1,720,998 research outputs found
Analisi dei tassi di erosione a medio termine in un gully permanente della Fossa Bradanica, Basilicata.
No full textThe Use of DEM-Based Approaches to Derive a Priori Information on Flood-Prone Areas
No full textKnowing the location and the extent of areas exposed to floods is the most basic information needed for planning flood management strategies. Unfortunately, a complete identification of these areas is still lacking in many countries. Recent studies have highlighted that a significant amount of information regarding the inundation process is already contained in the structure and morphology of a river basin. Therefore, several geomorphic approaches have been proposed for the delineation of areas exposed to flood inundation using DEMs. Such DEM-based approaches represent a useful tool, characterized by low cost and simple data requirements, for a preliminary identification of the flood-prone areas or to extend flood hazard mapping over large areas. Moreover, geomorphic information may be used as external constraint in remote-sensing algorithms for the identification of inundated areas during or after a flood event
Data Fusion Through Bayesian Methods for Flood Monitoring from Remotely Sensed Data
No full textProducing high-precision flood maps requires integrating and correctly classifying information coming from heterogeneous sources. Methods to perform such integration have to rely on different knowledge bases. A useful tool to perform this task consists in the use of Bayesian methods to assign probabilities to areas being subject to flood phenomena, fusing a priori information and modeling with data coming from radar or optical imagery. In this chapter we review the use of Bayesian networks, an elegant framework to cast probabilistic descriptions of complex systems, applied to flood monitoring from multi-sensor, multi-temporal remotely sensed and ancillary data
Il ruolo del rilievo sull’evoluzione e distribuzione delle forme calanchive in Fossa Bradanica, Basilicata (Italia Meridionale).
No full textImplications of decadal changes in precipitation and land use policy to soil erosion in Basilicata, Italy.
No full textThis paper examines the implications of changes in precipitation and land use to soil erosion from 1955 to 2002 in Basilicata, a hilly
portion of southern Italy. Analysis of daily precipitation records reveals statistically significant trends using both non-parametric and
parametric approaches. The inter-annual variability of precipitation increases in intensity; primarily between October and January. From 1955
to 2000, the length of dry spells greatly increased, while wet days decreased. A land use change map was produced for the three study areas
using aerial photos (1955) and orthophotos (1997 and 2002), integrated with field surveys. Results show that land use is highly dynamic in
Basilicata, especially due to the application of the European Union’s Common Agricultural Policy (CAP) measures. The EU policies resulted
in reclamation of badlands and degraded grasslands for agriculture, principally the cultivation of durum wheat. This farming practice and the
abandonment of some of the remodeled areas have increased the risk of soil erosion and desertification processes, and is manifest in land
degradation by rill networks and gullying
Influenza delle precipitazioni e dei cicli umido-secchi sulla morfogenesi calanchiva in un area semi-arida della Basilicata (Italia meridionale)
No full textThis paper deals with the analysis of the role of the rainfall on the development of badlands in a semi-arid area of eastern Basilicata, locat - ed between the middle valley of the Basento river and the middle-lower valley of the Sinni river. The badlands develop principally on Plio-Pleistocene silty and marly clays, so it is possible to eliminate the lithology as study parameter. Some parameters such as erosivity, mean recurrence of precipitation events of different magnitudes, mean dry and wet spell lenghts, maximum number of dry and wet consecutive days have been calculated relatively to the period 1951-2000. The results show that rain- fall plays an important role on soil erosion. In the whole study area the frequency and the length of dry periods tend to increase whereas the number of the consecutive wet days tends to decrease. In particular, anyway, it results that the pluviometric regime works differently in the Northern and Southern sub-areas. In the former, incised by the Basento river, erosivity and mean frequency of extreme events decidedly de- crease; in the latter, including the Cavone , Agri and Sinni rivers, erosivi-
ty and extreme events with> 30 mm magnitude increase. As a consequence pseudo-karst and mass-movements are widespread in the Southern area, while rilling and gullying control the badland evolution in the Northern area
Global change and long-term gully sediment production dynamics in Basilicata, southern Italy
No full textThe Fossa Bradanica in Basilicata (S Italy) is
affected by almost 15% permanent Pleistocene and Holocene
gullies. In the past decades climate versus land use
management have dramatically increase both the soil loss
rate and the muddy-flooding frequency. In this paper the
impact of global change on soil production rates and erosion/
deposition dynamics at medium-time scale (1949–2000) for
two permanent gullies (Fosso Lavandaio and Fosso San
Teodoro) has been studied. Pluviometric regime, land use
changes and multi-temporal (1949, 1986 and 2000) subtraction
method of digital elevation models have been conducted.
From 1949 to 1986 the sediment production rate was
estimated in 1,988.43 Mg ha-1 year-1 at Fosso Lavandaio
and in 808.5 Mg ha-1 year-1 at Fosso San Teodoro, with
deposition prevailing over erosion processes. From 1986
to 2000 the sediment production rate was estimated in
2,487.92 Mg ha-1 year-1 at Fosso Lavandaio and in
2,883.9 Mg ha-1 year-1 at Fosso San Teodoro, with higher
values of net erosion. The data confirm that the increase in
sedimentation would be due to human activities, in particular
the levelling of gully heads for the production of cereals and
orchards. Differently, the increase of the erosion processes
depends on the recent changes of the pluviometric regime
characterized by the extension of dry horizon and the concentration
of high magnitude precipitation in macro-events
of three to four consecutive days
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Variations on the Author
Get PDF“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
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