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)

Abstract. On 15–16 December 1999, heavy rainfall severely stroke Campania region (southern Italy), triggering numerous debris flows on the slopes of the San Martino Valle Caudina-Cervinara area. Soil slips originated within the weathered volcaniclastic mantle of soil cover overlying the carbonate skeleton of the massif. Debris slides turned into fast flowing mixtures of matrix and large blocks, downslope eroding the soil cover and increasing their original volume. At the base of the slopes, debris flows impacted on the urban areas, causing victims and severe destruction (Vittori et al., 2000). Starting from a recent study on landslide risk conditions in Campania, carried out by the Regional Authority (PAI –Hydrogeological setting plan, in press), an evaluation of the debris-flow susceptibility has been performed for selected areas of the above mentioned villages. According to that study, such zones would be in fact characterised by the highest risk levels within the administrative boundaries of the same villages ("HR-zones"). Our susceptibility analysis has been performed by applying SCIDDICA S3–hex – a hexagonal Cellular Automata model (von Neumann, 1966), specifically developed for simulating the spatial evolution of debris flows (Iovine et al., 2002). In order to apply the model to a given study area, detailed topographic data and a map of the erodable soil cover overlying the bedrock of the massif must be provided (as input matrices); moreover, extent and location of landslide source must also be given. Real landslides, selected among those triggered on winter 1999, have first been utilised for calibrating SCIDDICA S3–hex and for defining "optimal" values for parameters. Calibration has been carried out with a GIS tool, by quantitatively comparing simulations with actual cases: optimal values correspond to best simulations. Through geological evaluations, source locations of new phenomena have then been hypothesised within the HR-zones. Initial volume for these new cases has been estimated by considering the actual statistics of the 1999 landslides. Finally, by merging the results of simulations, a deterministic susceptibility zonation of the considered area has been obtained. In this paper, aiming at illustrating the potential for debris-flow hazard analyses of the model SCIDDICA S3–hex, a methodological example of susceptibility zonation of the Vallicelle HR-zone is presented.

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Long-term continuous monitoring of the dissolved CO2 performed by using a new device in groundwater of the Mt. Etna (southern Italy)

Water Research ◽

10.1016/j.watres.2011.03.028 ◽

2011 ◽

Vol 45 (9) ◽

pp. 3005-3011 ◽

Cited By ~ 9

Author(s):

Sofia De Gregorio ◽

Marco Camarda ◽

Manfredi Longo ◽

Santo Cappuzzo ◽

Gaetano Giudice ◽

...

Keyword(s):

Continuous Monitoring ◽

Southern Italy ◽

New Device ◽

Mt Etna

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Uncertainty in debris flow rainfall thresholds

10.5194/egusphere-egu21-15175 ◽

2021 ◽

Author(s):

Matteo Berti ◽

Alessandro Simoni

Keyword(s):

