The hydrogeological instability and the renaturalization of waterways
The hydrogeological instability includes all those processes that can cause soil degradation. Usually these actions are caused both by meteorological phenomena and by human activities, such as overbuilding.
The hydrogeology deals with the study of groundwater, also related to surface water.
The phenomena that include hydrogeological instability are water erosion (landslides), floods, avalanches, deforestation, the illegal building, the abandonment of high ground, the continuous excavations, the extraction of hydrocarbons and water from the subsoil, invasive interventions and not eco-sustainable on the waterways.
In Italy it is a fairly significant problem, it varies from area to area and the consequences of the process are different. The problem is widespread on the national territory, especially due to the geological conformation, determined by a complex orographic surface and by hydrographic basins of limited size.
Weather conditions can sometimes take on a dangerous character, especially if they occur with particular intensity; in fact it is possible that they can cause considerable damage to things and people. However, a distinction must be made between risks caused directly and indirectly. The former can be caused by thunderstorms, winds, fog, snow and frosts, therefore by atmospheric phenomena. Indirect risks are caused by the union of meteorological processes with aspects of the territory, linked to human activities: they concern for example heavy or abundant rains, combined with particular conditions of a territory, which can cause landslides or floods (hydrogeological or hydraulic risk). High temperatures, low humidity and strong winds, combined with the characteristics of the soil, can determine the risk of fires. Or even heavy snowfalls in the mountains, combined with significant winds and slopes can generate avalanches.
With the term of Naturalistic Engineering we refer to those techniques that are used to reduce the risk of soil erosion during consolidation works. The techniques of Naturalistic Engineering represent an excellent solution, especially for the creation or restoration of a degraded natural environment, through the use of native vegetation and the hydrogeological arrangement of the territory, the recovery of the natural habitat and the landscaping of artifacts. and infrastructure.
There-naturalization interventions they are more and more common in our country, especially in those environments where the state of alteration linked to river courses is a problem. These works are usually dealt with to secure nearby urban areas.
All the works of Naturalistic Engineering are made with natural materials such as:
plant materials such as seeds, plants and shrub species, roots and plant parts of woody plants, turf;
inert organic materials, such as timber, jute nets, straw, hay and biodegradable organic materials;
synthetic materials, which better protect the soil giving the soil greater stability, such as grids, nets and fabrics together with nylon, polyethylene and chemical adhesives;
generic inert materials, such as stones, wire, iron, galvanized nets.
When dealing with a Naturalistic Engineering operation, there are some recurring elements that are used, which differ from more traditional interventions.
It begins with the analysis of the topographic and climatic characteristics of each surface subject to intervention, the soil is then examined in relation to the chemical, physical and hydrological, and geomorphological characteristics; a phase of floristic and vegetative study follows, paying attention to the possible presence of rare botanical species and seeds, and also evaluating the biotechnical characteristics of the species themselves, their capacity and speed of growth, of adaptation to the environment, and also to the possible availability on the market.
We then move on to assessing any presence of existing infrastructures. After this first analysis we arrive at the study of the use of the new materials that will be used, with the relative selection of the plant species to be used and possible grassy sod transplants. Then the type of environmental and naturalistic reintegration is evaluated, trying to improve the area by masking the artificial elements of the work.
Among the advantages of the methods used by Naturalistic Engineering are the reduced costs for the construction and maintenance, the creation of natural habitats, the conservation and improvement of the landscape.
Among the disadvantages are the periodic and continuous maintenance, the limits of the size of interventions and the times that are not always immediate and fast.
All the operations and processes studied by the Naturalistic Engineering have the objective of protecting watercourses: rivers are not simple river channels; since the past rivers have been the seat of the birth of towns, civilizations and cities, since they are natural axes of water supply but also function as means of navigation and transport. Waterways are resources to be exploited.