1,720,976 research outputs found
A Methodological Tool to Assess Erosion Susceptibility of High Coastal Sectors: Case Studies from Campania Region (Southern Italy)
No full textHigh coastal sectors constitute the most widespread coastal environment and, under the present accelerated sea-level rise scenario, are suffering huge impacts in terms of erosion. The aim of this paper is the proposal of a new methodological approach for the assessment of their susceptibility to erosive processes. The method is based on the combination of two matrices, i.e., a matrix considering the main physical elements (essentially morphological and geotechnical characteristics) that determine the proneness to erosion of a specific high coastal sector, and a forcing matrix, which describes the forcing agents affecting the considered sector. Firstly, several variables were selected to construct each one of the two matrices according to existing studies and, in a second step, they were interpolated to obtain the susceptibility matrix (CSIx). The approach was applied to Procida Island and Cilento promontory, both located in southern Italy. Results obtained were validated by comparing them with cliff retreat data obtained by means of aerial photographs and satellite images. The analysis shows that the greater part of the analyzed high coastal sectors belongs to the high-susceptibility class due to the combination of adverse morphological, geotechnical and forcing characteristics. Such sectors can be considered "hotspots" that require an increase in monitoring programs and, at places, urgent protective actions
Palaeo-landscape reconstruction and assessment of long-term erosion rates through DEM analysis: preliminary results from the Molise Apennine (Central-Southern Italy)
No full textRelative Sea-Level Changes and Their Impact on Coastal Zones: Past and Future Scenarios from Cases Studies around the World
No full textIn recent decades, the study of sea-level changes as recorded along entire coastlines around the world has been a primary scientific focus in climate change studies; it allows the exploration of past landscape evolution, geomorphological processes, human impact, and system response to develop future perspectives [...
Spettroscopia VIS-NIR per la cartografia digitale dei suoli a scala aziendale. Il caso di studio dell'azienda GiòSole
No full textI suoli sono raramente omogenei, soprattutto a diverse scale spaziali (Odlare et al., 2005). Variazioni delle proprietà dei suoli, particolarmente evidenti su scala regionale e comprensoriale, possono verificarsi, in modo rilevante, anche all’interno di singoli appezzamenti, a causa di mutamenti nella topografia e nella successione degli strati dei materiali pedogenetici o per effetto di passate gestioni antropiche (Brady e Weill, 2002). Nonostante ciò, i suoli sono tradizionalmente trattati come omogenei, con possibili effetti negativi sul rendimento delle colture, sui costi di gestione e sull’ambiente. Tali effetti possono essere, tuttavia, contenuti, se non del tutto evitati, adeguando la gestione agronomica alle condizioni specifiche del sito, valutate attraverso la corretta conoscenza della variabilità intraziendale dei suoli. E’ questa la finalità dell’insieme di Agrotecniche meglio conosciuta come “Agricoltura di precisione”.
Un modo per investigare la variabilità intraziendale dei suoli potrebbe essere la produzione di carte dettagliate, basate su un grande numero di analisi chimiche e fisiche tradizionali. Queste analisi sono, tuttavia, lunghe e costose. Di qui la necessità di investigare/collaudare tecniche alternative di caratterizzazione dei suoli. Negli ultimi anni è stata rivolta particolare attenzione alla spettroscopia della riflettanza nel dominio visibile-infrarosso vicino (spettroscopia vis-NIR) (Conforti et al., 2013, Leone et al., 2012, 2013), una tecnica rapida, economica, non invasiva e non distruttiva, che richiede solo una minima preparazione dei campioni e che non necessita dell’uso di prodotti chimici pericolosi (Viscarra Rossel et al., 2006).
La spettroscopia vis-NIR è basata sulla misura di riflettanza (Milton, 1987) – definita dal rapporto tra la radiazione riflessa dalla superficie del suolo (o altro materiale) e quella incidente su di essa, alle diverse lunghezze d’onda, tra 350 e 2500 nm (Drury, 1993) – e sulla valutazione delle sue relazioni con le proprietà dei suoli. Nella predetta regione spettrale, ciascun costituente del suolo presenta, infatti, specifiche proprietà di assorbimento, dovute a transizioni energetiche, di tipo elettronico (nel visibile) o vibrazionale (nell’infrarosso vicino) (Leone et al., 2000). Pertanto, suoli con differenti proprietà chimiche, fisiche e mineralogiche mostrano differenti caratteristiche spettrali, che possono essere convenientemente analizzate per acquisire informazioni qualitative/quantitative sulle predette proprietà (Leone et al., 2012, 2013), o per analizzare e cartografare la distribuzione spaziale della copertura pedologica (digital soil mapping) (Odler et al., 2005, Viscarra Rossel e Behrens, 2010).
