623 research outputs found
Meteorological forecasting for the European Southern observatory in Chile
The potential of numerical weather prediction to supply a useful support to flexible scheduling of astronomical observations is investigated. We applied some common tools presently used in numerical meteorology at regional scale in order to evaluate the ability to forecast local meteorological conditions (cloud cover, air temperature and wind speed) at Cerro Paranal and Cerro La Silla in Chile,
where telescopes of ESO (the European Southern Observatory) are sited. The first part of this paper is devoted to evaluating the accuracy of analysis and forecasts of the ECMWF (European Center for Medium-range Weather Forecast) general circulation model for ESO needs. With this aim, analysis and 24-48 hour forecasts from ECMWF are systematically compared with observations at the ground
meteorological stations of Paranal and La Silla, and with vertical profiles of radiosounding launches at Antofagasta and Quintero. The second part of this paper is aimed at improving the ECMWF forecasts at telescope sites by means of Kalman filter statistical post-processing and meteorological limited area modeling. Encouraging results are obtained concerning temperature, whereas much less
satisfactory results are obtained for wind field and cloud cover. The most critical aspects of atmospheric dynamics affecting the local forecast are discussed within the
limits of available information
Modelling a cell tower using SFM: automated detection of structural elements from skeleton extraction on a point cloud
The surveying and management of telecommunication towers poses a series of engineering challenges. Not only they must be regularly inspected for the purpose of checking for issues that require maintenance interventions, but they are often sub-let by their owners to communication companies, requiring a survey of the many (several thousand per company) installed appliances to check that they respect the established contracts. This requires a surveying methodology that is fast and possibly automated. Photogrammetric techniques using UAV-mounted cameras seem to offer a solution that is both suitable and economical. Our research team was asked to evaluate whether, from the information acquired by small drones it was possible to obtain geometric information on the structure, with what degree of accuracy and what level of detail. The workflow of this process is naturally articulated in three steps: the acquisition, the construction of the point cloud, and the extraction of geometries. The case study is a tower carrying antennas owned by several operators and placed in the industrial district of Cagliari. The article examines the problems found in modelling such structures using point clouds derived from the Structure-from-Motion technique, in order to obtain a model of nodes and beams suitable for the reconstruction of the structure's geometric elements, and possibly for a finite elements analysis or for populating GIS and BIM, either automatically or with minimal user intervention. In order to achieve this, we have used voxelization and skeleton extraction algorithms to obtain a 3D graph of the structure. The analysis of the results was carried out by varying the parameters relating to the voxel size, which defines the resolution, and the density of the points contained inside each voxel
Protocol for the economic evaluation of a complex intervention to improve the mental health of maltreated infants and children in foster care in the UK (The BeST? services trial)
Introduction: Children who have experienced abuse and neglect are at increased risk of mental and physical health problems throughout life. This places an enormous burden on individuals, families and society in terms of health services, education, social care and judiciary sectors. Evidence suggests that early intervention can mitigate the negative consequences of child maltreatment, exerting long-term positive effects on the health of maltreated children entering foster care. However, evidence on cost-effectiveness of such complex interventions is limited. This protocol describes the first economic evaluation of its kind in the UK.
Methods and analysis: An economic evaluation alongside the Best Services Trial (BeST?) has been prospectively designed to identify, measure and value key resource and outcome impacts arising from the New Orleans intervention model (NIM) (an infant mental health service) compared with case management (CM) (enhanced social work services as usual). A within-trial economic evaluation and long-term model from a National Health Service/Personal Social Service and a broader societal perspective will be undertaken alongside the National Institute for Health Research (NIHR)–Public Health Research Unit (PHRU)-funded randomised multicentre BeST?. BeST? aims to evaluate NIM compared with CM for maltreated children entering foster care in a UK context. Collection of Paediatric Quality of Life Inventory (PedsQL) and the recent mapping of PedsQL to EuroQol-5-Dimensions (EQ-5D) will facilitate the estimation of quality-adjusted life years specific to the infant population for a cost–utility analysis. Other effectiveness outcomes will be incorporated into a cost-effectiveness analysis (CEA) and cost-consequences analysis (CCA). A long-term economic model and multiple economic evaluation frameworks will provide decision-makers with a comprehensive, multiperspective guide regarding cost-effectiveness of NIM. The long-term population health economic model will be developed to synthesise trial data with routine linked data and key government sector parameters informed by literature. Methods guidance for population health economic evaluation will be adopted (lifetime horizon, 1.5% discount rate for costs and benefits, CCA framework, multisector perspective).
