Deciphering meteorological influencing factors for Alpine rockfalls: a case study in Aosta Valley

Abstract This study exploited the historical rockfall inventory and meteorological stations database of Mont Cervin Emilius Mountain Communities (Aosta Valley, northern Italy) to decipher relationships between climate processes, typical mountain environments phenomena. The period from 1990 2018 was selected as reference perform analysis. Climate processes were translated into four indices, namely short-term rainfall (STR), effective water inputs (EWI, including both snow melting), wet dry episodes (WD) freeze-thaw cycles (FT). comparison indices values at each occurrence statistical distributions describing whole dataset allowed define not ordinary climatic conditions for index their influence on occurrence. Most events analysed (>95% out 136) occurred in correspondence defined one or a combination indices. rockfalls showed seasonality. In spring, most resulted be connected FT (70%) while autumn EWI (49%). relative seasonal importance WD reached its maximum summer with 23% related this alone. Based these results, different strategies empirical critical thresholds explored, order make them valid area. A preliminary exploratory analysis high temperatures temperature gradients carried some summertime rockfalls, correlated other investigated presented approach is exportable neighbouring regions, given availability dated dataset, could adapted include processes.