The Subsurface Geology and Landscape Evolution of the Volturno Coastal Plain, Italy: Interplay between Tectonics and Sea-Level Changes during the Quaternary

The Volturno alluvial-coastal plain is a relevant feature of the Tyrrhenian side of southern Italy. Its plan-view squared shape is due to Pliocene-Quaternary block-faulting of the western flank of the south-Apennines chain. On the basis of the stratigraphic analysis of almost 700 borehole logs and new geomorphological survey, an accurate paleoenvironmental reconstruction before and after the Campania Ignimbrite (CI; about 40 ky B.P.) eruption is here presented. Tectonics and eustatic forcing have been both taken into account to completely picture the evolution of the coastal plain during Late Quaternary times. The upper Pleistocene-Holocene infill of the Volturno plain has been here re-organized in a new stratigraphic framework, which includes seven depositional units. Structural analysis showed that two sets of faults displaced the CI, so accounting for recent tectonic activity. Yet Late Quaternary tectonics is rather mild, as evidenced by the decametric vertical separations operated by those faults. The average slip rate, which would represent the tectonic subsidence rate of the plain, is about 0.5 mm/yr. A grid of cross sections shows the stratigraphic architecture which resulted from interactions among eustatic changes, tectonics and sedimentary input variations. On the basis of boreholes analysis, the trend of the CI roof was reconstructed. An asymmetrical shape of its ancient morphology—with a steeper slope toward the north-west border—and the lack of coincidence between the present course of the Volturno River and the main buried bedrock incision, are significant achievements of this study. Finally, the morpho-evolutionary path of the Volturno plain has been discussed

Evoluzione recente e rischio di erosione della Costa Molisana (Italia Meridionale)

As documented by various recent studies (AUCELLI et alii, 2004; FAILLACE, 2004; IANNANTUONO et alii, 2005; GRUPPO NAZIONALE PER LA RICERCA DELL’AMBIENTE COSTIERO, 2006a; AUCELLI et alii, 2007; IANNANTUONO, 2007), the evolution of the 36 km long Molise coast during the last fifty years is characterised by a prevailing tendency to shoreline retreat. The aim of the present paper is to provide a precise description of the Molise coast with reference to its coastal morphology along with a detailed frame of the evolution of its shoreline and first indications on the potential erosion risk. The Molise coast that includes ca. 13 km of high coast behaves altogether as a low coast system, because the cliffs limiting the high coast to the sea are located, except for the promontory of Termoli, at variable distance from the shoreline. Beaches are present nearly all along the coast and anthropic structures frequently are located along their inner edges. To analyse shoreline variations in detail, the Molise coast was subdivided in nine reaches (T1-T9) of different lengths and characters. Quantitative analyses on linear shoreline variations and related surface changes were carried out for the 1954-2003 time interval and relative sub-periods 1954-1992 and 1992-2003. From 1954 to 2003, the general shoreline retreat caused a total loss of ca. 1.090.000 m2 of coastal area (beaches, dunes, deltaic and retro-dune areas). The most sensible reaches to erosion are T1 and T7 that respectively comprise the mouths of the Trigno and Biferno rivers, which experienced in this period a retreat of ca. 250 and 350 metres, respectively. A consistent acceleration of shoreline retreat with time is shown by the comparison between sub-periods 1954-1992 and 1992-2003. Though the second period is much shorter (11 years vs. 38 years), T1 and T7, in particular, totalize nearly 50% of the surface losses that occurred during the precedent period. Due to such an acceleration, during the second period ca. 32% of the total erosion occurred, giving rise to a loss of ca. 348.609 m2. For reaches T1 and T7, the average annual retreat rates changed from respectively 2.37 and 3.24 m/y to 4.24 and 4.74 m/y during the second period, when reach T7 underwent a maximum retreat of about 231 metres which corresponds to an average annual retreat of 21 m/y. The reconstructed acceleration of erosion is in net contrast to the increasing protection of the coast by defense structures as evident above all for reach T7. In order to better understand this apparent inconsistency, and the consequent hypothesis for a possible meteoclimatic influence (already outlined for part of the Molise coast by AUCELLI et alii, 2007), a detailed analysis of the period 1992-2003, subdivided therefore into sub-periods 1992-1997, 1997- 2000, 2000-2003, was carried out. This analysis showed consistent differences between the distinguished sub-periods in relation to average annual shoreline variations and the percentage with which each reach contributed to erosion. The observed differences strongly support the hypothesis that variations of meteomarine conditions have strongly favoured erosion during the second period, and in particular during sub-period 2000-2003, thus outlining the need to adequately consider such climatic influence when developing potential erosion scenaries related to climate change. Starting from the basic morphological and topographical features of the Molise coast, in order to examine the potential erosion risk, the rates of annual average linear shoreline variations for periods 1954- 1992 and 1992-2003 were examined on the basis of the risk scheme developed by GORNITZ et alii (1994). Such an examination allowed to evaluate the degree of erosion risk for each reach and to attribute, in particular, a very high erosion risk to reaches T1 and T7, which, indeed, are the main responsible for the observed shoreline instability. Further analyses carried out on coastal sectors characterised by the occurrence of constructions located up to ca. 200 m from the current shoreline along the inner edges of the beaches, allowed to calculate the potential time span required by marine erosion to possibly affect the constructions. Said calculations point out for the northern sectors of reaches T1 and T7 time spans of 13,5 and 22 years, respectively, and therefore a real, and very high erosion risk