Ethics and dissemination: Ethics approval was obtained by the West of Scotland Ethics Committee. Results of the main trial and economic evaluation will be submitted for publication in a peer-reviewed journal as well as published in the peer-reviewed NIHR journals library (Public Health Research Programme).
Trial registration number: NCT02653716; Pre-results
A meteo-hydrological forecasting chain: performance of the downscaling and rainfall-runoff steps in a small catchment
Forecasting ground effects of severe meteorological events with an adequate lead time is fundamental for civil protection scopes and is therefore an important challenge for the scientific community. The paper focuses on the performance of some steps of a meteo-hydrological forecasting chain that can be applied in small watersheds to assess hydrological risk deriving by an intense storm predicted at the large meteorological scale. The proposed procedure integrates large-scale rainfall fields, as those produced by numerical weather prediction (NWP) models, with statistical rainfall downscaling and hydrological modelling. More in details, assuming a large scale rain rate as the input of the process, the forecasting chain produces an ensemble of hydrographs that are post-processed in order to give a probabilistic representation of mean streamflow maxima for different time windows. The outcome of this procedure can be thus applied to assess the risk that some critical streamflow thresholds may be exceeded. The procedure has been tested on more than one thousand recorded events in the Araxisi catchment in Sardinia, Italy. Results and performances are presented and discussed
Integrating uavs and canopy height models in vineyard management: A time-space approach
The present study illustrates an operational approach estimating individual and aggregate vineyards’ canopy volume estimation through three years Tree-Row-Volume (TRV) measurements and remotely sensed imagery acquired with unmanned aerial vehicle (UAV) Red-Green-Blue (RGB) digital camera, processed with MATLAB scripts, and validated through ArcGIS tools. The TRV methodology was applied by sampling a different number of rows and plants (per row) each year with the aim of evaluating reliability and accuracy of this technique compared with a remote approach. The empirical results indicate that the estimated tree-row-volumes derived from a UAV Canopy Height Model (CHM) are up to 50% different from those measured on the field using the routinary technique of TRV in 2019. The difference is even much higher in the two 2016 dates. These empirical findings outline the importance of data integration among techniques that mix proximal and remote sensing in routine vineyards’ agronomic practices, helping to reduce management costs and increase the environmental sustainability of traditional cultivation systems
Incidence of grapevine trunk diseases on four cultivars in Sardinia, Southern Italy
Esca proper and Botryosphaeria dieback are among the most widespread Grapevine trunk diseases (GTDs), characterized by similar decline symptoms. In the present work, chronic, apoplexy and death symptoms were analysed separately in four vineyards and four different cultivars, on more than 1,000 vines per cultivar, taking into account ten-year annual surveys. The cumulative incidence of plants with chronic symptoms (CHR) reached high values on 'Sauvignon Blanc' (81.9 %), 'Cabernet Sauvignon' (79.4 %) and 'Cannonau' (66.5 %), but it was low on 'Merlot' (25.1 %). 'Sauvignon Blanc' showed the highest cumulative incidence of apoplectic events (23.1 %) and dead cordons (49.2 %), while 'Cannonau' had the greatest number of dead plants (28.8 %). In each symptom category, incidence among cultivars differed significantly according to χ2 test at P ≤ 0.05. Annual incidence of foliar symptoms fluctuated over ten years (ranging from 0.9-9.5 % in 'Merlot' to 6.3‑59.1 % in 'Cabernet Sauvignon'), mostly with regard to CHR. On average, every year only 33.9 % of plants showing CHR had expressed symptoms in the previous year, while 48.6 % did not show symptoms the following year. Conversely, most of the plants exhibiting apoplexy or death were symptomatic the previous year. According to Tuckey HSD test (P ≤ 0.05) 'Merlot' had the highest incidence of plants showing CHR symptoms for the first time (72.1 %) and of apparently recovered plants (76.3 %), while 'Cabernet Sauvignon' exhibited the highest incidence of plants showing CHR symptoms also the previous year (50.0 %). The 'Cabernet Sauvignon' attitude to show chronic symptoms with a certain continuity was also confirmed by the low incidence of plants with hidden symptoms (lack of symptoms in previously symptomatic vines). On the contrary, the incidence of acute symptoms (apoplectic events and dead plants) was quite low on 'Cabernet Sauvignon'. The present study confirms that GTD incidence is influenced by cultivar. All the cultivars assessed were susceptible, but with differences in intensity, type (chronic or acute) and fluctuation of symptoms. It cannot be excluded, however, that besides the genotype also external factors, as the vigour conferred by the type of soil or the combination with the rootstock, may have influenced the results
