31 research outputs found
Increased plasma thrombomodulin levels in pre-eclampsia: endothelial damage or renal insufficiencies?
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Tissue factor and total tissue factor pathway inhibitor levels in coronary artery disease: correlation with the severity of atheromatosis
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Fibrinolytic system assessment in hemodialysis patients with and without thrombotic complications
No full textDecision-making in the case of a flood-threat: Implementation of the new risk-approach
No full textThe Netherlands recently developed a new risk approach for flood management. The approach changed the safety standards in the Water-Act. The safety standard used to be an exceedance probability of the design water level, and the flood defence was supposed not to fail for all water levels below this level. Since knowledge regarding the actual strength of flood-defences has improved, a change has been made towards expressing the safety standard as a failure probability. The main difference between both approaches finds its way in the explicit inclusion of all sorts of failure-mechanisms (new approach), instead of focusing on the design waterlevel (old approach). The new safety standards are supported with a cost-benefit analysis where one takes account of the economic value of fatalities. Although improvements of the flood defences already started, the Dutch safety protocol for emergency measures still relies on the old approach, based on threshold-waterlevels. The question is, if emergency-measures are still taken in time when knowledge of the new risk-approach is applied. Therefore, this research developed a decision-method for flood emergency-measures. In our method, the call for evacuation is based on the same risk management approach as used to define the new safety standards. Evacuation can save loss of life, but flood-events and dike breaches are often uncertain until they happen. On the other hand, certain costs are involved if a call for evacuation is made. Therefore, the method assessed the threshold to support the decision to evacuate or not to evacuate, together with a social cost-benefit analysis including a monetary value for a fatality. The proposed method is developed on basis of a theoretical example and finally applied to dikering-area 43 in the Netherlands. By use of measured and forecasted water levels, and fragility curves describing the strength of the flood defences, the conditional probability of failure is defined to support the decisions “evacuation” and “no evacuation”. When the expected costs for evacuation are smaller than the expected costs for no evacuation, the measure becomes worthwhile. Costs are related to economy (a fraction of the GDP) and fatalities by the evacuation-process (car-accidents, hospitals). Benefits are defined by the prevented loss of life and the value of moved goods. These rely on the uncertain flood-event. Probabilities and scenarios can finally be combined to calculate the expected costs for a decision. By doing so, one can find the moment in the discharge-wave one should decide to act. This decision-moment is finally compared with current emergency-procedures, based on threshold-waterlevels. These results make clear if emergency-measures should be revised.Civil Engineering and GeosciencesHydraulic Engineerin
