A shallow layer model for heavy gas dispersion from natural sources: application and hazard assessment at Caldara di Manziana, Italy.

Several non-volcanic sources in central Italy emit a large amount of carbon dioxide (CO2). Under
stable atmospheric conditions and/or in presence of topographic depressions, the concentration of
CO2, which has a molecular mass greater than that of air, can reach high values that are lethal to
humans or animals. Several episodes of this phenomenon were recorded in central Italy and
elsewhere. In order to validate a model for the dispersion of a heavy gas and to assess the
consequent hazard, we applied and tested the code TWODEE-2, an improved version of the
established TWODEE model, which is based on a shallow layer approach that uses depth-averaged
variables to describe the flow behavior of dense gas over complex topography. We present results
for a vented CO2 release at Caldara di Manziana in central Italy. We find that the model gives
reliable results when the input quantity can be properly defined. Moreover, we show that the
model can be a useful tool for gas hazard assessment, by evaluating where and when lethal
concentrations for humans and animal are reached.Several non-volcanic sources in central Italy emit a large amount of carbon dioxide (CO2). Under
stable atmospheric conditions and/or in presence of topographic depressions, the concentration of
CO2, which has a molecular mass greater than that of air, can reach high values that are lethal to
humans or animals. Several episodes of this phenomenon were recorded in central Italy and
elsewhere. In order to validate a model for the dispersion of a heavy gas and to assess the
consequent hazard, we applied and tested the code TWODEE-2, an improved version of the
established TWODEE model, which is based on a shallow layer approach that uses depth-averaged
variables to describe the flow behavior of dense gas over complex topography. We present results
for a vented CO2 release at Caldara di Manziana in central Italy. We find that the model gives
reliable results when the input quantity can be properly defined. Moreover, we show that the
model can be a useful tool for gas hazard assessment, by evaluating where and when lethal
concentrations for humans and animal are reached.Several non-volcanic sources in central Italy emit a large amount of carbon dioxide (CO2). Under
stable atmospheric conditions and/or in presence of topographic depressions, the concentration of
CO2, which has a molecular mass greater than that of air, can reach high values that are lethal to
humans or animals. Several episodes of this phenomenon were recorded in central Italy and
elsewhere. In order to validate a model for the dispersion of a heavy gas and to assess the
consequent hazard, we applied and tested the code TWODEE-2, an improved version of the
established TWODEE model, which is based on a shallow layer approach that uses depth-averaged
variables to describe the flow behavior of dense gas over complex topography. We present results
for a vented CO2 release at Caldara di Manziana in central Italy. We find that the model gives
reliable results when the input quantity can be properly defined. Moreover, we show that the
model can be a useful tool for gas hazard assessment, by evaluating where and when lethal
concentrations for humans and animal are reached.Several non-volcanic sources in central Italy emit a large amount of carbon dioxide (CO2). Under
stable atmospheric conditions and/or in presence of topographic depressions, the concentration of
CO2, which has a molecular mass greater than that of air, can reach high values that are lethal to
humans or animals. Several episodes of this phenomenon were recorded in central Italy and
elsewhere. In order to validate a model for the dispersion of a heavy gas and to assess the
consequent hazard, we applied and tested the code TWODEE-2, an improved version of the
established TWODEE model, which is based on a shallow layer approach that uses depth-averaged
variables to describe the flow behavior of dense gas over complex topography. We present results
for a vented CO2 release at Caldara di Manziana in central Italy. We find that the model gives
reliable results when the input quantity can be properly defined. Moreover, we show that the
model can be a useful tool for gas hazard assessment, by evaluating where and when lethal
concentrations for humans and animal are reached.Several non-volcanic sources in central Italy emit a large amount of carbon dioxide (CO2). Under
stable atmospheric conditions and/or in presence of topographic depressions, the concentration of
CO2, which has a molecular mass greater than that of air, can reach high values that are lethal to
humans or animals. Several episodes of this phenomenon were recorded in central Italy and
elsewhere. In order to validate a model for the dispersion of a heavy gas and to assess the
consequent hazard, we applied and tested the code TWODEE-2, an improved version of the
established TWODEE model, which is based on a shallow layer approach that uses depth-averaged
variables to describe the flow behavior of dense gas over complex topography. We present results
for a vented CO2 release at Caldara di Manziana in central Italy. We find that the model gives
reliable results when the input quantity can be properly defined. Moreover, we show that the
model can be a useful tool for gas hazard assessment, by evaluating where and when lethal
concentrations for humans and animal are reached