Leica Geosystems TruStory Monitoring to Secure an Area With Hydrogeological Instability

Scope/Objective Automatic and continuous monitoring of a mountain slope affected by hydrogeological instability

Customer/Institution The Region of Valle d’Aosta

Challenge Continuous monitoring of any movements in the area for activation of the Civil Protection plan

Date July 2009 - ongoing

Location Valle d’Aosta, Italy

The Aosta Valley (Valle d‘Aosta) Since 2000 the Region of Valle is a mountainous semi-auto- d’Aosta and the department for nomous region in north-western “Inspectorate for public works, soil Italy. It is bordered by Rhône- conservation and water resources Alpes, France to the west, – Geological Service” have carried Valais, Switzerland to the north out a series of surveys in order to Project Summary and the region of Piedmont to gain in-depth knowledge on the Instruments the south and east. With an instability and to understand its Leica TCA2003 Total Station area of 3,263 km2 (1,260 sq dynamics. Leica NIVEL210 Tilt Sensor mi) and a popu-lation of about Leica GMX902 GG 130,000, it is the smallest and As a result, today this area is moni- Leica AS10 least densely populated region tored 24 hours, 7 days a week with Leica GMX901 with communication box Leica Geosystems Monitoring prisms of Italy. It is an Alpine valley a fully automatic and integrated Master Unit PC that, with its side valleys, deformation monitoring system. Software includes the Italian slopes of The system combines geodetic Leica GeoMoS Monitor the Mont Blanc (Monte Bianco), and geotechnical instrumentation Leica GNSS Spider Monte Rosa and the Matterhorn. as well as ground radar measure- SystemAnywhere (data synchronisa- ments. tion & calculations) and Analysis (data Some areas are affected by slope Based on the surveying results of view) instability called DGPV (Deep-seated the last years and the importance Communication Gravitational Slope). The main of the regions, dedicated monitoring Wireless LAN State Road 26 section accessing points on the slopes have been GSM/GPRS the Mont Blanc Tunnel, as well as selected for automatic deformation Office the districts of Entrev and Palud are monitoring and stability analysis. Analysis influenced. About 30 monitoring prism and 5 reference prisms are installed. of the buffer battery on site. The These prisms are measured with a power system consists of solar Benefits Leica TCA2003 total station every panels and a methanol tank system. - Study of landslide dynamics Protecting the safety of the hour. The total station is installed A special electronic device controls population in a stable area with a pillar secured automatically and intelligently the - Analysis and study of an to a rock on site. In addition, a correct power input to the monitoring efficient integrated approach dual axis inclination sensor Leica equipment between the solar panel to multisensor monitoring Nivel210 is installed to verify the and the methanol tank system. stability of the station with an independent sensor. Near to the The complete automatic monitoring located in the headquarters of Leica TCA2003 total station, a system is left unattended in the the customer. This SystemAnywhere separate GMX902 GG receiver with remote environment of the Aosta retrieves the pure raw data and Leica AS10 antenna is installed. Valley. The total station and the then automatically computes the Also, several Leica GMX901 have Leica GMX receivers are managed total station corrections as been installed with co-located by Leica GeoMoS and Leica GNSS orientation, free station, ppm etc. prisms that record data with 1Hz. Spider, which are installed on a Total station and GNSS baselines The monitoring prisms and the master computer (embedded in- are combined and limit checks Leica GMX901 are installed over dustrial PC), located inside the total computed. the slope to monitor critical posi- station measurement hut. The tions. total station, the Leica GMX902 GG In case the three different set limit sensor and the Leica Nivel are thresholds are exceeded, the Commonly for alpine valleys, human connected via cable to the master reponsible staff member in charge access to the monitoring sensors is computer and the GMX901 sensors is informed and the required actions very limited. All installed equipment are connected via 5GHz wireless are taken to ensure the safety in requires a reliable and autonomous link. the Aosta Valley. energy source that guarantees that As a result, the monitoring system the equipment works properly. Due The acquired raw data from Leica includes two independent geodetic to the amount of snow and the GeoMoS and Leica GNSS Spider is measuring sensors, total station reduced solar irradiation during downloaded from the monitoring and GNSS data, that increase the winter months, a combined power site, with the software called reliability of the system. The data supply system was installed for SystemAnywhere, to another dedi- is correlated for further evaluation. continuous power and recharging cated monitoring system computer This autonomous monitoring system is beneficial for the Aosta Valley, as continuous monitoring data is collected and analysed providing detailed deformation information. In addition, messages are sent to notify the required personnel of exceeded limit levels providing advance warning of possible problems and protecting the safety of the local population.

Leica Geosystems AG Heinrich-Wild-Strasse CH-9435 Heerbrugg Switzerland Phone +41 71 727 31 31 www.leica-geosystems.com