Il CNR-ISAFoM è da diversi anni impegnato in studi riguardanti l’applicazione della spettroscopia vis-NIR alla predizione delle proprietà dei suoli di differenti sistemi agricoli e forestali del Mediterraneo (Leone et al., 2012, 2013). Più recentemente, lo stesso Istituto ha avviato una serie di attività di ricerca finalizzate alla valutazione delle potenzialità della spettroscopia vis-NIR nella cartografia digitale dei suoli (Buttafuoco et al., 2010; Conforti et al., 2013). Nell’ambito di tali attività si inquadra anche il presente lavoro, realizzato con il contributo del progetto DERFAM – PSR 124 Regione Campania, il cui obiettivo specifico è la realizzazione di una carta digitale dei suoli a grande scala, basata sull’uso della spettroscopia vis-NIR e di metodi di analisi statistica multivariata e geostatistici
River channel adjustment in Southern Italy over the past 150 years and implications for channel recovery
No full textMulti-temporal GIS analysis of topographic maps and aerial photographs along with topographic and geomorphological
surveys are used to assess evolutionary trends and key control factors of channel adjustments for
five major rivers in southern Italy (the Trigno, Biferno, Volturno, Sinni and Crati rivers) to support assessment
of channel recovery and river restoration.
Three distinct phases of channel adjustment are identified over the past 150 years primarily driven by human disturbances.
Firstly, slight channel widening dominated from the last decades of the nineteenth century to the
1950s. Secondly, from the 1950s to the end of the 1990s, altered sediment fluxes induced by in-channel mining
and channel works brought aboutmoderate to very intense incision (up to 6–7m) accompanied by strong channel
narrowing (up to 96%) and changes in channel configuration from multi-threaded to single-threaded patterns.
Thirdly, the period from around 2000 to 2015 has been characterized by channel stabilization and local
widening. Evolutionary trajectories of the rivers studied are quite similar to those reconstructed for other Italian
rivers, particularly regarding the second phase of channel adjustments and ongoing transitions towards channel
recovery in somereaches. Analyses of river dynamics, recovery potential and connectivity with sediment sources
of the study reaches, framed in their catchment context, can be used as part of awider interdisciplinary approach
that views effective river restoration alongside sustainable and risk-reduced river management
Ongoing channel changes in some major rivers in southern Italy
No full textSome major rivers in southern Italy (Trigno, Biferno, Fortore and Volturno), as most of Italy's rivers, have suffered significant channel changes during the last 60 years. Channel adjustments mainly consisted in channel narrowing and bed lowering coupled with pattern changes. Over the last 10-15 years, these rivers have undergone some important modifications in their evolutionary trends. More specifically, the Trigno River and the reaches of the Fortore River located upstream the Occhito dam are interested by moderate channel recovery, while the Volturno and Biferno rivers and the Fortore reaches located downstream the dam are affected by slight channel recovery or no significant changes in morphology. Key driving factors of these recent evolutionary trends seem to be the occurrence of major flood events and the degree of channel mobility that is conditioned by channel works and riparian woody vegetation
Recent channel adjustments and riparian vegetation: some examples from Molise (Italy)
No full textAn integrated geomorphological and ecological approach was adopted
to investigate the relation between recent channel adjustments and riparian
vegetation evolution by performing a large-scale multi-temporal
analysis of channel and land cover features and a study of the present-day
floristic setting along the three major river systems present in Molise
(Southern Italy), the Volturno, Biferno and Trigno. Our results highlight
the major channel adjustments that occurred between 1954 and 2009
consisting in progressive morphological changes, extreme channel narrowing
(between 84% and 97%) and moderate to very intense channel
incision (between 2 and 10.5 m). These channel adjustments led to the
progressive stabilization of most of the formerly active channel systems
and were accompanied by substantial changes in the riparian vegetation
which now appears largely, but not completely, in equilibrium with the
present river dynamics. Major differences may be noted between the
studied river reaches in relation to their state of naturalness, floristic richness
and differentiation in vegetation types, which appear particularly
controlled by the amount of channel incision and human disturbance.
Our findings underline the importance of fluvial dynamics and trends in
controlling the development and structure of riparian vegetation and the
connected ecological status of river system
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