Debris Flow ◽

Debris Flows ◽

Measurement Errors ◽

Critical Conditions ◽

Model Parameters ◽

Average Intensity ◽

Rainfall Thresholds ◽

Sources Of Uncertainty ◽

Time Space ◽

Physically Based

Rainfall is the most significant factor for debris flows triggering. Water is needed to saturate the soil, initiate the sediment motion (regardless of the mobilization mechanism) and transform the solid debris into a fluid mass that can move rapidly downslope. This water is commonly provided by rainfall or rainfall and snowmelt. Consequently, most warning systems rely on the use of rainfall thresholds to predict debris flow occurrence. Debris flows thresholds are usually empirically-derived from the rainfall records that caused past debris flows in a certain area, using a combination of selected precipitation measurements (such as event rainfall P, duration D, or average intensity I) that describe critical rainfall conditions. Recent years have also seen a growing interest in the use of coupled hydrological and slope stability models to derive physically-based thresholds for shallow landslide initiation.In both cases, rainfall thresholds are affected by significant uncertainty. Sources of uncertainty include: measurement errors; spatial variability of the rainfall field; incomplete or uncertain debris flow inventory; subjective definition of the &#8220;rainfall event&#8221;; use of subjective criteria to define the critical conditions; uncertainty in model parameters (for physically-based approaches). Rainfall measurement is widely recognized as a main source of uncertainty due to the extreme time-space variability that characterize intense rainfall events in mountain areas. However, significant errors can also arise by inaccurate information reported in landslide inventories on the timing of debris flows, or by the criterion used to define triggering intensities.This study analyzes the common sources of uncertainty associated to rainfall thresholds for debris flow occurrence and discusses different methods to quantify them. First, we give an overview of the various approaches used in the literature to measure the uncertainty caused by random errors or procedural defects. These approaches are then applied to debris flows using real data collected in the Dolomites (Northen Alps, Itay), in order to estimate the variabilty of each single factor (precipitation, triggering timing, triggering intensity..). Individual uncertainties are then combined to obtain the overall uncertain of the rainfall threshold, which can be calculated using the classical method of &#8220;summation in quadrature&#8221; or a more effective approach based on Monte Carlo simulations. The uncertainty budget allows to identify the biggest contributors to the final variability and it is also useful to understand if this variability can be reduced to make our thresholds more precise.&#160;

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Sedimentary facies on the rises and slopes of passive continental margins

Philosophical Transactions of the Royal Society of London. Series A, Mathematical and Physical Sciences ◽

10.1098/rsta.1980.0023 ◽

1980 ◽

Vol 294 (1409) ◽

pp. 169-176 ◽

Cited By ~ 1

Keyword(s):

Sediment Transport ◽

Debris Flows ◽

Thermohaline Circulation ◽

Dominant Role ◽

Sedimentary Facies ◽

Turbidity Currents ◽

Continental Margins ◽

Passive Margins ◽

New Evidence

JOIDES drilling results provide new evidence concerning facies patterns on evolving passive margins that strengthens and extends hypotheses constructed from studies of morphology, seismic reflexion data and shallow samples on modern margins, and from field geologic studies of uplifted ancient margins. On the slopes and rise, gravity-controlled mechanisms - turbidity currents, debris flows, slides and the like - play the dominant role in sediment transport over the long term, but when clastic supplies are reduced, as for example during rapid transgressions, then oceanic sedimentation and the effects of thermohaline circulation become important. Sedimentary facies models used as the basis of unravelling tectonic complexities of some deformed margins, for example in the Mesozoic Tethys, may be too simplistic in the light of available data from modern continental margins.

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Attributing the hydrological impact of different land use types and their long-term dynamics through combining parsimonious hydrological modelling, alteration analysis and PLSR analysis

The Science of The Total Environment ◽

10.1016/j.scitotenv.2019.01.085 ◽

2019 ◽

Vol 660 ◽

pp. 1155-1167 ◽

Cited By ~ 13

Author(s):

T.G. Gebremicael ◽

Y.A. Mohamed ◽

P. Van der Zaag

Keyword(s):

Land Use ◽

Hydrological Modelling ◽

Land Use Types ◽

Hydrological Impact

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Hominin responses to environmental changes during the Middle Pleistocene in central and southern Italy

Climate of the Past ◽

10.5194/cp-9-687-2013 ◽

2013 ◽

Vol 9 (2) ◽

pp. 687-697 ◽

Cited By ~ 21

Author(s):

R. Orain ◽

V. Lebreton ◽

E. Russo Ermolli ◽

A.-M. Sémah ◽

S. Nomade ◽

...

