73 research outputs found
Multitemporal dendrogeomorphological analysis of slope instability in Upper Orcia Valley (Southern Tuscany, Italy)
The Upper Orcia Valley (Southern Tuscany, Italy) is a key site for the
comprehension of denudation processes typically acting in Mediterranean
badlands (calanchi) areas, thanks to the availability of long-lasting
erosion monitoring datasets and the rapidity of erosion processes development.
These features make the area suitable as an open air laboratory
for the study of badlands dynamic and changes in geoheritage due to
erosion (i.e. active geomorphosites).
Decadal multitemporal investigations on the erosion rates and the
geomorphological dynamics of the study area allowed to highlight a decrease
in the average water erosion rates during the last 60 years. More in
detail, a reduction of bare land and, consequently, of erosion processes
effectiveness and a contemporary increasing frequency of mass wasting
events were recorded. These trends can be partly related to the land cover
changes occurred in the study area from the 1950s onwards, which
consist of the significant increase of reforestation practices and important
other forms of human impacts on slopes, mainly land levelling for
agricultural exploitation.
In order to better identify the most significant phases of geomorphological
instability occurred in this area during the last decades, an
integrated approach based on multitemporal geomorphological mapping
and dendrogeomorphology analysis on specimen of Pinus nigra Arn.
was used. In detail, trees colonizing a denudation slope located in the
surrounding of the Radicofani town (Tuscany, Italy) and characterized
by calanchi and shallow mass movements deposits, were analyzed for
the 1985-2012 time period. The analysis of the growth anomaly indexes
and of compression wood allowed to determine a spatio-temporal differentiation
along the slope and respect to an undisturbed reference site.
The negative anomaly index results to be more pronounced in the trees
located on the investigated slope with respect to the ones sampled in
a non-disturbed area. Compression wood characterizes trees on slope
sectors mainly affected by runoff and/or mass movements with a different
persistence. Erosion rates were finally calculated through dendrogeomorphological
analysis on tree roots exposure (0.31-3 cm/y runoff
prevailing; 5.86-27.5 cm/y, mass movements prevailing). Dendrogeomorphological
results are in accordance with those obtained in the investigated
areas with multitemporal photogrammetric and geomorphologic
analyses
Geomorphological classification of urban landscapes. The case study of Rome (Italy)
The results of a long-lasting geomorphological survey carried out in Rome are summarized. A
method aimed at integrating survey data, historical maps, aerial photographs and
archaeological and geomorphological literature produced a geomorphological map of the
present-day historical centre. The geomorphology of Rome is related to the
paleogeographical conditions prior to the founding of the City; they allow us to recognize
the stages of landscape evolution of the ancient Caput Mundi (Capital of the World). The
study area has been affected by continuous man-made changes to the drainage network
and to the topographic surface over the last 3000 years. It has forced the authors to develop
innovative solutions to undertake effective analysis of the urban environment and the
legend of the geomorphological map in this peculiar context. The resulting map is useful for
urban planning and archaeological research
Contribution for an urban geomorphoheritage assessment method. Proposal from three geomorphosites in Rome (Italy)
Urban geomorphology has important implications in spatial planning of human activities, and it also has a
geotouristic potential due to the relationship between cultural and geomorphological heritage. Despite the introduction
of the term Anthropocene to describe the deep influence that human activities have had in recent times on Earth
evolution, urban geomorphological heritage studies are relatively rare and limited and urban geotourism development
is recent. The analysis of the complex urban landscape often need the integration of multidisciplinary data. This study
aims to propose the first urban geomorphoheritage assessment method, which originates after long-lasting previous
geomorphological and geotouristic studies on Rome city centre, it depict rare examples of the geomorphological
mapping of a metropolis and, at the same time, of an inventory of urban geomorphosites. The proposal is applied to
geomorphosites in the Esquilino neighbourhood of Rome, whose analysis confirm the need for an ad hoc method for
assessing urban geomorphosites, as already highlighted in the most recent literature on the topic. The urban geomorphoheritage
assessment method is based on: (i) the urban geomorphological analysis by means of multitemporal and
multidisciplinary data; (ii) the geomorphosite inventory; and (iii) the geomorphoheritage assessment and enhancement.
