The present work summarizes the knowledge of the effects of water utilization and of climate changes on the Vulsino aquifer and on the Bolsena Lake water resources (Central Italy), that are essential for water management and for environmental sustainability. The volcanic aquifer is made up of alternated lava and pyroclastic deposits, laid over low permeability lithotypes composed of shallow marine to continental clays, sands, conglomerates and flysch formations. The hydrogeological basin of the Bolsena Lake is about 350 km2 and is larger than the catchment basin (about 273 km2). The Lake is located in a region that seems to be already undergoing the effects of the so-called “Climatic Change”. In order to investigate the impact of climatic variations on the lake regime a monthly climatic analysis was made. Trends in rainfall are consistent with those of many other localities of Central Italy. The reduction in rainfall coupled with the amount of water pumped from wells produced a reduction in the discharge in the outlet of Bolsena Lake. A monthly lake level simulation model was applied to the Bolsena Lake making some scenarios for the next decades. The scenarios built using the model indicate that for a moderate rainfall decrease up to the 10%, the minimum vital flow (MVF) to the outlet could be supplied only if a sensible reduction of the withdrawals were to be applied. For a rainfall decrease higher than 10% the lake would become a closed lake, even if the withdrawals were reduced to zero. This is in agreement with the fact that around 1000 B.C. the level of the Lake was about 5 meters lower than today.
Impact of climatic change on the management of complex systems: the case of the Bolsena Lake and its aquifer (Central Italy)
DI MATTEO, Lucio;DRAGONI, Valter Ulderico;GIONTELLA, CECILIA;MELILLO, MASSIMO
2010
Abstract
The present work summarizes the knowledge of the effects of water utilization and of climate changes on the Vulsino aquifer and on the Bolsena Lake water resources (Central Italy), that are essential for water management and for environmental sustainability. The volcanic aquifer is made up of alternated lava and pyroclastic deposits, laid over low permeability lithotypes composed of shallow marine to continental clays, sands, conglomerates and flysch formations. The hydrogeological basin of the Bolsena Lake is about 350 km2 and is larger than the catchment basin (about 273 km2). The Lake is located in a region that seems to be already undergoing the effects of the so-called “Climatic Change”. In order to investigate the impact of climatic variations on the lake regime a monthly climatic analysis was made. Trends in rainfall are consistent with those of many other localities of Central Italy. The reduction in rainfall coupled with the amount of water pumped from wells produced a reduction in the discharge in the outlet of Bolsena Lake. A monthly lake level simulation model was applied to the Bolsena Lake making some scenarios for the next decades. The scenarios built using the model indicate that for a moderate rainfall decrease up to the 10%, the minimum vital flow (MVF) to the outlet could be supplied only if a sensible reduction of the withdrawals were to be applied. For a rainfall decrease higher than 10% the lake would become a closed lake, even if the withdrawals were reduced to zero. This is in agreement with the fact that around 1000 B.C. the level of the Lake was about 5 meters lower than today.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