Metodi geofisici per la caratterizzazione degli ammassi rocciosi
Vengono illustrati i risultati che si possono ottenere nello studio delle caratteristiche fisiche degli ammassi rocciosi con le diverse tecniche grofisich
Regional climate models' performance in representing precipitation and temperature over selected Mediterranean areas
This paper discusses the relative performance of several climate models in providing reliable forcing for hydrological modeling in six representative catchments in the Mediterranean region. We consider 14 Regional Climate Models (RCMs), from the EU-FP6 ENSEMBLES project, run for the A1B emission scenario on a common 0.22° (about 24 km) rotated grid over Europe and the Mediterranean region. In the validation period (1951 to 2010) we consider daily precipitation and surface temperatures from the observed data fields (E-OBS) data set, available from the ENSEMBLES project and the data providers in the ECA&D project. Our primary objective is to rank the 14 RCMs for each catchment and select the four best-performing ones to use as common forcing for hydrological models in the six Mediterranean basins considered in the EU-FP7 CLIMB project. Using a common suite of four RCMs for all studied catchments reduces the (epistemic) uncertainty when evaluating trends and climate change impacts in the 21st century. We present and discuss the validation setting, as well as the obtained results and, in some detail, the difficulties we experienced when processing the data. In doing so we also provide useful information and advice for researchers not directly involved in climate modeling, but interested in the use of climate model outputs for hydrological modeling and, more generally, climate change impact studies in the Mediterranean region
Importance of plants with extremely small populations (Psesps) in endemic-rich areas, elements often forgotten in conservation strategies
The distribution of the threatened fern Ophioglossum vulgatum L., a plant with extremely small populations (PSESPs) in Sardinia, is characterized by small disjunct populations with only a few individuals, and little is known about its status in the wild. To provide information for the conservation of O. vulgatum and with the aim to develop an in situ conservation strategy, we investigated its distribution, population size, and habitat. Field surveys confirmed that the species grows in only five localities. Two representative populations were selected for this study (Funtanamela and Gedili), and in each population, all plants were mapped and monitored monthly from April to August over an 8-year period. During the study, the populations had a very low number of reproductive plants and the populations appeared to be in decline, with the total number of plants per population slightly decreased in Gedili while a sharp reduction was recorded in Funtanamela due to wild boar threat. A fence was built in order to protect the site from further damage, but no noticeable signals of recovery were observed. The most urgent conservation requirement for this species is to preserve the threatened habitat of the remnant populations. Further field surveys and research are also required for an improved understanding of the species’ status
Life Cycle Assessment (LCA): New poplar clones allow an environmentally sustainable cultivation
In Italy 72 poplar clones ( Populus spp.) are registered for commercialization. They were selected for fast growth, stem shape and disease resistance. The new selections (named MSA) includes genotypes with very high resistance to all the main diseases and to one insect, Phloeomizus passerinii (Sign.). Fast growth and disease resistance allow to produce wood with low environmental and economic costs; for this reason in some Italian Regions the introduction of a percentage of these clones in poplar stand is mandatory to obtain funding for their establishment (Rural Development Plan). To better understand the environmental advantages deriving from the use of these clones, in comparison with the old genotypes (particularly ‘I-214’), a ‘Life Cycle Assessment’ approach was applied considering as impact indicator the CO 2 equivalent emissions; from stoolbed to commercial stand, primary data were collected from an Italian experience. Firstly with the Inventory Analysis all the raw material, energy, wastes and emissions related were collected for each cultivation phase. The Analysis showed a reduction of 9% of CO 2 eq. ha -1 emitted, growing MSA instead of ‘I-214’. Considering the emissions per volume of wood, ‘I-214’ requests 47.5 kg CO 2 eq. per m 3 , compared with MSA that request 36.6 kg CO 2 eq. per m 3
- …