48 research outputs found
Recent advances in landslide investigation: Issues and perspectives.
No full textThis is the "Guest editorial" of a Special Issue of the journal Geomorphology which includes 14 papers dealing with landslides selected from two conferences of the International Association of Geomorphologists (IAG): the Regional Conference held in Brasov, Romania, in September 2008 and the Seventh International Conference celebrated in Melbourne, Australia, in July 2009. The Regional Conference, under the theme "Landslides, floods and global environmental change in mountain regions", was organized in a classic landslide area, the Carpathian Mountains.The articles covers a wide geographical and thematic canvas, with a special flavour from Eastern Europe derived from the IAG Regional Conference held in Romania. The study areas include all the major continents with the exception of North America. Eight papers from Europe (Andorra, Czech Republic, Estonia, Poland, Romania, Spain, Switzerland) deal with a wide diversity of topics; magnitude and frequency relationships in the Pyrenees, paleoenvironmental record of landslide activity in the Carpathians, slope instability in glacialacustrine clays in the Estonian coastal plain, landslide characterization in the Bohemian Massif, susceptibility mapping in Romania, mapping and assessment of debris-flow sediment sources in the Swiss Alps, and shallow slides and trenching applied to large landslides in a reservoir in the Pyrenees. Two papers deal with a catastrophic rock slide-avalanche in Japan. There is a paper on the interaction between large dam-forming landslides and fluvial activity in the deepest valley in the world located in Nepal. An article from Venezuela documents very large landslides associated with the Boconó Fault in the Andes. A paper reviews blanket peat landslides in subantartic islands. Finally, one paper discusses the relative role played by climate change and human activity on landslide activity, with numerous examples from New Zealand.The Guest Editorial, beside outlining the main content of each papers, highlights the recent advances in landslide investigation
Unità di vegetazione naturale potenziale e incidenza degli incendi nell’isola di Ponza (Italia centrale).
No full textMorphodinamic mapping of landslide affected slopes: the case of the Groapa Vantului (Romania)
No full textMorphodinamic mapping of landslide affected slopes: the case of the Groapa Vantului (Romania
Economic losses for rural land value due to landslides
No full textA high dynamic environment is typically interested by changes affecting the natural
processes and their related consequences. Landslides do not only alter the landscape,
but substantially affect human activities. When it comes to natural hazards, landslides
have been acknowledged as one of the main causes of human casualties or damage
to assets. Furthermore, economic losses to rural lands are also significant, despite often
being underrated, especially in rural areas. In not densely populated territories, the main
productive activities are in fact often based on the agricultural and pastoral resources.
We intend to propose a methodology that helps to investigate the potential loss of value
(expressed in e) of lands usually exploited for economical profit in rural areas. We test the
method on two case studies, belonging to different European Countries with very different
economical assets and geological, geomorphological, and environmental conditions.
The first study area is located in the Southern Italian Apennines, in the Molise region,
while the second area is located in Buzau County, a region belonging to the Romanian
Curvature Carpathians and Subcarpathians. Our analysis is focused not only on the
actual situation, represented by the past and present landslides, but also on potential
future scenarios for 2050. The scenarios foresee future similar socio-economical and
technological activities, with no major changes expected. The loss estimation is based
on the presence of landslides affecting the rural lands, but it also considers both a present
and future landslide susceptibility scenario. This procedure allowed the estimation of
the economic losses in the two case-study areas, highlighting how the same natural
processes might result in different economical consequences. Following our approach,
the results highlight that for the Italian case study there is a loss of 10.4% for 2007
and 9.9% for 2050 of the total land value as concerns landslides susceptibility. In the
Romanian case study, on the other hand, the loss corresponds to 29.6 and 29.8% for
2010 and 2050, respectively. In addition, the proposed procedure could be considered a
valuable methodological approach to assess landslide-induced economic losses, and be
effectively used during spatial planning activities, aimed at supporting decision makers
for a more sustainable land management
Step-pool sequences of steep mountain streams. A review of their characteristics and origin