One challenge is to assess invisible geomorphosites that are widespread in urban context. To this aim, we reworked
the attributes describing the Value of a site for Geotourism in order to build up a specific methodology for the
analysis of the urban geomorphological heritage
Geomorphology of the historic centre of the Urbs (Rome, Italy)
Based on long-lasting multidisciplinary and multitemporal investigations, in 2016 the first geomorphological map of the central area of Rome was presented. It introduced innovative solutions for cartographic restitution of urban landforms. Under this work, the urban geomorphological analysis delved deeper, because the study focused on the smaller area of the Urbs, the ancient city centre that has been modified by human activities over millennia. The main goal of the new study was to verify if the 1:5000 scale survey could allow to improve the legend symbols, in order to better represent landforms from natural and anthropogenic processes in urban environment. Since the map scale was doubled compared with the previous and consequently the map area available was four times bigger, we were able to provide much more details. Moreover, results better highlighted the applicative significance of urban geomorphological maps as complementary tool for the assessment of natural hazards and risks
Transcutaneous Spinal Direct Current Stimulation (tsDCS) Modulates Human Corticospinal System Excitability
This study aimed to assess the effects of thoracic anodal and cathodal transcutaneous spinal direct current stimulation (tsDCS) on upper- and lower-limb corticospinal excitability. Yet, despite studies assessing thoracic tsDCS influences the spinal ascending tract and reflexes, none assessed the effects of this technique over upper- and lower-limb corticomotorneuronal connections. In 14 healthy subjects we recorded motor evoked potentials (MEPs) elicited by transcranial magnetic stimulation (TMS) from abductor hallucis (AH) and hand abductor digiti minimi (ADM) muscles before (baseline, B), and at a different time-points (0 and 30 minutes) after anodal or cathodal tsDCS (2.5 mA, 20 minutes, T9-T11 level). In 8 of the 14 subjects we also tested the soleus H-reflex, the F-waves from AH and ADM before and after tsDCS. Both anodal and cathodal tsDCS left the upper-limb MEPs and F-wave unchanged. Conversely, while leaving lower-limb H-reflex unchanged, they oppositely affected lower-limb MEPs: whereas anodal tsDCS increased resting motor threshold (mean\ub1SEM 107.33 \ub1 3.3%, increase immediately after tsDCS, and 108.37 \ub1 3.2% increase 30 min after tsDCS compared to baseline), and had no effects on MEP area and latency, cathodal tsDCS increased MEP area (139.71 \ub1 12.9% increase immediately after tsDCS and 132.74 \ub122.0% increase 30 min after tsDCS compared to baseline) without affecting resting motor threshold and MEP latency. Our results show that tsDCS induces polarity specific changes in corticospinal excitability that last for more than 30 min after tsDCS offset and selectively affect responses in lower-limb muscles innervated by lumbar and sacral motorneurons
Landslide susceptibility assessment in the Upper Orcia Valley (Southern Tuscany, Italy) through conditional analysis: a contribution to the unbiased selection of causal factors
Abstract. In this work the conditional multivariate analysis was applied to evaluate landslide susceptibility in the Upper Orcia River Basin (Tuscany, Italy), where widespread denudation processes and agricultural practices have a mutual impact. We introduced an unbiased procedure for causal factor selection based on some intuitive statistical indices. This procedure is aimed at detecting among different potential factors the most discriminant ones in a given study area. Moreover, this step avoids generating too small and statistically insignificant spatial units by intersecting the factor maps. Finally, a validation procedure was applied based on the partition of the landslide inventory from multi-temporal aerial photo interpretation. Although encompassing some sources of uncertainties, the applied susceptibility assessment method provided a satisfactory and unbiased prediction for the Upper Orcia Valley. The results confirmed the efficiency of the selection procedure, as an unbiased step of the landslide susceptibility evaluation. Furthermore, we achieved the purpose of presenting a conceptually simple but, at the same time, effective statistical procedure for susceptibility analysis to be used as well by decision makers in land management
Cathodal transcranial direct current stimulation improves focal hand dystonia in musicians: A two-case study
Focal hand dystonia (FHD) in musicians is a movement disorder causing abnormal movements and irregularities in playing. Since weak electrical currents applied to the brain induce persistent excitability changes in humans, cathodal tDCS was proposed as a possible non-invasive approach for modulating cortical excitability in patients with FHD. However, the optimal targets and modalities have still to be determined. In this pilot study, we delivered cathodal (2 mA), anodal (2 mA) and sham tDCS over the motor areas bilaterally for 20 min daily for five consecutive days in two musicians with FHD. After cathodal tDCS, both patients reported a sensation of general wellness and improved symptoms of FHD. In conclusion, our pilot results suggest that cathodal tDCS delivered bilaterally over motor-premotor (M-PM) cortex for 5 consecutive days may be effective in improving symptoms in FHD
The potential of permanent gullies in Europe as geomorphosites
Geotourism is a useful way to educate societies in the field of geomorphology and natural hazards. Geosites, including geomorphosites, represent the basis for the development of this type of tourism. This study describes twelve representative gully regions within nine European countries. The characteristics of 42 permanent gullies, gully systems and badland landscapes are presented and a geotouristic assessment of these gullies was made, based on scientific, educational, functional and touristic indicators. This assessment demonstrates a large difference between the selected gully sites, particularly with regard to functional and tourist values. The geotouristic potential of gullies is the highest in Italy and Spain and the lowest in Romania and Latvia. In some countries, permanent gullies are not regarded as geotouristic attractions at all, while in others they constitute a significant element of their tourism development strategy. Based on the analysis of scientific values of the gully sites, educational lessons to be learned were identified that are mainly related to i) gullies as a geological window, ii) present-day geomorphological processes, and iii) stages of historical gully erosion reflecting past human-environment interactions. These must be part of a broader strategy for the development of geotourism in gully regions. Gullies are potential geosites within existing or planned geoparks. Values of gullies for other forms of tourism (active, cultural, nature), should be also emphasized
- …