Search results for " survey."
showing 10 items of 1225 documents
Contribution of the largest events to suspended sediment transport across the USA
2010
This work analyses the contribution of the largest events to suspended sediment transport on the continental scale. The analysis is based on the United States Geological Survey (USGS) Suspended Sediment and Ancillary database. Data were obtained from 1314 catchments, comprising more than 2 500 000 daily events. The total number of days in the dataset amounts to 10 000 years. Catchments are of different sizes and belong to distinct climatic environments; they are distributed for the analysis according to USA hydrological divisions (HDs). The main objective of the research is to examine the effect of the n-largest event on the total suspended sediment load over recorded periods, and to discus…
Extraordinary sediment delivery and rapid geomorphic response following the 2008-2009 eruption of Chaitén Volcano, Chile
2016
U.S. Geological Survey Volcano Science Center SERNAGEOMIN's Programa de Riesgos Volcanicos Conicyt Fondecyt grants 1110609 1141064 11130671 Conicyt Fondap 15090013 Vamos Research Centre
Using post-flood surveys and geomorphologic mapping to evaluate hydrological and hydraulic models: The flash flood of the Girona River (Spain) in 2007
2016
This paper analyzes the Girona River (Spain) flash flood, occurred on the 12th of October 2007, combining hydrological and hydraulic modeling with geomorphologic mapping and post-flood survey information. This research aims to reproduce the flood event in order to understand and decipher the flood processes and dynamics on a system of prograding alluvial fans. The hydrological model TETIS was used to characterize the shape and dimension of the October 2007 Girona River hydrograph. Subsequently, the flood event was reproduced using the free surface flow module of the model RiverFlow2D. The combination of hydrological and hydraulic models was evaluated using post-flood surveys defining maximu…
Characterisation of submarine groundwater discharge offshore south-eastern Sicily
2005
A complex approach in characterisation of submarine groundwater discharge (SGD) off south-eastern Sicily comprising applications of radioactive and non-radioactive tracers, direct seepage measurements, geophysical surveys and a numerical modelling is presented. SGD fluxes in the Donnalucata boat basin were estimated by direct seepage measurements to be from 4 to 12Ls(-1), which are comparable with the total SGD flux in the basin of 17Ls(-1) obtained from radon measurements. The integrated SGD flux over the Donnalucata coast estimated on the basis of Ra isotopes was around 60m(3)s(-1) per km of the coast. Spatial variations of SGD were observed in the Donnalucata boat basin, the average (222…
Caries Prevalence Evolution and Risk Factors among Schoolchildren and Adolescents from Valencia (Spain): Trends 1998–2018
2020
The aim of this study was to determine the caries status and risk factors in the schoolchildren of Spain&rsquo
QoS Mechanisms for IEEE 802.11 Wireless LANs
2004
Currently the Internet provides users with access to information across the world using IP technology. Until now most access points to the Internet have been fixed stations at given locations, but with increasing sales of mobile devices, mobility has become a major trend. Therefore, the Internet is becoming more and more heterogeneous due to the recent explosion of wireless networks. The IEEE 802.11 wireless LAN (WLAN) is the most widely used WLAN standard nowadays. Currently the IEEE 802.11 standard specifies an over-the-air interface between wireless devices. However, QoS services over this technology are still being defined aiming to provide support to multiple applications. Thus, a larg…
Development and evaluation of image-series for portion size estimation in dietary assessment among adults
2021
AbstractPortion size images are advantageous in dietary assessment. The aim of the present study was to develop and validate new culturally specific image-series for portion size estimation to be used in a new Norwegian version of a British web-based dietary assessment tool (myfood24). Twenty-three image-series of different foods, each containing seven portion size images, were created and validated in a group of adults (n41, 58 % female) aged 19–44 (median 23), out of which 63 % had higher (tertiary) education. The participants compared 46 portions of pre-weighed foods to the portion size images (1886 comparisons in total). Portion size estimations were either classified as correct, adjace…
Les exclus de la mobilité : de l'observation à la décision
2014
In contemporary societies, mobility is considered as a social norm necessary for integration. Conversely, immobility is often seen as the opposite. Therefore, it is associated with a significant risk of exclusion. An approach in terms of exclusion involves a sociological orientation. Nevertheless, this thesis follows a geographical approach. Thus, a first question emerges from this disciplinary position: immobility is it a geographical object? Furthermore, it is possible to consider the mobility and immobility as equivalent and not opposed. This means that their impact may not be reversed. This position engages a second question: the relationship between immobility and exclusion is it legit…
Brancati su Pirandello e il pirandellismo
2019
Nel romanzo breve "Sogno di un valzer" uscito a puntate su “Quadrivio”, dal 5 giugno al 14 agosto 1938, Vitaliano Brancati mette in scena, tra osservazione dei luoghi e rilevamento di costume, un’umanità fuori misura, continuamente in bilico tra realtà e sogno. A Caltanissetta (Nissa) la città nel cui Istituto magistrale lo scrittore, voltate le spalle alla Roma fascista, è venuto a insegnare, personaggi non appariscenti, insignificanti, che tuttavia covano desideri, si arrovellano in domande metafisiche. Prende così forma il leitmotiv delle critica al pirandellismo che più volte con ironia sottile affiora negli scritti brancatiani. Il saggio mostra come esso si intrecci con la comicità sul…
The probabilities of selection of first and second stage units in the Time Location Sampling (TLS) design on incoming tourism in Sicily and Sardinia
2011
The present work aims to illustrate the criteria used for the determination of probabilities of selection of first and second stage units, given the available information, within the TLS design implemented for the survey of the Relevant National Interest Project (PRIN) on mobility of regional incoming tourism in Sicily and Sardinia. First and second stage units selection probabilities are necessary for the implementation of Hansen-Hurwitz class estimators for the estimation of the average number of stops made by tourists in Sicily, for the estimation of the share of un-observed tourism, and for the sampling errors associated.