Seite - 585 - in Book of Full Papers - Symposium Hydro Engineering

usually the coldest month, reaching a monthly average temperature of 3.7°C, with average maximum and minimum monthly means of 11° C and -2.3°C respectively. For the Huantsán glacier, a reduction of the ice masses of 6.4 % was estimated between 1988 and 2008 ([7] and [8]). Due to this reduction of the glacier, the location and corresponding volume of 18 different ice blocks were identified on site (see Fig. 2), which represent a potential risk of detachment. Based on satellite data (ALOS and Sentinel 2b) the mean slopes and topographical conditions were analyzed for these blocks. The determined mean slope for the 18 blocks is 31 ° - maximum slopes reach 65 ° (see Fig. 3). This is also in accordance with the findings from [9], where different glaciers of the Cordillera Blanca were studied with respect of air temperature and slopes. According to the findings from [10], the identified glacier blocks represent a potential threat based on the mean annual temperature, their volumes and the identified slopes (see Fig. 4). Based on these results, the risk of a detachment is eminent and thus consequences of an ice block detachment were analyzed. Fig. 4 Relation between average slope and volume of large ice avalanches worldwide (left) & mean annual air temperature to critical slope (right) – comparison of investigation data with findings from [10] (range of temperature from [11]) Relation entre la pente moyenne et le volume des grandes avalanches de glace dans le monde (gauche) & température moyenne de l'air contre la pente critique (droite) - comparaison des resultat de (9) (variété de température de [10]) 3. SIMULATION OF THE IMPACTING ICE BLOCKS 3.1. PRESELECTION OF THE SIMULATED ICE BLOCKS As it can be seen from Fig. 2, some of the identified 18 blocks have similar characteristics in terms of their elevation and fall trajectory. A preliminary analysis based on the methodology described in Chapter 3 of [12] identified the blocks generating the most unfavorable effects. This methodology also was applied to the event occurred in 2010, where a large block of ice and rocks of 450 000 m3 585