“Venice Province Soil Information System and soil management”

The authors present a study conducted in the northeast of the Province of Venice, in the area falling between the Sile and Livenza rivers, where depressions with elevations below the average sea level alternate with hillocks of fluvial origin. The evolution of this territory has been influenced by numerous environmental factors such as periodic flooding, changes in sea level and the progressive phenomenon of subsidence. Over time, the complexity of the situation has been further compounded by the action of the rivers that presently flow through the territory itself: via aerial photogrametry and remote sensing it is possible to trace their former courses, associated with repeated processes of erosion and sedimentation that have conspicuously modelled the surface of this plain area lying in proximity to the coastline. Added to these factors is the impact of numerous human interventions aimed at diverting the main watercourses (Piave, Livenza) and reclaiming wetland areas. The study involved a sequence of stages. First of all the territory was divided into homogenous Landscape Units, coded according to the criteria defined in the catalogue of landscapes of the Venetian plain; said units were identified on the basis of GIS ArcView information technology, using the Geomorphological Map of the provincial - mainland territory (DOGE project) and the microrelief map and digital models derived therefrom as the basic mapping resources. The soil and geological maps already available were used for purposes of thematic verification and calibration. Pedological data derived from georeferenced field surveys were processed and soils were classified according to profile type and area distribution of several physical and chemical properties. This made it possible to define associations and relations among the soils present, such as to provide a basis for computer-aided soil mapping.