VNIR spectrometry coupled with geostatistics for spatial prediction of soil erosion in sample area of Calabria region (southern Italy)

Soil erosion is one of the most serious types of land degradation and it has severe economic and environmental impacts in the Mediterranean belt, as well as in large areas of the Italian territory. Soil erosion can be evaluated by soil properties such as organic matter, calcium carbonate, texture, aggregation structure, infiltration capacity, etc. The aim of the study was to test laboratory reflectance spectroscopy in the visible near infrared (VNIR) range as a tool to develop an empirical model for predicting specific soil properties (organic matter and calcium carbonate content) as indicators of soil condition and erosion severity. The study was conducted in the Turbolo watershed representative of the pedo-environmental variability of the Calabria region, southern Italy. In this watershed 215 topsoil samples, representative of different soil types and various soil degradation conditions were collected and analysed for soil organic matter (SOM), calcium carbonate and spectroscopic measurements. The partial least squared regression (PLSR) analysis was applied to establish relationships between spectral reflectance and two soil properties. PLSR was performed on 161 of the 215 available samples. The optimum number of factors to retain in the calibration model was determined by cross validation. The models were independently validated and results were satisfactory. The results of this work suggest that laboratory reflectance spectroscopy in the VNIR (350-2500 nm range) coupled with geostatistics analysis can be used as tools for evaluating and mapping spatial pattern of the SOM and calcium carbonate, as well as a method for a quick screening of soil erosion conditions

The tropical storm Noel and its effects on the territory of the Dominican Republic

In the period between the end of October and the beginning of November 2007, the Dominican Republic was hit by the tropical storm Noel, then turned into hurricane in its movement toward the Californian coasts. The passage of Noel was accompanied by huge precipitation especially in the south-western part of the country. In some areas, the rainfall registered in 6 days exceeded 700 mm, i.e., more than two-thirds of the mean annual precipitation. The return periods calculated for this rainfall event vary greatly from region to region: while they locally reach 200 years, such as in San Jose´ de Ocoa (50 km west of Santo Domingo), in other areas, as for instance in the territory of the capital Santo Domingo, return periods do not exceed 20 years. The tropical storm caused huge damage both in terms of human victims and economic losses, related to diffused inundations and landslide phenomena, which may be attributed only partially to the exceptionality of the event. As a matter of fact, in many regions, the inadequate answer of the territory—widely characterized by serious problems of land degradation and an almost complete lack of territorial planning—appears to be the major responsible for the occurred negative effects. The impact assessment, based on the calculation of an Impact Index, confirms this statement

Geomorphological Map of the area between Frosolone and Trivento (Molise, Italy)

A 1:50,000-scale geomorphological map of the area between the settlements of Frosolone and Trivento (Molise Region, Italy) is presented and discussed in this paper. Field surveys and air photo interpretations allowed the characterization of the main morphological landforms of the study area, drawn from the reduction of an original 1:5,000-scale field map. The landforms have been grouped on the basis of the main controlling factors, as follows: i) tectonic and structural landforms; ii) slope landforms; iii) karst landforms; iv) fluvial landforms. This map shows the distribution of the geomorphic processes presently active, as well as the main relic landforms. Consequently, the collected data aim to provide a useful and easy tool for land planning policy; in addition, since the study area represents a typical geomorphic scenario of the southern Apennines, the data produced could be used in developing more widely-applicable landscape evolution models

