The debris-flows monitoring system of Acquabona torrent (Cortina d’Ampezzo, BeLluno, Italy)

Abstract

The article presents a debris-flow monitoring system installed in the site of Acquabona near Cortina d’Ampezzo, in the province of Belluno, Italy.The site, whose activity is almost annual, was equipped in the second half of the 90s, with the aim of characterizing the phase of initiation, flow and deposition of debris- flows typical of the Dolomitic areas. Three measuring stations were been realized. The power of the equipment was provided by solar panels. The field data were stored on site and recovered through inspections to the station.The monitoring activity has proven to be, over the years, of great dif culty as a result, firstly, of the need for frequent visits to the site, sometimes long after the events occurrence, and, secondly, of the morphological changes taking place in the water course under study. In particular it was observed a progressive regression of the deposition area that was and still is affecting the two downstream stations.The monitoring system has been, therefore, redesigned taking into account the need to move old downstream stations at a higher elevation and the will to remotely control the activity of the basin. At the moment two new stations have been realized. The first one is a weather station that collects rain, wind, temperature and humidity data. It is located further upstream than the previous upstream station and in a more apical position in the basin, to better characterize initial conditions that trigger debris flows. The second one has been realized in the flowing zone, near the deposition area. It has been equipped with an ultrasonic level meter, a video-camera served by a system of night lighting and a tipping bucket rain gauge. Geophones have been used for the activation of the monitoring system and for measuring front velocities.Substantial changes have been introduced, in comparison with the previous installation, in the power supply of downstream station that will be reached by the main electricity grid. The power supply of the upstream weather station will be, instead, ensured by solar panels. The data coming from the two stations are collected at the downstream station (a radio link connects the upstream meteorological station with the downstream station) and are available for the download from the Department of Geosciences of Padua via mobile Internet.