Advances in Geosciences www.adv-geosci.net 1680-7340 1680-7359 22 4th EGU Alexander von Humboldt Conference "The Andes: Challenge for Geosciences" 2009 10.5194/adgeo-22-59-2009 http://www.adv-geosci.net/22/59/2009/ http://www.adv-geosci.net/22/59/2009/adgeo-22-59-2009.html http://www.adv-geosci.net/22/59/2009/adgeo-22-59-2009.pdf 59 65 2009-10-13 Mass movements in the Rio Grande Valley (Quebrada de Humahuaca, Northwestern Argentina): a methodological approach to reduce the risk G. Marcato marcato@irpi.cnr.it A. Pasuto F. R. Rivelli CNR-IRPI – National Research Council of Italy, Research Institute for Hydrological and Geological Hazard Prevention, C. so Stati Uniti 4, 35127 Padova, Italy Departamento de Ciencias Naturales, Universidad Nacional de Salta, Casilla De Correo 529, 4400 Salta, Argentina Slope processes such as slides and debris flows, are among the main events that induce effects on the Rio Grande sediment transport capacity. The slides mainly affect the slope of the Rio Grande river basin while debris and mud flows phenomena take place in the tributary valleys. In the past decades several mass movements occurred causing victims and great damages to roads and villages and therefore hazard assessment and risk mitigation is of paramount importance for a correct development of the area. This is also an urgent need since the Quebrada de Humahuaca was recently included in the UNESCO World Cultural Heritage. The growing tourism business may lead to an uncontrolled urbanization of the valley with the consequent enlargement of threatened areas. <br><br> In this framework mitigation measures have to take into account not only technical aspects related to the physical behaviour of the moving masses but also environmental and sociological factors that could influence the effectiveness of the countermeasures. <br><br> Mitigation of landslide effects is indeed rather complex because of the large extension of the territory and the particular geological and geomorphological setting. Moreover the necessity to maintain the natural condition of the area as prescribed by UNESCO, make this task even more difficult. <br><br> Nowadays no in-depth study of the entire area exists, therefore an integrated and multidisciplinary investigation plan is going to be set up including geological and geomorphological investigations as well as archaeological and historical surveys. The better understanding of geomorphological evolution processes of the Quebrada de Humahuaca will bridge the gap between the necessity of preservation and the request of safety keeping of the recommendation by UNESCO. % vor jede Referenz Amegual, R. and Zanettini, J. C.: Geologia de la quebrada de Humahuaca entre Uquia y Purmamarca (provincia de Jujuy), Revista de la Asociacion Argentina, 29(I), 30–40, 1974. Cencetti, C., Rivelli, F. R., and Tacconi, P.: Le colate detritiche nell'Arroyo del Medio (Provincia di Jujuy, Argentina nord-occidentale), Proc. of "INTERPRAEVENT 2004" (Riva del Garda, Trento, 24–28 maggio 2004), 1(III), 45–56, 2004. Cencetti, C., Rivelli, F. R., Tacconi, P., and Viglione, F.: La Quebrada de Humahuaca (Bacino del Rio Grande de Jujuy, Argentina nord-occidentale): caratteristiche di un bacino di ambiente andino, L'Universo, 4, 496–514, 2001. Chayle, W. and Aguero, P.: Caracteristicas de la remocion en masa en la Cuenca del Rio Grande (quebrada de Humahuaca, Jujuy), Revista del Instituto de Geologia y Mineria, San Salvador de Jujuy, Universidad Nacional de Jujuy, 7, 24–31, 1987. Gonzales Diaz, E. and Fauque, L. E.: Proveniencia del material componental del torrente de barro de "El Volcan", Quebrada de Humahuaca (Jujuy), Repubblica Argentina, Proc. of Decimo Congreso Geologico Argentino, San Miguel de Tucuman, III, 309–312, 1987. Harrington, H. J.: Las corrientes de barro (mud flow) del "El Volcan" Quebrada de Humahuaca, Jujuy, Asoc. Geol. Arg. Rev., 1(2), 149–165, 1946. Mon, R. and Salfity, J. A.: Tectonic evolution of the Andes of Northern Argentina, in: Petroleum basins of South America, edited by: Tankard, A. J., Suarez, R. S., and Welsink, H. J., American Association of petroleum Geologist Memoir, 62, 269–283, 1995. Monteverde, A. and Kittl, E.: Avalancha "El Volcan", Trabajo, 46, 891–956, 1946. Ramos, V. A., Turic, M. A., and Zuzek, A. B.: Geologia de las Quebradas de Huichara-Pocoya, Purmamarca y Tumbaya Grande en la Margen Derecha de la Quebrada de Humahuaca (provincia de Jujuy), revista de la Asociacion Geologica Argentina, 22(3), 209–221, 1967. Spalletti, L. A.: Sedimentologia de los cenoglomerados de Volcan. Provincia de Jujuy. Revista del Museo de La Plata, Universidad Nacional de La Plata, 66(VIII), 137–152. 1968. Turner, J. C. M.: The Andes of Northwestern Argentina, Geol. Rundsch., 59(3), 1028–1063, 1970.