Time response of a landslide to meteorological events

International audienceA landslide affecting two small villages located on the Northwestern Italian Apennines has been investigated since the year 2000 through the use of different equipment. A complex monitoring system has been installed in the area. The system includes several inclinometers, piezometers and a raingauge. An Automatic Inclinometric System (AIS) has been also installed that automatically performs measurements, twice a day, along the entire length of a pipe that is 45 m deep. This monitoring system has been set up to identify a methodology that allowed to deal with landslides, trying to predict their behaviour beforehand for warning purposes. Previous researches carried out in the same area for a period of about 7 months, in the year 2000, have allowed to identify a correlation between deep slope movements and rainfalls. In particular, it has been possible to determine the time lag needed for a rainfall peak to produce a corresponding peak of the landslide movements; this time lag was of 9 days. This result was possible because the AIS allows to obtain, as mentioned, daily inclinometric measurements that can be correlated with the recorded rainfalls. In the present report we have extended the analysis of the correlation between deep slope movements and rainfalls to a greater period of observation (2 years) to verify over this period the consistency of the time lag mentioned above. The time lag previously found has been confirmed. We have also examined the possibility to extend to the entire landslide body the correlation that has been found locally, analyzing the results of the remaining inclinometric tubes with traditional reading installed on the landslide and comparing them with the results of the AIS. The output of the tubes equipped with piezometric cells has also been analyzed. The relations existing among rainfalls, ground water level oscillations and the related slope movements have been explore

Preface Results of the open session on "Documentation and monitoring of landslides and debris flows" for mathematical modelling and design of mitigation measures, held at the EGU General Assembly 2009

The papers that are here presented and summarised represent the recent scientific contributions of some authors coming from different countries and working in the fields of monitoring, modelling, mapping and design of mitigation measures against mass movements. The authors had the opportunity to present their recent advancements, discuss each other needs and set forth future research requirements during the 2009 EGU General Assembly, so that their scientific contributions can be considered the result of the debates and exchanges that were set among scientists and researchers, either personally or during the review phase since that date. In this resume, the scientific papers of the special issue are divided according to different thematic areas and summarised. The most innovative scientific approaches proposed in the special issue, regarding the monitoring methodologies, simulation techniques and laboratory equipment are described and summarised. The obtained results are very promising to keep on future research at a very satisfactory level

Resonance production by neutrinos: I. J=3/2 Resonances

The article contains general formulas for the production of J=3/2 resonances by neutrinos and antineutrinos. It specializes to the P_{33}(1232) resonance whose form factors are determined by theory and experiment and then are compared with experimental results at low and high energies. It is shown that the minimum in the low Q^2 region is a consequence of a combined effect from the vanishing of the vector form factors, the muon mass and Pauli blocking. Several improvements for the future investigations are suggested.Comment: 10 pages, LaTeX, misprints corrected, 1 reference adde

Brief Communication: On the rapid and efficient monitoring results dissemination in landslide emergency scenarios: the Mont de La Saxe case study

Abstract. Straightforward communication of monitoring results is of major importance in emergency scenarios relevant to large slope instabilities. Here we describe the communication strategy developed for the Mont de La Saxe rockslide threatening La Palud and Entrèves hamlets in the Courmayeur municipality (Aosta Valley, Italy). Starting from the definition of actions and needs of the landslide management team, including scientists, technicians, civil protection operators, decision makers, and politicians, we show that sharing and disseminating ad hoc information simplifies the understanding of the landslide evolution, as well as the correct communication of the level of criticality

Decreasing flood risk perception in Porto Alegre – Brazil and its influence on water resource management decisions

Porto Alegre is the capital and largest city in the Brazilian state of Rio Grande do Sul in Southern Brazil with approximately 1.5 million inhabitants. The city lies on the eastern bank of the Guaiba Lake, formed by the convergence of five rivers and leading to the Lagoa dos Patos, a giant freshwater lagoon navigable by even the largest of ships. This river junction has become an important alluvial port as well as a chief industrial and commercial centre. However, this strategic location resulted in severe damage because of its exposure to flooding from the river system, affecting the city in the years 1873, 1928, 1936, 1941 and 1967. In order to reduce flood risk, a complex system of levees and pump stations was implemented during 1960s and 1970s. Since its construction, not a single large flood event occurred. However, in recent years, the levees in the downtown region of Porto Alegre were severally criticized by city planners and population. Several projects have been proposed to demolish the Mauá Wall due to the false perception of lack of flood risk. Similar opinions and reactions against flood infrastructure have been observed in other cities in Brazil, such as Itajaí and Blumenau, with disastrous consequences. This paper illustrates how the perception of flood risk in Porto Alegre has changed over recent years as a result of flood infrastructure, and how such changes in perceptions can influence water management decisions

Effects of nuclear re-interactions in quasi-elastic neutrino-nucleus scattering

The effects of nuclear re-interactions in the quasi-elastic neutrino-nucleus scattering are investigated with a phenomenological model. We found that the nuclear responses are lowered and their maxima are shifted towards higher excitation energies. This is reflected on the total neutrino-nucleus cross section in a general reduction of about 15% for neutrino energies above 300 MeV.Comment: 15 pages, 5 figures. Submitted to AstroParticle Physic

