1,721,080 research outputs found
Rappresentazione in carta delle caratteristiche dei sentieri ai fini della mitigazione del rischio geomorfologico.
No full textL’ambiente naturale di alcuni particolari ambiti geografici è in rapida evoluzione non solo per quanto
riguarda le sue variabili, legate alle tendenze climatiche in atto, ma anche in relazione all’aumentata
frequentazione turistica. La maggiore diffusione dei mezzi di risalita in montagna e di
navigazione lungo le coste, rende possibile l’accesso anche a siti altrimenti difficilmente raggiungibili
: ciò porta ad un contatto rapido e diretto con ambienti talvolta mutevoli in tempi brevi. La crescente
richiesta di una maggiore conoscenza dell’ambiente naturale, che si esplica per lo più attraverso
la frequentazione della rete sentieristica, implica la necessità di abbinare alle proposte di percorsi
ed itinerari, note illustrative e carte tematiche di immediata lettura, che evidenzino sia i siti di
interesse naturalistico - culturale sia le possibili situazioni di rischio e di difficoltà di percorrenza
degli itinerari stessi. Esistono infatti alcuni elementi morfologici del territorio che di per sé non
costituiscono una pericolosità in senso stretto ma che, a seconda delle capacità del fruitore, possono
essere fonte indiretta di danno, in quanto rendono difficile l’attraversamento di alcuni punti
specifici o la percorrenza di particolari tratti di sentiero. Contemporaneamente la stagionalità in
alcune regioni climatiche e la variabilità meteorologica possono incrementare sia la pericolosità sia
la vulnerabilità e di conseguenza il rischio per il frequentatore. Obiettivo del presente lavoro è quello
di proporre una simbologia adeguata da inserire sulle carte dei sentieri, e più specificatamente
su quelle geoturistiche, per una rapida e facile identificazione di specifiche situazioni riscontrabili
lungo itinerari: questi simboli, che dovranno riferirsi solo alla percorribilità dell’itinerario e non alla
valorizzazione naturalistica dello stesso, andranno rappresentati su base topografica separata, al
fine di non appesantire la lettura dell’elaborato cartografico principale e dovranno fornire solo
informazioni oggettive che saranno poi interpretate dal fruitore dell’itinerario. La simbologia e le
note terranno conto sia delle caratteristiche costanti dei sentieri che degli elementi variabili, in funzione
anche delle condizioni climatiche o stagionali, a seconda dei diversi ambienti interessati
Genoa ‘the Superba’ old city - Unesco World site - geomorphological heritage
No full textThe coastal city of Genoa is an increasingly popular tourist destination due to its landscape and cultural aspects. Between 1099 and 1815, Genoa was a maritime republic with naval power and it is today the largest harbour in Italy and the second in the Mediterranean. There are, however, some less known aspects of Genoa cultural heritage connected to urban geomorphology and geo-diversity; in addition to the existing landscape and artistic values, these could constitute another element of interest for tourists and residents. Due to historical and recent urban sprawl, the former morphology of Genoa (the ‘Superba’) which contributed to the city military and economic success, is today largely invisible. The stratification of urban sprawl phases characterises many ancient cities in the Mediterranean: despite centuries of human intervention, however, the original features of the territory can still be recognized in present-day landscapes. This study shows the results of long-standing geomorphological surveys carried out in Genoa which allowed a detailed reconstruction of the geomorphological setting of the historical centre, a Unesco World Heritage site since 2006 In addition, this investigation allowed us to identify some sites of geological-environmental and geomorphological interest which are worth of being conserved and promoted for tourism. In particular, we identified three thematic urban trails on the hydro-geomorphological evolution of Genoa historical centre and the environmental-geological settings which conditioned the development of the city: the ‘vertical Genoa trail’, on the funicular Zecca-Righi and along the old ‘creuze’, in order to underline the slopes’ verticality; the ‘Waterways trail’, along the final stretch of the old aqueduct and many historical fountains; the ‘Genoa zero trail’, which develops from east to west across the old centre, looking for traces of the city’s old morphology under the current urban cover. These three trails show how history, urbanisation and geomorphological features of the area are strictly connected. Their promotion for tourism purposes aims to facilitate the understanding and divulgation of what we know about Genoa’s geomorphology, alongside with other important features of interests such as the coastal landscape and the cultural and historical heritage
Morphometric Analysis of Trail Network and Tourist Vulnerability in a Highly Frequented Protected Area
Full text linkIncreasing interest in the natural environment and greater hiking activity have resulted in higher anthropogenic pressure in areas characterized by a geographic/physical setting that could present hazardous conditions. The development of these activities is influenced by the peculiar geomorphological and climatic conditions of the area. Visitors and hikers do not always have adequate cultural background and full awareness of natural dynamics, including the possibility of incurring hazardous conditions. For its cultural and landscape value and extraordinary trail network, the Portofino Promontory is frequented by more than a hundred thousand of hikers a year. However, due to the geomorphological characteristics of the area, the morphological features of the trail network (i.e., exposed paths, steep ups and downs, rocky sections with cables, etc.) and the peculiar meteo-climatic conditions, the number of accidents involving hikers has increased in the most recent years. This research uses a detailed LiDAR survey, a morphometric analysis, and a significant dataset of information on the frequentation of the hiking trail network and on the number of rescue operations carried out by the National Mountain Rescue and Speleological Service (CNSAS). These data have been related to the physical-geographical characteristics of the area. The results can be a useful tool for land management by the Park Authority
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Effects of urbanization on river morphology in a Mediterranean coastal city (Genova, Italy)
No full textFrom the geomorphological point of view, urbanization changes fluvial systems more drastically than any other single human activity. Its impact on rivers is of interest as it results in serious issues concerning geomorphic instability, ecosystem service reduction, and geo-hydrological risk increase. The present study provides a quantitative and qualitative assessment of landscape changes driven by urbanization, which occurred from the mid-19th century to the present day along the lower reaches of the Bisagno and Polcevera rivers and their tributaries in the Mediterranean coastal city of Genova (NW Italy). The bankfull channel morphological adjustments, the minor hydrographic network disappearance, the land use and land cover changes, and the current physical accessibility of river margins were investigated. This work is based on collection and review of historical data, photograph interpretation, GIS analysis, and field surveys.
