Heavy Precipitation and Floods
- Resumen
- The average annual economic flood damage worldwide has increased by order of magnitude in the last four decades, in inflation-adjusted monetary units. This has been due to socio-economic changes (increasing population and assets in floodprone areas and land-use change); terrestrial (land-cover change and reduction of natural storage); and climatic factors. The anthropogenic increase in atmospheric concentration of greenhouse gases leads to enhancement of the greenhouse effect, resultingin the global warming and such impacts as glacier melt, and sealevel rise. Increase of temperature causes intensification of the hydrological cycle, by which floods and droughts get more frequent and/or more extreme. Indeed, several examples of occurrence of a drought and a flood in the same area in a short time interval have been observed recently (e.g. in Spain). The moisture-holding capacity of the atmosphere has been increasing with temperature, at a rate of about 7% per 1°C, with consequence to flood risk. Observational evidence indicates increasing probability (and number) of heavy precipitation events in the warming climate. However, due to strong natural variability in high river flows and multiple flood generating mechanisms, no ubiquitous, and statistically significant, change has been documented. Regional changes in timing of floods have been observed in many areas, with increasing late autumn and (rain-caused) winter floods. In contrast, the number and intensity of snowmelt and ice-jam-related floods has been decreasing in much of Europe. Climate-related changes in flood frequency are complex and depend on theflood-generatingmechanism(e.g.heavy rainfall vs snowmelt).
- Autor
- Kundze Wicz, Zbigniew W.
- Palabras Clave
- Inundaciones, Lluvia, Sequías, Cambio climático
- Idioma
- Inglés
- Documentos
- Ponencia ( 16 pag, 808 Kb )
- Presentación