Flood hazard in Ratnapura, Sri Lanka: Individual attitudes vs collective action
Abstract In Ratnapura monsoonal flooding is a chronic problem of which the residents are acutely aware. Responses to structured interviews indicated that a wide range of actions are employed to reduce flood impact, although these actions are not perceived as specific adjustments to flooding. The only widely acknowledged means of mitigating the flood threat is government action. Dependency on government action reflects the government's role in dispensing aid to flood victims. While relief programmes do reduce personal, short-term losses, they simultaneously encourage resettlement in high-risk areas. In seeking a viable, long-term management policy, the Sri Lankan government recently adopted a plan to move the municipality of Ratnapura to invulnerable high ground. In making the decision to relocate, however, the attitudes of the residents were not evaluated, and government officials seemed unconcerned that residents viewed relocation as an unacceptable solution to the problem. Although individual attitudes concerning residential satisfaction in the context of the flood hazard varied with factors such as income, length of residency and land tenure, an overwhelming number of residents adamantly maintained that they would not move to the new town.
PLANNING FOR HAZARDS IN EVERYDAY LANDSCAPES
A river's rise, a crustal fracture, a reduction in soil moisture, an increase in windspeed - all are acts of nature. Floods, earthquakes, droughts or storms are acts percipitated by men. This is one central finding after 15 years of intensive geographical research on natural hazards, their geophysical dimensions, human impact and social response. There are no floods unless there are people, buildings or livestock to be damaged. The responsibility falls on those who use and inhabit the large areas of the earth subject to high recurrent natural hazards, and even more directly on those who plan land use and design habitations. Suggestions are made for development of more flexible technical and social responses to hazards which result in drought, fog, frost, soil creep or expansive soils.
Impact of Nuclear Data Uncertainties on Transmutation of Actinides in Accelerator-Driven Assemblies
Abstract The potential impact of nuclear data uncertainties on a large number of performance parameters of reactor cores dedicated to the transmutation of radioactive wastes is discussed. An uncertainty analysis has been performed based on sensitivity theory, which underlines the cross sections, the energy range, and the isotopes that are responsible for the most significant uncertainties. To provide guidelines on priorities for new evaluations or validation experiments, required accuracies on specific nuclear data have been derived, accounting for target accuracies on major design parameters. The required accuracies (mostly in the energy region below 20 MeV), in particular for minor actinide data, are of the same order of magnitude of the achieved accuracies on major actinides. Specific requirements also concern the improvement of minor actinide data related to decay heat and effective delayed-neutron fraction assessment.