No full textSteep mountain streams are the most numerous and ubiquitous river type in the world and represent an essential component of mountain environment and landscape. Coarse grained, steep channels typically show reaches with a staircase bed morphology, known as step-pool sequences, that may alternate with simpler streambed morphology reaches such as runs or plane beds. Though in the last decade the attention of scientists about step-pools has increased remarkably, their morphological characteristics and the processes originating them are still matter of debate. In order to contribute to the understanding of step-pools and their geomorphic significance, a large database has been set up using field and laboratory data reported on both published scientific journals and unpublished studies. The review of the existing data has been paired by some field experiment on large particle entrainment and step-pool dynamics in a mountain stream of the Northern Apennines. The literature data review has shown that very few concepts about step-pool morphology and flow hydraulics can be considered as well established. For instance, many authors report about the inverse relation between step wavelength and streambed gradient, but plot diagrams of field and laboratory data show no evidence of such a relationship. This observation implies that the hypotheses based on such an assumption need at least to be revised. The lack of correlation between step wavelength and slope seems also to be affected by the non homogeneous methods to measure the basic step-pool geometry parameters as the long tail of high values of the step wavelength to channel width ratio indicate compared to a significant clustering of data around the value of one. Many authors assume that step-pool sequences are originated only by long return interval (30-50 years) floods, in mountain streams characterised by sediment supply limited conditions. Field experiment in the northern Apennines have shown that large particles making up the steps can be entrained and steps can be completely removed or new ones formed by flood flows close to or just a bit higher than bankfull stage (2-5 years). Moreover, field observations suggest that the condition of limited sediment supply is not a prerequisite for the formation of step-pool since they were found on the bottom of ephemeral gullies or in small channels incised in very steep (35° - 40°) scree deposits of arid and semi-arid environments. All these findings have fundamental implications on the development of a general theory to explain the origin of step-pool sequences. Substantially, three main hypotheses are reported in the literature: antidunes, maximisation of flow resistance and large keystones control. These theories are analysed in the light of the field experiments carried out in our study mountain streams and compared with a further elaboration of the literature data sets. Improving our understanding of the morphology and dynamics of step-pools will result in a sounder management of steep mountain streams and in eco-compatible interventions for channel restoration in extreme floods or anthropogenic impact aftermaths
La mobilité tectonique et les processus géomorphologiques actuels des subcarpates de la Roumanie
No full textLos Subcárpatos de Rumania, formados por molasas neógenas plegadas asociadadas localmente al flysch paleógeno, están afectados por movimientos tectónicos positivos, con intensidades variables, que influyen de manera evidente en los procesos geomorfológicos actuales, ligados a un clima templado-continental.
El modelado de vertientes se realiza esencialmente por movimientos en masa (deslizamientos, coladas de barro) a los que se unen intensos procesos de arroyamiento.
Los acontecimientos extremos (precipitaciones torrenciales, potentes temblores de tierra) desempeñan el papel principal en el desencadenamiento lento y recrudecimiento de los movimientos en masa. A partir de las investigaciones realizadas, se aprecia que los Subcárpatos se encuentran entre las regiones de Europa más intensamente afectadas por los procesos geomorfológicos actuales
La mobilité tectonique et les processus géomorphologiques actuels des subcarpates de la Roumanie
No full textLos Subcárpatos de Rumania, formados por molasas neógenas plegadas asociadadas localmente al flysch paleógeno, están afectados por movimientos tectónicos positivos, con intensidades variables, que influyen de manera evidente en los procesos geomorfológicos actuales, ligados a un clima templado-continental. El modelado de vertientes se realiza esencialmente por movimientos en masa (deslizamientos, coladas de barro) a los que se unen intensos procesos de arroyamiento. Los acontecimientos extremos (precipitaciones torrenciales, potentes temblores de tierra) desempeñan el papel principal en el desencadenamiento lento y recrudecimiento de los movimientos en masa. A partir de las investigaciones realizadas, se aprecia que los Subcárpatos se encuentran entre las regiones de Europa más intensamente afectadas por los procesos geomorfológicos actuales
Screening for K-Casein (CSN3) Gene Variation in Carpathian Goat Breed by Isoelectric focusing (IEF) and DNA Sequencing
No full textIn goats, k-casein (CSN3) locus is highly polymorphic with up to 16 allele currently characterized. They produce 13 protein variants (CSN3) that were classified in two groups (AIEF and BIEF), according to their isoelectric point. Isoelectric focusing (IEF) of milk samples allows the detection of these two CSN3 groups, but for correct identification of CSN3 alleles DNA based genotyping methods are needed. Therefore the objective of this study was to identify the types of alleles occurring at the CSN3 locus in Carpathian goat breed by using a combined IEF and DNA sequencing approach. IEF analysis of milk samples collected from two Carpathian goat populations reared in Romania revealed two distinct CSN3 patterns. Amplification and sequencing of CSN3 cDNA obtained from these goats revealed four polymorphic sites located in the exon 4 that are responsible for amino acids substitutions, as compared with the reference sequence of A allele. By comparative analysis of IEF and cDNA sequencing data obtained from the two populations, we shown that AIEF alleles are represented by B allele, while BIEF alleles are represented by D allele. However, the variation of CSN3 locus in Carpathian goat breed could be more complex, therefore further studies are needed to characterize it
Opérades dans les 2-catégories et modèles de lois d'échange de structures
