Soil and territory

The Soil is a non-renewable resource in the middle of a system of relations among the different actions of people and the natural cycles that ensure well-being of humans.

The dynamics of urbanization and the gradually expansion of urban areas in Italy produce a strong acceleration of agricultural or natural soil consumption processes. In many cases the ground has been covered with waterproof materials, one of the most evident way of degradation and soil consumption. In these cases, the territory and landscape transformation is practically irreversible that has a strong impact on the agricultural fertile soil, putting at risk the biodiversity, increasing the danger  of flooding and reduction of water resources, and finally  contributing to global warming.
In order to provide an updated  of this phenomena, ISPRA has prepared since some years a network of monitoring of land use to provide brief information and specific indicators for the assessment of the event, estimating at national level and municipal areas the value of consumed surface and its evolution over time and producing in 2015, the first national map of soil consumption at very high resolution.
With the objective of representing the expansion processes are presented indicators of diffusion, density, dispersion and sprawl (increase of built area compared to the population variation), to describe the state of a city fragmentation, the different urbanization levels and the dynamic process of mismatch between the increase of the population and territorial growth.
The conditions of urbanization of the territory and land use are also important for flood events because they can contribute, together with the geological, geomorphological and climatic conditions of the territory, to determine the effects, in terms of damage, of intense meteorological events (short or long-duration rainfall events). The progressive artificiality of the territory has changed the characteristics of the network of natural drainage, by altering the level of soils permeability, the removal of floodplain areas (with artifacts in river areas), the narrowing of sections of drainage and forced canalization for the natural stream bed. The large urban centers, also for their strategic position along river basins, are strongly interested by the effects of the intense meteorological events with a constant growth over time. Italy is also particularly exposed to landslides. In urban areas, in addition to rainfall an important factor for landslide triggering is represented by human activities, such as road cut, excavations, overloads, cavities, leakage from the water or sewer system. The landslides in areas densely populated determine high risk events, because even small-size phenomena can cause victims and remarkable damages.
Another cause of environmental degradation and pressure factor against the soil resource is the minerals extraction that heavily influences the consumption of non-renewable resources, the soil loss, the landscape, with possible hydrological and hydrographic alterations and instability phenomena.  Often the urbanization has concerned also the areas characterized by the presence of active fault, that means faults able to  produce breakages and deformations on the soil surface or close to it.   In Italy, although it is not a rare event, the danger from surface faulting has not find  an adequate consideration in the anti-seismic regulations at national level. Currently, there are projects to developed guidelines to support the regional legislation in the matter of seismic micro-zoning.
A frame of the geology and geological hazard (Geohazard) of some Italian cities is presented based on  data deriving from the national geological cartography project at scale 1: 50,000 (CARG Project) which illustrates the geological setting of the territory through the making of geological maps. This tool allows to identify the parts of the city significantly affected by natural hazards and the main critical issues  related to them, that in the case of floods, volcanic eruptions and earthquakes, can be originated from zones even very far from urbanized areas. The relationship with the planning tools is faced through an analysis of the new tools that guide the transformation of the territory, with particular attention to the references to the application of the Strategic Environmental Assessment (SEA)