How the Belgian wind farm business made us discover the challenging environment of marine sand dunes

During the last decade, it has become clear that sand dunes are important features in the Belgian wind farm concession area. Because they influence not only the design seabed levels, but also the hydrodynamic forcings and installation methods for both cable and foundations, the study of the seabed morphodynamics is essential for all wind farm projects. This paper starts with an overview of the geographic and morphological setting of the Belgian wind farm concession areas and presents an overview of the key features of the bedforms in the different concessions. Next the importance and impact of the sand dunes during the design and development of these wind farms is illustrated by exploring the different types of studies and investigations which have been performed in relation to seabed & morphology, the hydrodynamic loadings, the installation methods and the environmental impact assessments

Evolution of marine storminess in the Belgian part of the North Sea

Severe storms have affected European coast lines in the past but knowledge on changes in storminess for the last decades is still sparse. Climate change is assumed to be a main driving factor with the potential to induce changes on the intensity, duration and frequency of powerful marine storms, including a long-term influence on peak wind speeds, surges and waves. It is, therefore, important to investigate whether in the last decades changes in the magnitude of storms, their duration and frequency could be observed. Understanding trends in storminess in the last decades will help to better prepare coastal managers for future events, taking into account potential changes on storm occurrence and magnitude to improve planning of mitigation and adaptation strategies. The purpose of this study was to focus on the evolution of extreme wind conditions, wave height and storm surge levels in the North Sea Region, especially in the Belgian part of the North Sea (BPNS). Based on the analysis performed it is concluded that no clear trend can be observed for the occurrence of significant increasing extreme wind speeds over the BPNS. Furthermore, one can conclude that not enough scientific evidence is available to support scenarios with increased wave height or storminess

Use of dual carbon–chlorine isotope analysis to assess the degradation pathways of 1,1,1-trichloroethane in groundwater

Compound-specific isotope analysis (CSIA) is a powerful tool to track contaminant fate in groundwater. However, the application of CSIA to chlorinated ethanes has received little attention so far. These compounds are toxic and prevalent groundwater contaminants of environmental concern. The high susceptibility of chlorinated ethanes like 1,1,1-trichloroethane (1,1,1-TCA) to be transformed via different competing pathways (biotic and abiotic) complicates the assessment of their fate in the subsurface. In this study, the use of a dual C-Cl isotope approach to identify the active degradation pathways of 1,1,1- TCA is evaluated for the first time in an aerobic aquifer impacted by 1,1,1-TCA and trichloroethylene (TCE) with concentrations of up to 20 mg/L and 3.4 mg/L, respectively. The reaction-specific dual carbon-chlorine (C-Cl) isotope trends determined in a recent laboratory study illustrated the potential of a dual isotope approach to identify contaminant degradation pathways of 1,1,1-TCA. Compared to the dual isotope slopes (Δδ13C/Δδ37CI) previously determined in the laboratory for dehydrohalogenation/hydrolysis (DH/HY, 0.33 ± 0.04) and oxidation by persulfate (∞), the slope determined from field samples (0.6 ± 0.2, r2 = 0.75) is closer to the one observed for DH/HY, pointing to DH/HY as the predominant degradation pathway of 1,1,1-TCA in the aquifer. The observed deviation could be explained by a minor contribution of additional degradation processes. This result, along with the little degradation of TCE determined from isotope measurements, confirmed that 1,1,1-TCA is the main source of the 1,1-dichlorethylene (1,1-DCE) detected in the aquifer with concentrations of up to 10 mg/L. This study demonstrates that a dual C-Cl isotope approach can strongly improve the qualitative and quantitative assessment of 1,1,1-TCA degradation processes in the field

A full scale propeller wash erosion test on heterogeneous cohesive material

As part of a life-cycle cost analysis for the construction of a harbour basin, a full scale erosion test on a dredged slope was undertaken using a test vessel. The objective of the test was to estimate the erosion rate of the in-situ material in order to predict the final profile of the dredged slope at the end of the design life following exposure to propeller wash generated by various manoeuvring vessels. Based on theoretical formulae, a test protocol of percentages of the installed engine power to be applied was defined, aiming to generate a steady propeller flow on the slope as a function of the tide. A pre-installed anchoring point ensured the test vessel maintained a steady position during the test and the pre-defined percentages of the installed engine power were applied as a function of the tidal levels measured during the test. Several interim bathymetric surveys were undertaken in order to monitor and record the progress of the erosion over the tested slope. Orientation and location of the vessel were monitored by satellite positioning, tides were recorded by installed gauges and actual flow velocities logged by a current meter. A time stamped geo-database was developed to model the theoretical distribution of the velocities at any moment of the test. Through the analysis of the tests results, a curve defining the erosion rate as a function of the velocity at the slope was derived from the model and was verified by comparing generated cross-sections against actual surveys. Results were then extrapolated to represent the situation at the end of the design life of the harbour in order to assess whether protection of the slopes was required to preserve the integrity of the marine structures adjacent to the harbour basin. Results were also used to define an appropriate monitoring program for the dredged slopes which had potential for scour generated by propeller wash

How children eat may contribute to rising levels of obesity children's eating behaviours: An intergenerational study of family influences

The term ‘obesogenic environment’ is rapidly becoming part of common phraseology. However, the influence of the family and the home environment on children's eating behaviours is little understood. Research that explores the impact of this micro environment and intergenerational influences affecting children's eating behaviours is long overdue. A qualitative, grounded theory approach, incorporating focus groups and semi-structured interviews, was used to investigate the family environment and specifically, the food culture of different generations within families. What emerged was a substantive theory based on ‘ordering of eating’ that explains differences in eating behaviours within and between families. Whereas at one time family eating was highly ordered and structured, typified by the grandparent generation, nowadays family eating behaviours are more haphazard and less ordered, evidenced by the way the current generation of children eat. Most importantly, in families with an obese child eating is less ordered compared with those families with a normal weight child. Ordering of eating' is a unique concept to emerge. It shows that an understanding of the eating process is crucial to the development and improvement of interventions targeted at addressing childhood obesity within the family context

All quiet on the sea bottom front? Lessons from the morphodynamic monitoring

The impact of the construction of the offshore wind farms on the turbidity was local and temporary, with no significant difference between the before and after situation. Erosion pits were formed, both around gravity based foundations and monopiles, though erosion protection provided the necessary stability. Dredging/filling works were more complex than expected. Large volumes of sand were lost and sand pits did not refill naturally. In dune migrating areas the coverage of export cables could not be guaranteed. As a result they are now buried 1 m below the base of the dunes

Understanding body image in physical education

Body image disturbance in children and adolescents has negative implications for psychological and physical well-being. To positively impact well-being, it is important to explore factors that influence body image and to identify strategies that can be used to reduce body image disturbance. The school curriculum can play a significant role in shaping how children and adolescents experience their bodies. Within this school curriculum, physical education lessons represent one of the only school subjects in which the body is a focus of curricular outcomes. In physical education, the body is judged for physical ability but is also situated in a space that provides the potential for social comparisons and body judgements. Significant attention has been paid to the development of classroom-based interventions that aim at reducing body image disturbance, yet physical education has largely been ignored as a context in which one can effectively intervene. This paper reviews current knowledge on the relationship between physical education and body image disturbance by using the cognitive-behavioural model of body image developments as a guiding framework. It also considers the contribution that physical education could make to wider school-based interventions