Application of the Computerised Cartography to the Territory Management: The Geomorphological Map of Palaeolandslides in the Velino River Valley (Central Apennines, Italy)

摘要

The geomorphological cartography explained in this work is the result of a process of synthesis resulting from detailed geological and geomorphological and hydrogeological researches and from numerous land surveys carried out during the past ten years. The choice of the study area can be explained by the presence of important and complex phenomena involving the upper course of the Velino river, such as palaeo-landslides, mass-movements and debris flows, subsidence phenomena, etc. In particular, these phenomena involve several towns (Posta, Micigliano, Sigillo, Villa Camponeschi), as well as a fundamental route (State Road 4), following the ancient consular road, named Salaria, roman in age. The informations deriving from the land surveys has been integrated and controlled by photo-interpretation (related at 1982 and 2000 aero-photographs). The result has been implemented by the 2006 cartography, which was obtained from the ortho-rectified images, subject to a "spreading" over the digital model of the terrain that was obtained from the regional topographical cartography at a scale of 1:10,000, promoted by the Lazio Region. Even if they have well-known limits of representation that derive from the approximate restoration of the basic regional maps that were realised in the 1980s, the latter represent a very up-to-date control instrument, depending on a critical analysis of the information. All the data have been computerised by exploiting the tools made available by the ESRI platform, through the development of an innovative logical pattern for the geomorphology, since the aforesaid data were treated by considering forms, processes and deposits on the basis of the prevailing morphogenetic agent. In this way, the problems deriving from the contiguity and superimposition of several polygonal forms in logical contrast and topological conflict have been overcome. Hopefully, several representational limits will be overcome once the set-up valid for the published printing has been made ready, since the instruments currently available have several technical limitations in the raster process and, in spite of the information present is correct, it does not yet respect several qualitative standards typical of Italian graphic representation. Several graphic improvements typical of the Italian publishing language and cartographic tradition will be the topic of the subsequent phase. Despite Italian tradition imposes extreme attention on the graphic aspect, it is very important to note that the territorial computer-related systems facilitate an analysis of the coverings, depending on the substrate on which they are imposed, and make it possible to define a model according to which the forms, processes and deposits evolve over time, infact the whole upper valley of the Velino river is annually subjected to deep changes due to the high energy of relief and extreme weather conditions: knowledge and proper analysis of these phenomena can contribute significantly to the right land management, giving due importance to the prevention and the screening to be daily carried out.