An integrated stratigraphical approach to the Middle Pleistocene succession of the Sessano basin (Molise, Italy)

An integrated stratigraphical approach was applied to the Sessano sedimentary succession (Molise), investigated through an 80-m core and an 11-m trench section. The lithostratigraphical study allowed reconstruction of the palaeoenvironmental conditions during the existence of a palaeo-marsh. Based on tephrostratigraphical analysis, the significant volcanoclastic inputs recorded along the Sessano succession were correlated to the explosive activity of the nearby Roccamonfina volcano and in particular to the high-K series (HKS) period of activity, lasted from 546 to 364 ka. The 40Ar/39Ar age of 437.9 1.9 ka obtained at the base of the trench section, which stratigraphically overlaps the core succession, confirms the tephrostratigraphical model and indicates that the marsh dried up during the glacial phase of Marine Isotope Stage (MIS) 12. On this basis, the glacial–interglacial cycle recognised in the core through pollen analysis was ascribed to MIS 14 and 13, while the interglacial phase identified at the core base was tentatively ascribed to MIS 15. The duration of the marshy phase was estimated between 130 and 150 ka. The floral composition of the pollen spectra shows a more modern character with respect to coeval pollen records from Campania, confirming that the heterochronous disappearance of the last subtropical elements from Italy had a latitudinal character

Stratigrafia ed assetto geometrico dell’Unità del Sannio nel settore settentrionale dei monti del Matese

New stratigraphic and biostratigraphic data arising from the realization of the Sheet No. 405 "Campobasso" of the new Geological map of Italy (1:50.000 scale - CARG Project) allowed, for the first time in this area, to stratigraphically and cartographically define all the intervals composing the basinal Sannio Unit Auct.. Structural analysis and the chronostratigraphic redefinition of siliciclastic deposits covering the Sannio Unit and the carbonate platform successions of the Matese- Frosolone Units, indicate two main evolutionary stages in the Miocene- Pliocene structuring of this portion of the Southern Apennines. In the first stage, starting before Serravallian times, E-verging contraction affected exclusively the basinal units together with their siliciclastic cover. During the second stage, beginning after early Messinian times, NE-verging compression involved both the basinal Sannio Unit and the Matese-Frosolone Units

Coastal risk assessment of a micro-tidal littoral plain in response to sea level rise

This paper illustrates an index-based coastal risk assessment that was performed on a micro-tidal alluvial plain taking into account the relative sea level rise (RSLR) for the evaluation of coastal vulnerability and exposure. This process took into account both the inundation of inshore land and the beach retreat due to storm surge, calculated on the basis of geomorphological data (bathymetry, sedimentology and beach width) and wave climate. The evaluation process was conceived with reference to a low and high hazard, associated with a wave storm with 1 year and 50 years return period. For the latter case, the response to RSLR was calculated taking into account both isostatic response and ice cap melting due to global warming, while the vertical land movement was assessed taking into account the different its rates in the northern and southern coastal area. The exposure and the damage of the coastal assets were evaluated with a simplified conceptual framework, which uses land cover data and a statistical population dataset. The risk assessment procedure was applied to Sele coastal plain, which involves numerous properties and important infrastructures, and is strongly susceptible to marine inundations. A sensitivity analysis of the vulnerability and the risk relative to different hazards and to RSLR was performed. Moreover, the final risk assessment classification was validated with a conceptual framework based on the observed damage ranking related to the tested coastal area. The obtained results showed that the northern high density urban areas were characterized by the highest risk, followed by some central areas with strong localized erosive focus. On the contrary, the southern zones, with wider beaches and almost intact dunes, were characterized by the lowest risk level. The results of this study were used for the development of a coastal protection project which, in fact, provided a different scheme for the coastline northwards and southwards of the Sele river mouth, according to the different risk ranking established

Studio geomorfopedologico dei fenomeni erosivi nel bacino del T.Turbolo (Calabria settentrionale) con il contributo della spettrometria della riflettanza

Dottorato di Ricerca in Scienze della Terra, XXI Ciclo, a.a.2005-2008Università della Calabri