Keyword(s):

Western Europe ◽

Southern Italy ◽

Environmental Changes ◽

Global Climate ◽

Middle Pleistocene ◽

Faunal Remains ◽

Vegetation Dynamic ◽

Local Climate ◽

Global Climate Changes

Abstract. The palaeobotanical record of early Palaeolithic sites from Western Europe indicates that hominins settled in different kinds of environments. During the "mid-Pleistocene transition (MPT)", from about 1 to 0.6 Ma, the transition from 41- to 100-ka dominant climatic oscillations, occurring within a long-term cooling trend, was associated with an aridity crisis which strongly modified the ecosystems. Starting from the MPT the more favourable climate of central and southern Italy provided propitious environmental conditions for long-term human occupations even during the glacial times. In fact, the human strategy of territory occupation was certainly driven by the availabilities of resources. Prehistoric sites such as Notarchirico (ca. 680–600 ka), La Pineta (ca. 600–620 ka), Guado San Nicola (ca. 380–350 ka) or Ceprano (ca. 345–355 ka) testify to a preferential occupation of the central and southern Apennines valleys during interglacial phases, while later interglacial occupations were oriented towards the coastal plains, as attested by the numerous settlements of the Roma Basin (ca. 300 ka). Faunal remains indicate that human subsistence behaviours benefited from a diversity of exploitable ecosystems, from semi-open to closed environments. In central and southern Italy, several palynological records have already illustrated the regional- and local-scale vegetation dynamic trends. During the Middle Pleistocene climate cycles, mixed mesophytic forests developed during the interglacial periods and withdrew in response to increasing aridity during the glacial episodes. New pollen data from the Boiano Basin (Molise, Italy) attest to the evolution of vegetation and climate between MIS 13 and 9 (ca. 500 to 300 ka). In this basin the persistence of high edaphic humidity, even during the glacial phases, could have favoured the establishment of a refuge area for the arboreal flora and provided subsistence resources for the animal and hominin communities during the Middle Pleistocene. This could have constrained human groups to migrate into such a propitious area. Regarding the local climate evolution during the glacial episodes, the supposed displacement from these sites could be linked to the environmental dynamics solely due to the aridity increase, rather than directly to the global climate changes.

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Role of debris flows in long-term landscape denudation in the central Appalachians of Virginia

Geology ◽

10.1130/0091-7613(2003)031<0339:rodfil>2.0.co;2 ◽

2003 ◽

Vol 31 (4) ◽

pp. 339 ◽

Cited By ~ 56

Author(s):

Louis Scott Eaton ◽

Benjamin A. Morgan ◽

R. Craig Kochel ◽

Alan D. Howard

Keyword(s):

Debris Flows ◽

Central Appalachians

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Is aridity a high-order control on the hydro–geomorphic response of burned landscapes?

International Journal of Wildland Fire ◽

10.1071/wf14079 ◽

2016 ◽

Vol 25 (3) ◽

pp. 262 ◽

Cited By ~ 15

Author(s):

Gary J. Sheridan ◽

Petter Nyman ◽

Christoph Langhans ◽

Jane Cawson ◽

Philip J. Noske ◽

...

Keyword(s):

Debris Flows ◽

Scale Parameter ◽

Landscape Scale ◽

High Order ◽

Net Radiation ◽

Erosion Rates ◽

Geomorphic Response ◽

Eastern Australia ◽

Fire Debris

Fire can result in hydro–geomorphic changes that are spatially variable and difficult to predict. In this research note we compile 294 infiltration measurements and 10 other soil, catchment runoff and erosion datasets from the eastern Victorian uplands in south-eastern Australia and argue that higher aridity (a function of the long-term mean precipitation and net radiation) is associated with lower post-fire infiltration capacities, increasing the chance of surface runoff and strongly increasing the chance of debris flows. Post-fire debris flows were only observed in the more arid locations within the Victorian uplands, and resulted in erosion rates more than two orders of magnitude greater than non-debris flow processes. We therefore argue that aridity is a high-order control on the magnitude of post-wildfire hydro–geomorphic processes. Aridity is a landscape-scale parameter that is mappable at a high resolution and therefore is a useful predictor of the spatial variability of the magnitude of post-fire hydro–geomorphic responses.

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