urbanity of the neighborhood, neighborhood socioeconomic status (SES), and percentage of people with a non-Western migration background in the neighborhood population. Results showed that the amount of green space was inversely related to the prevalence of use of ADHD medication. Moreover, the relationship was strongest among children living in the least wealthy neighborhoods and absent among those living in the wealthiest neighborhoods. Results also show that in less wealthy neighborhoods, there is, on average, less green space available nearby: children who are likely to benefit most from nearby green space tend to have the least of it.

Locally produced rapeseed meal (RSM) and sunflower seed meal (SFM) are preeminent alternatives in monogastric feed to reduce the reliance of the European Union (EU) on soy imports. However, RSM and SFM have greater fiber contents compared with soybean meal (SBM). Currently, the lack of information on the composition of RSM and SFM fibers, their degradation and influence on digestive processes hampers accurate prediction of their nutritional value when included in pig and poultry diets, and limits the development of strategies to enhance RSM and SFM fiber degradation. This review emphasizes the diversity of fibers, found in RSM, SFM and SBM, identifies recalcitrant non-starch polysaccharides (NSP) of these meals in monogastric animals, and indicates opportunities to improve degradation of these fibers. In pigs, undegraded NSP from RSM represent ~65 g/kg dry matter (DM), due to the limited degradation of uronyl-rich polysaccharides (0.50) and cellulose (0.66). SFM has the highest recalcitrant NSP content (~147 g/kg DM), because of poor degradation of xylosyl-rich polysaccharides (0.25) and cellulose (0.38). SBM has the lowest recalcitrant NSP content (~39 g/kg DM), mainly limited by degradation of cellulose (0.57), non-cellulosic glucosyl (0.53) and xylosyl-rich polysaccharides (0.61–0.65). In chickens, undegraded NSP represent ~165 g/kg DM for SBM and ~197 g/kg DM for RSM. Even the degradation of soluble fiber is often not complete. Substantial improvements in fiber degradation can be achieved using technologies targeting ingredient-specific recalcitrant fibers, potentially increasing energy yield from the meals by fermentation, and releasing encapsulated nutrients. For example, multi-carbohydrase addition improved degradation of RSM fibers in chickens by 113%, and in an in vitro pig model by 122%. In another study, cellulases improved RSM fiber degradation in an in sacco pig model by ~35%. Typically, synergistic effects between pectinases and (hemi)cellulases are se

Semi-supervised learning (SSL) methods attempt to achieve better classification of unseen data through the use of unlabeled data than can be achieved by learning from the available labeled data alone. Most SSL methods require the user to familiarize themselves with novel, complex concepts and to ensure the underlying assumptions made by these methods match the problem structure, or they risk a decrease in predictive performance. In this paper, we present the reliable semi-supervised ensemble learning (RESSEL) method, which exploits unlabeled data by using it to generate diverse classifiers through self-training and combines these classifiers into an ensemble for prediction. Our method functions as a wrapper around a supervised base classifier and refrains from introducing additional problem dependent assumptions. We conduct experiments on a number of commonly used data sets to prove its merit. The results show RESSEL improves significantly upon the supervised alternatives, provided that the base classifier which is used is able to produce adequate probability-based rankings. It is shown that RESSEL is reliable in that it delivers results comparable to supervised learning methods if this requirement is not met, while the method also broadens the range of good parameter values. Furthermore, RESSEL is demonstrated to outperform existing self-labeled wrapper approaches.

Mapping coastal bathymetry from remote sensing becomes increasingly more attractive for the coastal community. It is facilitated by a rising availability of drone and satellite data, advances in data science, and an open-source mindset. Coastal bathymetry, but also wave directions, celerity and near-surface currents can simultaneously be derived from aerial video of a wave field. However, the required video processing is usually extensive, requires skilled supervision, and is tailored to a fieldsite. This study proposes a video-processing algorithm that resolves these issues. It automatically adapts to the video data and continuously returns mapping updates and thereby aims to make wave-based remote sensing more inclusive to the coastal community. The code architecture for the first time includes the dynamic mode decomposition (DMD) to reduce the data complexity of wavefield video. The DMD is paired with loss-functions to handle spectral noise and a novel spectral storage system and Kalman filter to achieve fast converging measurements. The algorithm is showcased for fieldsites in the USA, the UK, the Netherlands, and Australia. The performance with respect to mapping bathymetry was validated using ground truth data. It was demonstrated that merely 32 s of video footage is needed for a first mapping update with average depth errors of 0.9–2.6 m. These further reduced to 0.5–1.4 m as the videos continued and more mapping updates were returned. Simultaneously, coherent maps for wave direction and celerity were achieved as well as maps of local near-surface currents. The algorithm is capable of mapping the coastal parameters on-the-fly and thereby offers analysis of video feeds, such as from drones or operational camera installations. Hence, the innovative application of analysis techniques like the DMD enables both accurate and unprecedentedly fast coastal reconnaissance. The source code and data of this article are openly available., Coastal Engineering, Hydraulic Engineering

In this paper, a new approach to model wave‐driven, cross‐shore shoreline change incorporating multiple timescales is introduced. As a base, we use the equilibrium shoreline prediction model ShoreFor that accounts for a single timescale only. High‐resolution shoreline data collected at three distinctly different study sites is used to train the new data‐driven model. In addition to the direct forcing approach used in most models, here two additional terms are introduced: a time-upscaling and a time‐downscaling term. The upscaling term accounts for the persistent effect of short‐term events, such as storms, on the shoreline position. The downscaling term accounts for the effect of long‐term shoreline modulations, caused by, for example, climate variability, on shorter event impacts. The multi‐timescale model shows improvement compared to the original ShoreFor model (a normalized mean square error improvement during validation of 18 to 59%) at the three contrasted sandy beaches. Moreover, it gains insight in the various timescales (storms to inter‐an-nual) and reveals their interactions that cause shoreline change. We find that extreme forcing events have a persistent shoreline impact and cause 57–73% of the shoreline variability at the three sites. Moreover, long‐term shoreline trends affect short‐term forcing event impacts and determine 20– 27% of the shoreline variability., Coastal Engineering, Environmental Fluid Mechanics

Sea level is rising due to climate change and is expected to influence the development and dynamics of coastal dunes. However, the anticipated changes to coastal dunes have not yet been demonstrated using field data. Here, we provide evidence of dune translation that is characterized by a linear increase of the dune toe elevation on the order of 13–15 mm/year during recent decades along the Dutch coast. This rate of increase is a remarkable 7–8 times greater than the measured sea level rise. The observed vertical dune toe translation coincides with seaward movement of the dune toe (i.e., progradation), which shows similarities to prograding coasts in the Holocene both along the Dutch coast and elsewhere. Thus, we suspect that other locations besides the Dutch coast might also show such large ratios between sea level rise and dune toe elevation increase. This phenomenon might significantly influence the expected impact of sea level rise and climate change adaptation measures., Coastal Engineering