Urbanization essentially occurred between the mid-19th century and the late 1930s. The bankfull channel of the Bisagno and Polcevera rivers experienced large narrowing associated with widespread establishment of channelization structures. The minor hydrographic network essentially disappeared underground. After the 1930s, further minor anthropogenic interventions were implemented to accommodate urban expansion and consolidate channelization works; however, the overall geomorphological setting remained unchanged. The geomorphological evolution of the Bisagno and Polcevera rivers followed three different phases associated with the urban expansion process. Nowadays, the study area is completely urbanized, the fluvial stems flowing through the valley floor are totally disconnected from their adjacent areas, the main
rivers show a relevant geomorphological stability induced by anthropogenic pressures, and the accessibility of river margins for people is rather limited. The outcomes from this study represent an essential knowledge base for technicians and policymakers to plan urban development and inform effective and sustainable management measures. Moreover, they provide insights into the medium- and short-term morphological evolution of urban rivers
MAN-MADE LANDFORMS SURVEY AND MAPPING IN AN URBAN HISTORICAL CENTER ON COASTAL MEDITERRANEAN ENVIRONMENT
No full textThis paper documents the evolution of the urban geomorphological setting of the historical heart of the city of Genoa (Liguria, Italy). Since the Middle Ages, the city and its harbour have progressively grown, reaching their greatest extent in the 1950s. Today it has an area of 8.5 km2 and it includes seven small catchments with surfaces ranging from 0.5 to 2.4 km2. Their urbanized surface ranges from just less than 30% up to more than 80%. Human interventions have almost completely reshaped and modified the original morphology. The identification of artificial landforms built over the former natural landforms was carried out through multi-temporal cartographical and photographical comparison, and the analysis of geo-thematic cartography and documentation by the Basin Master Plan (Piano di Bacino) and Genoa City Hall Plan. In addition stratigraphy data from the regional database were analysed and several geomorphological surveys were carried out in the area. Artificial landforms were mapped by applying an experimental geomorphological classification currently being developed by the Working Groups of the Italian Association of Physical Geography and Geomorphology (AIGEO). The main geomorphic modifications are: slope fillings retained by walls (mainly due to roads and buildings); excavation areas (often connected to historical quarries); sea embankments (for harbour growth) and artificial modifications of the drainage network (culverts, stream diversions and canals). All of these reduced the flow sections. These morphological changes have significantly increased the geo-hydrological risk in Genoa, which is currently one of the most emblematic Italian case studies for recurrent flood events, especially in the light of the modified rainfall regime due to recent climate change
Short-term GIS analysis for the assessment of the recent active-channel planform adjustments in a widening, highly altered river: The Scrivia river, Italy
No full textFrom the 1990s onwards several Italian rivers have experienced a recent phase characterized by active-channel widening and, generally, by bed-level stability or slight aggradation. However, its triggering factors and its diffusion, along with the relationship between active-channel planform dynamics and vertical adjustments, are still quite debated and only few studies are available. This research deals with the active-channel planform changes occurred along the Scrivia River floodplain reach (NW Italy) over the period 1999-2019 and it aims at investigating in detail the ongoing geomorphological processes under the river management perspective. The study is based on a quantitative multitemporal analysis of aerial photographs and satellite images performed in a GIS environment and supported by field surveys. The outcomes revealed a generalized trend of gentle active-channel widening together with widespread bank instability and several (26% of total banks) intense and localized bank retreats involving both the modern floodplain and the recent terrace. In the investigated 20-year period, the active-channel area has increased by 22.7% (from 613.6 to 753.0 ha), its mean width by 25% (from 151.5 to 189.3 m), whereas no relevant length variations have been noticed. These morphological dynamics have been more or less pronounced both at reach scale and over time. The extreme floods occurred in the investigated period can be considered the most important triggering factor of the active-channel planform changes, most probably together with an increase of the reach-scale unit stream power due to changes in the channel geometry occurred over the 20th century
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
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