Reducing the impact of wave attack: dunes as natural buffers

Coastal dune systems, with their self-regenerating capacity after storm erosion, represent natural defense zones against flooding of the hinterland. Condition: the total dune volume exceeds a certain minimum value related to the safety standard. As such, coastal dune systems represent natural buffers to climate change. To maintain the functions of the dune system at a certain level under conditions of sea level rise, the dunes require an input of sand proportional to the rate of sea level rise. Focus of the research is on the problem of how sediment supply and dune management may be optimized under conditions of climate change in order to sustainably preserve the safety function of the dunes in harmony with other functions of the system. The aim of this project is to derive a model of dune development and apply it together with other models and expert judgment, to develop and evaluate a set of potential dune management strategies, aimed at improvement of the climate buffer function of dunes. This text is an extract of the full project proposal

Corrosion of alloy 800H and the effect of surface-applied CeO2 in a sulphidizing/oxidizing/carburizing environment at 700°C

The corrosion behavior of a wrought austenitic Fe-20Cr-32Ni steel, Alloy 800H, was studied in a simulated coal-gasification atmosphere at 700°C for exposure times up to 2500 hr. The influence of preoxidation and CeO2-surface application followed by preoxidation on the corrosion resistance of this material was assessed. The improvement in the corrosion resistance due to preoxidation of the blank material was small, whereas the effect of the CeO2-treatment was significant. This difference is thought to be due to better scale adherence in the case of CeO2-surface application

The concept of matric flux potential applied to simulation of evaporation from soil.

Two simulation models of evaporation were based respectively on (a) soil matric flux potential and (b) soil hydraulic conductivity and water potential. Mathematical analysis showed that the former method gave a lower and more accurate estimate of soil water movement in unsaturated soil, and therefore of evaporation from the soil. The difference between the accuracy of the two methods tended to be greatest in soils of coarse texture. The matric flux potential method required less computer time than the other method did. (Abstract retrieved from CAB Abstracts by CABI’s permission

The properties of protective oxide scales containing cerium on alloy 800H in oxidizing and oxidizing/sulphidizing environments

The corrosion protection of oxide scales formed by electrophoretic deposition in a cerium-containing sol on Alloy 800H, a 32Ni-20Cr steel, followed by firing in air at 1123 K was studied in oxidizing and mixed oxidizing/sulphidizing environments at elevated temperatures. In particular, the influence of type of sol solvent, sol concentration, and thickness of deposited layer on the protection were studied. An optimized treatment was deduced which led to a significant improvement in corrosion behavior in oxidizing/sulphidizing environments.\u

Environnement humain de l'érosion

Dans le cadre des évaluations économiques des mesures de conservation des eaux et du sol, on propose d'utiliser des méthodes et modèles existants pour déterminer les effets de ces mesures sur l'érosion et sur les bilans d'eau et d'éléments nutritifs et ensuite les effets des changements sur les rendements. Dans ce texte on présente des "feuilles de calcul", y incluant ces bilans et effets, afin de calculer les bénéfices des mesures de CES. Un exemple concerne l'évaluation économique des cordons pierreux au Burkina Faso. (Résumé d'auteur

Water movement in layered soils. 2. Experimental confirmation of a simulation model.

For predicting the rain infiltration front in a layered soil the simulation model written in CSMP (Continuous System Modelling Program) described by van Keulen and van Beek (1971) gave results that were in good agreement with the predicted infiltration behaviour. [132.3: 968.114. (Abstract retrieved from CAB Abstracts by CABI’s permission