Abstract
Air-fall pyroclastic deposits covering Campanian mountain slopes (southern Italy) are very prone to instability under heavy and prolonged rainfall. In such a geo-hazard framework, to understand hydrological dynamics of pyroclastic mantle is a step further toward the deterministic assessment of rainfall thresholds and landslide hazard. In this research, the hydrological modelling of a pyroclastic soil mantled slope of the Sarno Mountains is proposed to assess the role of antecedent hydrological conditions on rainfall triggering debris flows. The approach is based on the finite difference modelling, from seasonal to inter-annual timescales, of unsaturated/saturated flows occurring into the pyroclastic mantle upslope of a source area of a debris flow. Modelling results were calibrated by means of field measurements achieved by a tensiometer monitoring station. Among the main results, the pressure head distribution into the pyroclastic deposits showed a dominant unsaturated condition and a relevant seasonal variation extending below the root zone and down to the bedrock interface, about 4 m deep. This hydrological regime is attributable both to the distinctive water retention properties of pyroclastic soils and to the existence of a deciduous forest, which concentrates water losses due to evapotranspiration during the dry season. This behavior highlights the remarkable role of antecedent hydrological conditions as a not negligible predisposing factor to instability during short and heavy rainstorms.
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References
Allen RG, Pereira LS, Raes D, Smith M (1998) Crop evapotranspiration. Guidelines for computing crop water requirements, Food and Agriculture Organization of the United Nations, Irrigation and Drainage Paper, 56, p. 328
Cepeda J, Höeg K, Nadim F (2010) Landslide-triggering rainfall thresholds: a conceptual framework. Q J Eng Geol Hydrogeol 43:69–84
Damiano E, Olivares L, Picarelli L (2012) Steep-slope monitoring in unsaturated pyroclastic soils. Eng Geol 137–138:1–12
De Vita P, Piscopo V (2002) Influences of hydrological and hydrogeological conditions on debris flows in peri-Vesuvian hillslopes. Nat Hazard Syst Sci 2:1–9
De Vita P, Napolitano E, Godt J, Baum R (2013) Deterministic estimation of hydrological thresholds for shallow landslide initiation and slope stability models: case study from the Somma–Vesuvius area of southern Italy. Landslides 10:713–728
Fiorillo F, Wilson RC (2004) Rainfall induced debris flows in pyroclastic deposits, Campania (southern Italy). Eng Geol 75:263–289
Fusco F, De Vita P, Napolitano E, Allocca V, Manna F (2013) Monitoring the soil suction regime of landslide-prone ash-fall pyroclastic deposits covering slopes in the Sarno area (Campania - southern Italy). Rendiconti Online Società Geologica Italiana 24:146–148
Godt JW, McKenna JP (2008) Numerical modelling of rainfall thresholds for shallow landsliding in the Seattle, Washington, area. Reviews in engineering geology. Geol Soc Am 20:121–135
Guadagno FM, Forte R, Revellino P, Fiorillo F, Focareta M (2005) Some aspects of the initiation of debris avalanches in the Campania Region: the role of morphological slope discontinuities and the development of failure. Geomorphology 66:237–254
Guzzetti F, Peruccacci S, Rossi M, Stark CP (2007) Rainfall thresholds for the initiation of landslides in central and southern Europe. Meteorol Atmos Phys 98:239–267
Hsieh PA, Wingle W, Healy RW (2000) VS2DI: A graphical software package for simulating fluid flow & solute or energy transport in variably saturated porous media, U.S. Geological Survey, Water-Resources Invest. Report, 9-4130, p. 20
Sorbino G (2005) International symposium on advanced experimental unsaturated soil mechanics, Trento, Italy, 27–29 June 2005. In: Tarantino R (ed) Numerical modelling of soil suction measurements in pyroclastic soils. Taylor & Francis Group, London, pp 541–547
Thornthwaite CW (1948) An approach toward a rational classification of climate. Geograph Rev 38:55–94
USDA (2010) Keys to soil taxonomy, 11th edn. USDA-Nat, Res. Cons. Service, p 346
Acknowledgments
This research was supported by the PRIN Project (2010-2011) “Time-Space prediction of high impact landslides under changing precipitation regimes” funded by the Ministry for Education, University and Research (MIUR-Italy).
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Napolitano, E., De Vita, P., Fusco, F., Allocca, V., Manna, F. (2015). Long-Term Hydrological Modelling of Pyroclastic Soil Mantled Slopes for Assessing Rainfall Thresholds Triggering Debris Flows: The Case of the Sarno Mountains (Campania—Southern Italy). In: Lollino, G., et al. Engineering Geology for Society and Territory - Volume 2. Springer, Cham. https://doi.org/10.1007/978-3-319-09057-3_278
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DOI: https://doi.org/10.1007/978-3-319-09057-3_278
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