Tranfaglia Giuseppe, Braca Giovanni, Monacelli Giuseppina, Biafore Mauro, Porfido Sabina and Mazzarella Adriano
The rainfall monitoring network of the Naples Department of Hydrographic and Oceanographic Service (NDHOS) was inadequate to measure the alluvial event occurred at Sarno on 5 May 1998, when a low rainfall amount of 101 mm was considered responsible for a dramatic landslide. To improve the measuring capability of this network, 50 new monitoring stations were later on added and located in such a way to increase significantly the fractal dimension of their areal distribution. The enlargement of the network allowed the correct measurement of the extreme event occurred in Naples on 15 September 2001. The paper reports also the risk of landslide phenomena (not catastrophic but however not negligible) inside the metropolitan area of Naples, frequently subjected to rock falls and to collapse of underground cavities.