Coastal management and disaster planning on the basis of flood risk calculations

Recent studies showed that one third of the Belgian coastline is not sufficiently protected against severe storm events. Therefore coastal protection plans are set up to assure a minimum safety standard for the entire coastline. Flood risk calculations constitute the main input parameter for the concept and planning phases. Since 100% safety can never be guaranteed, contingency plans are constructed to reduce the remaining flood risks. Flood risk calculations are a powerful communicative and operational instrument to use between engineers and experts on the field, thus forming the link between coastal management and disaster planning

Scientific support regarding hydrodynamics and sand transport in the coastal zone: literature and data review coastal zone Zeebrugge - Zwin

In this report the available literature and data relevant for the coastal zone between Zeebrugge and the Zwin is summarised.Since the extension of the harbour of Zeebrugge (finalised in 1986) a lot of bathymetrical data are available. With these data the evolution around Zeebrugge (including the Western part, area around the harbour breakwaters, Baai van Heist, the beaches of Knokke and the Appelzak gully) can be reconstructed. But also before this extension some data are available, such that the difference pre and post extension can be compared.Other data and literature are also described, including numerical modelling of currents and morphology, detailed hydrodynamic and sediment transport measuring campaigns and analysis of the sediment composition.In front of Knokke-Heist the beaches are eroding due to the presence of the Appelzak-gully. The Appelzak shows a long term landward movement. However the movement and development of the gully seems to slow down during the last 10 years. Although confirmation is needed (both based on further trend analysis and numerical modelling), this might suggest that big scale measures to reduce erosion, might be less effective Possibilities for the slow down are the more equilibrium state of the system after the extension of the harbour of Zeebrugge and the influence of the large nourishments in the last decade .Consequently, also the erosion in front of Knokke-Heist is clearly slowing down during the last decade

Scientific support regarding hydrodynamics and sand transport in the coastal zone: calibration of a Long term morphological model of the Belgian shelf

Longshore sediment transport in the surf zone plays a considerable role in the long-term morphological behaviour of the Belgian coast. Based on previous efforts (Zimmermann et al., 2013b; Zimmermann et al., 2013), this report firstly presents a 2D numerical model which covers almost the entire Belgian coast from Nieuwpoort to the Zwin. With the MorMerge online-parallel approach the time horizon for modelling long term morphology in the surf zone was successfully increased to 10 years. Compared with the measurement data, most major morphological changes in the surf zone are well captured qualitatively by the 2D numerical model with an exception of the sedimentation in the Baai van Heist. The modelled sedimentation/erosion is further quantitatively compared with beach accretion/erosion trends of the last 25 years reported in Houthuys (2012). This model still shows a reasonable agreement and its quality is discussed. The sedimentation in the Baai van Heist is specially investigated by an updated 2D and later a new 3D model. For a further validation of the model used in this study, another 3 models OKNO, Zeebrugge and MU-HEIST are introduced and their results are compared with that of the model used in this study. After a series of sensitivity tests a roughness map is employed to update the 2D model, but the updated 2D model seems to be still unable to reproduce the sedimentation in the Baai van Heist properly, especially from the quantitative point of view. To avoid the Gallapatti time scale, a new 3D model is built up, and driven by boundary condition of full spring-neap tides rather than representative ones imposed in the 2D model. With the technique of time-varying MorFac and multiple sediment fractions, the 3D model shows a quite good potential to reproduce the sedimentation in the Baai van Heist. Based on the promising result produced by the 3D model, additional work is proposed for further investigation and research in the future

Scientific support regarding hydrodynamics and sand transport in the coastal zone: hindcast of the morphological impact of the 5-6 December 2013 storm using XBeach

