Mapping the earthquake-induced landslide hazard around the main oil pipeline network of the Agri Valley (Basilicata, southern Italy) by means of two GIS-based modelling approaches

Abstract

This study presents a first-level spatial assessment of the susceptibility to earthquake-induced landslides in the seismic area of the Agri Valley (Basilicata Region, southern Italy), which hosts the largest onshore oilfield and oil/gas extraction and pre-treatment plant in Europe and is the starting point of the 136-km-long pipeline that transports the plant’s products to the refinery located in Taranto, on the Ionian seacoast. Two methodologies derived from the ones proposed by Newmark (Geotechnique 15(2):139–159, 1965) and Rapolla et al. (Eng Geol 114:10–25, 2010, Nat Hazards 61:115–126, 2012. doi: 10.1007/s11069-011-9790-z), based on different modelling approaches, were implemented using the available geographic information system tools, which allowed a very effective exploitation of the two models capability for regional zoning of the earthquake-induced landslide hazard. Subsequently, the results obtained from the two models were compared by both visual evaluation of thematic products and statistical correlation analysis of quantitative indices, such as the Safety Index based on the Newmark’s approach and the Susceptibility Index from Rapolla’s model. The comparison showed a general agreement in highlighting the most critical areas. However, some slight differences between the two models’ results were observed, especially where rock materials and steep slopes are prevailing.