Regresión lasso bayesiana. Ajuste de modelos lineales penalizados mediante la asignación de priores normales con mezcla de escala

Uno de los desafíos más importantes del análisis estadístico en grandes volúmenes de da-tos es identificar aquellas variables que provean información valiosa, haciendo una selección de variables predictoras. La estimación Lasso (Least Absolute Shrinkage and Selection Ope-rator) para el modelo de regresión lineal puede ser interpretada desde el enfoque Bayesiano como la moda a posteriori cuando los coeficientes de regresión tienen distribución priori do-ble exponencial independientes. Al representar dicha distribución como una distribución Normal con mezcla de escala, es factible la construcción de un modelo jerárquico mediante la introducción de un vector de variables latentes, conjugando una distribución priori normal para los parámetros de regresión y prioris exponencial independientes para sus respectivas variancias. Mediante la implementación del algoritmo de simulación de Gibbs a partir de las distribuciones condicionales completas, se obtienen secuencias que permiten estimar cual-quier característica de interés de la distribución a posteriori de manera sencilla. La regresión Lasso Bayesiana tiene una enorme ventaja sobre el método clásico, dado que permite mejo-rar sustancialmente la inferencia, especialmente en el contexto de muchas variables predic-torasLa regresión Lasso Bayesiana es fácil de implementar y permite establecer intervalos de credibilidad para todos los parámetros estimados, incluida la variancia de los errores aleatorios. Al conseguir mediante GS una estimación de la distribución a posteriori de los parámetros, puede calcularse cualquier característica de interés bajo dicha distribución, como la esperanza a posteriori o la moda (\u1d737� ̂ \u1d43f�\u1d44e�\u1d460�\u1d460�\u1d45c�). Esto le otorga una enorme ventaja sobre el método clásico. En algunos casos, los valores de las estimaciones producidos por las regresiones Lasso estándar y bayesiana son muy similares. Dependiendo del método de optimización y si se utilizan o no aproximaciones, ambas estimaciones pueden coincidir. Los mecanismos de elección de \u1d706� que se proponen para la regresión Lasso Bayesiana, son aplicables para la regresión Lasso clásica y podrían ayudar a simplificar, otorgando mayor objetividad, la elección del mismo. Por otra parte, Casella (2008) muestra algunas extensiones del enfoque bayesiano para las regresiones Lasso y plantea la posibilidad de extender las consideraciones a modelos lineales generalizados, mediante algunas modificaciones metodológicas que no deberían requerir mayor esfuerzo computacional que desde el punto de vista clásicoOne of the most important challenges of statistical analysis in big data is to identify those variables that provide valuable information, making a selection of predictor variables. The Lasso (Least Absolute Shrinkage and Selection Operator) estimate for the linear regression model can be interpreted from the Bayesian approach as a posterior mode estimate when the regression parameters have independent double-exponential priors. Representing such distribution as a scale mixture of normals, it is feasible to construct a hierarchical model by introducing a vector of latent variables, with conjugate normal priors for the regression pa-rameters and independent exponential priors on their variances. By implementing the simula-tion Gibbs algorithm from complete conditional distributions, the obtained sequences allow to estimate any characteristic of interest based on the posterior distribution in a simple way. The Bayesian Lasso regression has a huge advantage over conventional methods; it sub-stantially improves inference, especially in the context of many predictor variablesFil: Allasia, María Belén - Facultad Ciencias Económicas y Estadística - Universidad Nacional de Rosario - ArgentinaFil: Allasia, María Belén - Facultad Ciencias Económicas y Estadística - Universidad Nacional de Rosario - ArgentinaFil: Quaglino, Marta Beatriz - Facultad Ciencias Económicas y Estadística - Universidad Nacional de Rosario - Argentin

A study of the double hadron neutrinoproduction on nuclei

The nuclear medium influence on the dihadron neutrinoproduction is investigated for the first time, using the data obtained with SKAT bubble chamber. An indication is obtained that the nuclear attenuation of the dihadron is more expressed for kinematically closest hadron pairs. The experimental data on the dihadron attenuation and on the ratio of the dihadron to single-hadron yields are compared with predictions of the two-scale string fragmentation model.Comment: 5 pages, 10 figure

Platelet Accumulation in Brain Microvessels in Fatal Pediatric Cerebral Malaria

The pathogenesis of fatal cerebral malaria (CM) is not well understood, in part because data from patients in whom a clinical diagnosis was established prior to death are rare. In a murine CM model, platelets accumulate in brain microvasculature, and antiplatelet therapy can improve outcome. We determined whether platelets are also found in cerebral vessels in human CM, and we performed immunohistopathology for platelet-specific glycoprotein, GPIIb-IIIa, on tissue from multiple brain sites in Malawian children whose fatal illness was severe malarial anemia, CM, or nonmalarial encephalopathy. Platelets were observed in 3 locations within microvessels: between malaria pigment and leukocytes, associated with malaria pigment, or alone. The mean surface area of platelet staining and the proportion of vessels showing platelet accumulation were significantly higher in patients with CM than in those without it. Platelet accumulation occurs in the microvasculature of patients with CM and may play a role in the pathogenesis of the diseas