A storm occurred in the North Sea on 5-6 December 2013 (also known as the Sinterklaasstorm) which generated high surge levels and moderately high wave heights along the Belgian coast, resulting in beach and dune erosion. Measurements of beach profile change along 122 cross-shore survey transects were compared with the numerical model XBeach. First, a novel configuration for XBeach was developed that takes into account the effects of wave directional spreading since XBeach cannot resolve directionally spreading of long waves in 1D mode (which is generally used to predict cross-shore profile change). The effect of wave directional spreading on hydrodynamics and sediment transport is investigated using idealized and realistic simulations. Idealized simulations show that the near-shore long wave field is more energetic in 1D than in an equivalent 2D model with an alongshore-uniform bathymetry. Realistic storm scenarios show that this leads to predicted erosion volumes that are 25-57% higher than in the 2D model. Sparse 2D models with 5 to 8 alongshore grid cells provide a reasonable approximation (both for hydrodynamics and sediment transport) of the full 2D model (with 50 alongshore grid cells) at a lower computational cost. The December 2013 storm was therefore simulated using a sparse 2D model with 5 grid cells in the alongshore direction. Good agreement with measured erosion volumes was found when using a recently established set of calibration values provided by Deltares. Default calibration values from an older version of XBeach lead to an overestimation of the erosion volumes, as does the use of a 1D model instead of a sparse 2D model. The sensitivity of the predicted erosion volumes to increased surge levels and wave heights was also investigated

Crystalline Electric Field Effects in CeMIn5: Superconductivity and the Influence of Kondo Spin Fluctuations

We have measured the crystalline electric field (CEF) excitations of the CeMIn5 (M = Co, Rh, Ir) series of heavy fermion superconductors by means of inelastic neutron scattering. Fits to a CEF model reproduce the inelastic neutron scattering spectra and the high temperature magnetic susceptibility. The CEF parameters, energy level splittings, and wavefunctions are tabulated for each member of the CeMIn5 series and compared to each other as well as to the results of previous measurements. Our results indicate that the CEF level splitting in all three materials is similar, and can be thought of as being derived from the cubic parent compound CeIn3 in which an excited state quartet at ~12 meV is split into two doublets by the lower symmetry of the tetragonal environment of the CeMIn5 materials. In each case, the CEF excitations are observed as broad lines in the inelastic neutron scattering spectrum. We attribute this broadening to Kondo hybridization of the localized f moments with the conduction electrons. The evolution of the superconducting transition temperatures in the different members of CeMIn5 can then be understood as a direct consequence of the strength of this hybridization. Due to the importance of Kondo spin fluctuations in these materials, we also present calculations within the non-crossing approximation (NCA) to the Anderson impurity model including the effect of CEF level splitting for the inelastic neutron scattering spectra and the magnetic susceptibility.Comment: 30 pages, 6 figures, submitted to Phys. Rev.

Crystalline Electric Field Excitations in the Heavy Fermion Superconductor CeCoIn_5

The crystalline electric field (CEF) energy level scheme of the heavy fermion superconductor CeCoIn_5 has been determined by means of inelastic neutron scattering (INS). Peaks observed in the INS spectra at 8 meV and 27 meV with incident neutron energies between E_i=30-60 meV and at a temperature T = 10 K correspond to transitions from the ground state to the two excited states, respectively. The wavevector and temperature dependence of these peaks are consistent with CEF excitations. Fits of the data to a CEF model yield the CEF parameters B^0_2=-0.80 meV, B^0_4=0.059 meV, and |B^4_4|= 0.137 meV corresponding to an energy level scheme: Gamma_7^(1) (0)[=0.487|+/-5/2> - 0.873|-/+3/2>], Gamma_7^(2) (8.6 meV, 100 K), and Gamma_6 (24.4 meV, 283 K).Comment: uses latex packages revtex4,amsmath,graphicx,natbib, 9th Annual MMM-Intermag Conference, (Accepted for publication in J. Appl. Phys.) 7 pages, 2 figure

Single-cell reconstruction of follicular remodeling in the human adult ovary

The ovary is perhaps the most dynamic organ in the human body, only rivaled by the uterus. The molecular mechanisms that regulate follicular growth and regression, ensuring ovarian tissue homeostasis, remain elusive. We have performed single-cell RNA-sequencing using human adult ovaries to provide a map of the molecular signature of growing and regressing follicular populations. We have identified different types of granulosa and theca cells and detected local production of components of the complement system by (atretic) theca cells and stromal cells. We also have detected a mixture of adaptive and innate immune cells, as well as several types of endothelial and smooth muscle cells to aid the remodeling process. Our results highlight the relevance of mapping whole adult organs at the single-cell level and reflect ongoing efforts to map the human body. The association between complement system and follicular remodeling may provide key insights in reproductive biology and (in) fertility