Examinando por Materia "LANDSLIDES"

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    PublicaciónAcceso abierto
    Análisis de umbrales empíricos de lluvia para el pronóstico de movimientos en masa en el Valle de Aburrá, Colombia
    (2013-12-17) Aristizábal, E. (Edier); Gonzalez, T. (Tommy); Montoya, Juan David; Vélez, Jaime Ignacio; Martínez, H. (Hernán); Guerra, Alexánder
    Mass movements are the product of a progressive reduction of strength of slope geomaterials by human actions or natural processes, such as weathering, and triggered by external factors like rainfall or earthquakes. These events have demonstrated throughout history its destructive capacity, causing huge human and economic losses, especially in tropical and mountainous terrains, such as the Aburrá Valley. For this reason new studies on rainfall forecasting, real-time monitoring and the definition of critical rainfall thresholds have become essential tools for the implementation of early warning systems.
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    PublicaciónAcceso abierto
    Características, dinámica y causas del movimiento en masa del Barrio El Socorro (31 de mayo de 2008) en Medellín
    (2014-05-12) Aristizábal, E. (Edier)
    The article presents the causes and dynamic of the mass movement which occurred on May 31, 2008 in the higher part of San Pedro settlement, called Las Peñitas, Medellín. This tragic event left 27 dead people, 16 injured people and 20 houses destroyed of El Socorro settlement. This event with Rosellón (1927), Media Luna (1954), Santo Domingo (1974), Villatina (1987) and El Barro (2005) represents one of the most tragic events in the Aburrá Valley history. For the characterization of the area of the event previous work from different recognized, prestigious institutions was used; for the characterization, description of the predominant dynamics of the event and its causes ground evidence collected on the terrain and visual inspection the same day when it occurred were used, so that it did not change due to proper rescue works. The data of rainfall hydrometeorological stations of Empresas Públicas de Medellín (EPM) and Colombian Institute of Hydrology, Meteorology and Environmental Studies (IDEAM) were used, with the purpose of evaluating the influence of rain like triggering element. The mass movement was classified as simple rotational landslide on NE direction, with a longitude around 60 m, which due to high saturation levels, it changed to an debris flow moving 140 m ahead on SE direction, and finally the mass turned NE. Triggering causes are associated to geomechanical properties of soil and antecedent rainfall of previous 15 days and very intense rainfall event during May 30, when 83.3 mm fell down for just 2 hours and 30 minutes along the central part of the valley.
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    PublicaciónAcceso abierto
    La lluvia y los deslizamientos de tierra en Antioquia: análisis de su ocurrencia en las escalas interanual, intraanual y diaria
    (2014-05-07) Moreno-Ramírez, H. A. (Hernán Alonso); Vélez-Otálvaro, M. V. (María Victoria); Montoya, J. D. (Juan David); Rhenals-Garrido, R. L. (Remberto Luis)
    Relationship between rain and reported landslides in the department of Antioquia for the period of 1929 to 1999 is studied. The georeference of 405 landslides possibly produced by rain is made, on the region of study. The analysis of the occurrence of landslides during the warm and cold phases of ENSO phenomenon (El Niño Southern Oscillation) and the behavior of the intra-annual cycle are described. La Niña, on interannual scale, and the two rainiest periods in Andean zone, on intra-annual scale, contribute to increase the number of landslides per year. Analysis of precipitation data associated with historical landslide events in Antioquia has resulted in the identification of precipitation thresholds for the initiation of landslides and the possible combinations of preceding accumulated rain are described. The data indicated that the cumulative precipitation (15 days or more) influences the amount of subsequent 3-day precipitation that is needed to initiate ground movement. This study constitutes a first intend toward rain modeling and its influence on landslides occurrence which can help authorities on disasters prevention to declare states of emergency by conditions of threshold exceed. The analysis must be complemented having into account geotechnical, morphological, hydraulics, and anthropogenic conditions own to each place to have an integral view of the landslide phenomenon.
  • Miniatura
    PublicaciónAcceso abierto
    Sistema de alerta temprana por movimientos en masa inducidos por lluvia para el Valle de Aburrá, Colombia
    (2013-11-25) Aristizábal, E. (Edier); Gamboa, M. F. (Marco Fidel); Leoz, F. J. (Francisco Javier)
    The complex physical conditions of the Aburrá Valley coupled with high vulnerability levels led to scenarios with a high potential for human and economic losses upon the occurrence of natural phenomena such as mass movements, which represent 35 % of events occurring in the valley and 77 % of dead people. Due to these severe problems, since 2008, an early warning system for rainfall-induced landslides assisted by empirical rainfall thresfolds has been used. Early warning systems provide a rapid means for monitoring and communicating information about threats to a vulnerable community, so they are used primarily to protect lives, noting the possibility of occurrence of an event in advance, providing time to take action that can reduce the risk conditions. This paper describes the definition and model fit as well as presents the results of the validation of thresholds for the period 2004-2008.