The past Friday, October 8th, fieldwork activities were carried out in the Passeier Valley. Like in the previous two field trips (First field trip – June 17th and Field trip campaign July 26th – 30th), the primary goals were to take soil samples and execute the DCPT (Dynamic Cone Penetration Test) to determine hydrological and geotechnical soil properties. This time there was no need for digging a soil pit, as the soil samples could be taken from a large old landslide scarp. According to the owner of the field, this landslide occurred due to an earthquake around 2000.  However, by checking the USGS database of past earthquakes, it was found that the landslide likely correlates to a relatively large earthquake that occurred on July 17^th of 2001, with a magnitude of 4.7 and its epicenter in the middle of the Passeier Valley (https://www.volcanodiscovery.com/earthquakes/quake-info/4826702/mag4quake-Jul-17-2001-northern-Italy.html)

On September 17th, Stefan Steger from Eurac Research participated in the Civil Protect 2021 event to present Proslide activities to the public and local decision makers. The session was entitled Online inventory of mass movements (fierabolzano.it). His presentation was entitled Analisi dei movimenti di massa in Provincia di Bolzano and it was presented during the session Inventario on-line dei movimenti di massa: quali sono i vantaggi per questa amministrazione?

Screenshot of the program event.

During the week of July 26^th  – 30^th, fieldwork in the Passeier Valley was conducted with the main goal of data collection. The collected information corresponds to soil samples and the execution of the Dynamic Cone Penetration Test (DCPT). Laboratory analysis will be carried out from the collected data to classify the soil material and extract hydrological and geotechnical parameters such as soil density, water content, hydraulic conductivity, cohesion, and friction angle, which are essential inputs for the physically-based modeling.

The fieldwork in the five days was mainly divided into two stages. The first one consisted of digging a soil pit (with dimensions of 1m x 1m x 1m) at each previously selected location to have a clean soil profile for descriptions and sampling. Out of the soil profile, two buckets of material and several ring-shaped samples for laboratory analysis were taken at different depths to have a suitable representation of the soil profile. Furthermore, the second stage involved the execution of the DCPT to determine the soil depth and have a general overview of the soil structure. All the sampling and tests were done after discussing and getting permission from the landowners.

Lastly, the fieldwork team was very grateful for the friendliness of the farmers in the Passeier valley. The conversations with them gave great detail of information on the local problems with landslides and of course, their corporation in allowing the samples to be taken from their fields, was also very thankful.

On June 17^th, fieldwork activities were carried out in the Passeier valley. The field trip had several goals. The main one was to get familiar with the study area chosen for the physically-based approach of the landslide hazard assessment. Besides, getting the first soil samples to determine the hydrological and geotechnical parameters of the soil and testing out the equipment that will be used during the next field campaigns at the end of July.

The first stop was a meadow near Sankt Martin in Passeier on the south-facing hillside. After a very informative conversation with the landowner about previous landslides in the area, a Dynamic Cone Penetration Test (DCPT) was executed. The information from the DCPT can be used to determine the regolith depth, one of the most important parameters in the physically-based model. At one of the three test sites for the DCPT, a soil pit was dug to assess the soil structure and take soil samples from several depths.

The second stop was on the north-facing hillside, between Quellenhof and Neuhaus. A Terrestrial Laser Scanning (TLS) acquisition was performed. This acquisition will be used to construct a Digital Elevation Model (DEM) with a high resolution. This DEM can be used to find signs of previous landslide occurrences among all its potential uses. It is known that several landslides occurred at the site in 2016; nevertheless, since the latest DEM is from 2014, this cannot be used for the 2016 event. Therefore, the DEM generated from the TLS will cover this gap.