Agricultural-forestry and hydraulic arrangements

The widespread landslide risk and hydrogeological risk of the volcanic complex Somma-Vesuvius is due to its geomorphological characteristics. Most of the phenomena occur on the north-eastern slopes, where there are very steep and incised valleys, where the alternation of soils and pyroclastic materials reach very high thicknesses and are easily mobilized by the effect of precipitation and surface flow. In addition, the high water retention of these materials increases their weight on the slope and facilitates mobilization. Phenomena of landslides can affect entire valley systems, until they reach the inhabited centres located at the mouth of the valleys, determining conditions of high hydrogeological risk.

Until a few decades ago, the territory of the Vesuvius National Park still had a strongly agricultural connotation. In order to cope with the frequent landslides on the slopes, especially on Mount Somma, farmers have learned to shape the sides of the mountain with agricultural arrangements that allow, at the same time, to obtain cultivable areas and systems to reduce the hydrogeological risk. It’s about the terracing and the “ciglionamenti”. These are differentiated by the presence in the first of a retaining wall, and in the second of embankments.

The Regi Lagni are a great work of hydraulic engineering of the Kingdom of Naples, innovative and avant-garde for the time, born for the regulation of the abundant rainwater that triggered landslides or generated marshy areas downstream. The project was entrusted, at the beginning of the 17th century, to Domenico Fontana and involved an area of about 110,000 hectares of the Piana Campana, on which the network of arrangements of the Somma-Vesuvio was later added, based on a project by the engineer Carlo Afan de Rivera, under the reign of Ferdinand I of Bourbon. Begun in 1855, intensified after the eruption of 1906, the work of regulating the waters of the Somma- Vesuvius continued until about 1936. During this period, more than 100 km of canals and 21 km of watercourses were built, equipped with numerous bridles and about 35 absorption tanks.

Always with the aim of reducing the transport of solid materials downstream, after the Great War and until 1936, extensive forestation works were undertaken.

Naturalistic engineering is a technical-naturalistic discipline that uses native live plants as building materials, alone or in combination with other traditional and non-traditional materials”. ( AIPIN)

Engineering is the operational tool capable of combining the principles of safety with the fundamental principles of environmental protection. In fact, it includes a set of techniques capable of preventing hydrogeological risk by using, as the main raw material, live plants that with their roots increase the mechanical strength of the work and allow a rapid renaturation of the area of intervention.