No full textLe but de cette thèse est de fournir une construction explicite d'une résolution cofibrante des opérades de Balteanu-Fiedorowicz-Schwänzl-Vogt M_n, qui régissent les catégories monoidales itérées.Dans une première partie de la thèse, nous examinons en détail la définition des structures monoïdales dans les 2-catégories, ainsi que la définition des opérades dans les 2-catégories monoïdales, en prenant la 2-catégorie des catégories comme exemple principal. Ensuite, nous démontrons que la catégorie des opérades dans la catégorie des petites catégories hérite d'une structure de modèle par transfert de la structure de modèle folk sur la catégorie des petites catégories. Nous introduisons une notion de présentation polygraphique des opérades dans la catégorie des petites catégories afin de définir des opérades en terme de générateurs et relations à la fois dans la direction opératique et dans la direction catégorique au niveau des morphismes. Nous réexaminons la définition des opérades M_n en termes de présentations polygraphiques, et nous donnons une présentation de l'opérade M_1^infinity qui fournit une résolution cofibrante de l'opérade M_1 dans la structure de modèle folk. Enfin, nous étudions une généralisation du produit tensoriel de Boardman-Vogt dans le contexte des opérades dans la catégorie des catégories. Nous utilisons cette construction pour fournir une résolution cofibrante M_n^infinity de l'opérade M_n à partir de la résolution M_1^infinity de M_1, et ainsi répondre à la question initiale de la thèse.The goal of this thesis is to give an effective construction of a cofibrant resolution of the Balteanu-Fiedorowicz-Schwänzl-Vogt operads M_n, which govern iterated monoidal categories.In a first part of the thesis, we study thoroughly the definition of monoidal structures in 2-categories, and the definition of operads in monoidal 2-categories, with the 2-category of categories as a main motivating example. Then we prove that the category of operads in the category of small categories inherits a model structure by transfer of the folk model structure on the category of small categories. We introduce a notion of polygraphic presentation of operads in the category of small categories in order to define operads with generators and relations in both the operadic direction and the categorical direction at the morphism level. We revisit the definition of the operads M_n in terms of polygraphic presentations, and we gives a presentation of an operad M_1^infinity that provides a cofibrant resolution of the operad M_1 in the folk modelstructure. Eventually, we study a generalization of the Boardman-Vogt tensor product in the context of operads in the category of small categories. We use this construction to provide a cofibrant resolution M_n^infinity of the operad M_n from the resolution M_1^infinity of M_1, and hence, to address the initial question of the thesis
Opérades dans les 2-catégories et modèles de lois d'échange de structures
No full textThe goal of this thesis is to give an effective construction of a cofibrant resolution of the Balteanu-Fiedorowicz-Schwänzl-Vogt operads M_n, which govern iterated monoidal categories.In a first part of the thesis, we study thoroughly the definition of monoidal structures in 2-categories, and the definition of operads in monoidal 2-categories, with the 2-category of categories as a main motivating example. Then we prove that the category of operads in the category of small categories inherits a model structure by transfer of the folk model structure on the category of small categories. We introduce a notion of polygraphic presentation of operads in the category of small categories in order to define operads with generators and relations in both the operadic direction and the categorical direction at the morphism level. We revisit the definition of the operads M_n in terms of polygraphic presentations, and we gives a presentation of an operad M_1^infinity that provides a cofibrant resolution of the operad M_1 in the folk modelstructure. Eventually, we study a generalization of the Boardman-Vogt tensor product in the context of operads in the category of small categories. We use this construction to provide a cofibrant resolution M_n^infinity of the operad M_n from the resolution M_1^infinity of M_1, and hence, to address the initial question of the thesis.Le but de cette thèse est de fournir une construction explicite d'une résolution cofibrante des opérades de Balteanu-Fiedorowicz-Schwänzl-Vogt M_n, qui régissent les catégories monoidales itérées.Dans une première partie de la thèse, nous examinons en détail la définition des structures monoïdales dans les 2-catégories, ainsi que la définition des opérades dans les 2-catégories monoïdales, en prenant la 2-catégorie des catégories comme exemple principal. Ensuite, nous démontrons que la catégorie des opérades dans la catégorie des petites catégories hérite d'une structure de modèle par transfert de la structure de modèle folk sur la catégorie des petites catégories. Nous introduisons une notion de présentation polygraphique des opérades dans la catégorie des petites catégories afin de définir des opérades en terme de générateurs et relations à la fois dans la direction opératique et dans la direction catégorique au niveau des morphismes. Nous réexaminons la définition des opérades M_n en termes de présentations polygraphiques, et nous donnons une présentation de l'opérade M_1^infinity qui fournit une résolution cofibrante de l'opérade M_1 dans la structure de modèle folk. Enfin, nous étudions une généralisation du produit tensoriel de Boardman-Vogt dans le contexte des opérades dans la catégorie des catégories. Nous utilisons cette construction pour fournir une résolution cofibrante M_n^infinity de l'opérade M_n à partir de la résolution M_1^infinity de M_1, et ainsi répondre à la question initiale de la thèse
