LARGE ALLUVIAL FANS IN THE NORTH-CENTRAL PO PLAIN (NORTHERN ITALY)

Seventeen alluvial fans in the Po Plain, between the Ticino and Mincio Rivers, in Northern Italy were identified and studied. The research w as carried out following a semi-quantitative approach that combined di splay and analysis of altitude data, interpretation of morphometrical maps, and comparative inspection of geomorphological maps. Boundaries between fans were drawn interactively on a shaded relief image, comput ed from a 50 m resolution digital terrain model prepared interpolating 5 and 1 metre contour lines. For each fan, or for each portion making up a larger fan, geometric and morphometric criteria were computed. F an morphometric criteria were compared to the present drainage basins morphological setting. The relationship between fan area and drainage basin area shows positive allometry, with the slope of the regression line lower than that commonly proposed for both arid and humid regions .