**7. Estimating hazard and risk at Somma-Vesuvius**

The last eruption at Vesuvius took place in 1944. After this date, the long lasting quiescence period encouraged the strong urbanization in perivolcanic areas. In the first decades of the twentieth century, when activity at Vesuvius was almost continuous, no significant increase in population rate was recorded along the Vesuvius coastline (**Figure 29**). In the last five decades, on the contrary, a very strong increase in population rate was recorded. In the coastal

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**Figure 29.**

*The Somma-Vesuvius Activity with a Focus to the AD 79 Eruption: Hazard and Risk*

area of Vesuvius, the population strongly increased up to 1980, when the large towns, already congested by traffic and degradation, become saturated (**Figure 30**). In 1930, inhabited areas were far from each other and located along the main municipal roads. In 1960, inhabited areas expanded and industrial sites grew in agricultural areas. At present, both inhabited and industrial

*an increase of the inhabitants. Data are taken from Italian newspapers.*

*Topographic maps of Torre del Greco by the following age: 1876, 1906, and 1936. This range does not represent* 

*DOI: http://dx.doi.org/10.5772/intechopen.89989*

*The Somma-Vesuvius Activity with a Focus to the AD 79 Eruption: Hazard and Risk DOI: http://dx.doi.org/10.5772/intechopen.89989*

#### **Figure 29.**

*Forecasting Volcanic Eruptions*

**Figure 27.**

**Figure 28.**

*1944 lava flow invaded the San Sebastiano al Vesuvio.*

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together with a continuous fumarolic activity at the crater, remind people that,

The last eruption at Vesuvius took place in 1944. After this date, the long lasting quiescence period encouraged the strong urbanization in perivolcanic areas. In the first decades of the twentieth century, when activity at Vesuvius was almost continuous, no significant increase in population rate was recorded along the Vesuvius coastline (**Figure 29**). In the last five decades, on the contrary, a very strong increase in population rate was recorded. In the coastal

although dormant, the volcano is still active (**Figure 28**).

*Vesuvius crater after the 1944 explosive eruption.*

**7. Estimating hazard and risk at Somma-Vesuvius**

*Topographic maps of Torre del Greco by the following age: 1876, 1906, and 1936. This range does not represent an increase of the inhabitants. Data are taken from Italian newspapers.*

area of Vesuvius, the population strongly increased up to 1980, when the large towns, already congested by traffic and degradation, become saturated (**Figure 30**). In 1930, inhabited areas were far from each other and located along the main municipal roads. In 1960, inhabited areas expanded and industrial sites grew in agricultural areas. At present, both inhabited and industrial

#### **Figure 30.**

*1996 topographic map and a diagram pointing the increase of population in recent years (1996, unpublished data). From 1996 up to now, the increase of population has not stopped.*

sites cover the whole territory, and agricultural areas are much reduced. A hazard map was obtained encompassing both the fall products possible hazard and the pyroclastic density current areas (drawn after Protezione Civile Italiana) (**Figure 31**).
