El clima de la vertiente del Pacífico de los Andes Centrales y sus implicaciones geomorfológicas El clima de la vertiente del Pacífico de los Andes Centrales y sus implicaciones geomorfológicas

Climate studies are of main importance to explain the external geodynamics of the Pacific Basin of the Central Andes between 15°S and 19°S. This is because the processes by which the relief modeling or morphogenesis develop are controlled by pluviometric variables and phyto stabilization. Moreover, the internal geodynamic of the region is related to the climatic conditions that determine the amounts of sediments aported to the Ocean basin (Kulm et al. 1977), affecting the erosion rate by subduction in the plane of contact between the tectonic plates and the composition of the magazas formed below the Andean erogene. In this paper we analyze the climatic effects in the external geodynamics, within a theoric framework that considers a morphoclimatic system as a set formed by the morphogenetic agents and processes that work the relief modeling in a territory, in function of its bioclimatic characteristics; and a morphoclimatic dominion is the spatial environment where a specific morphoclimatic system develops. First, we present the clima of the Central Andes, the factors that control its mean configuration and its main characteristics with diagrams made from the pluviometric data collected in a series of stations regularly distributed in the region. Second, we differentiate two climatic dominions, one in the Altiplano, related to Amazonia precipitations and the other at the Pacific side, associated to the anticyclonic permanency in the western cordillera. Third, we propose a subdivision of the western fa ade of the cordillera in altitudinal intervals or bioclimatics sections using bioindicators such as the vegetation absence or presence with altitudinal change. Fourth, we give a new division in altitudinal intervals or morphoclimatic zones, using the existence of some geoindicators, such as the endemic geomorphic units of each morphoclimatic zone. El estudio del clima es imprescindible para explicar la geodinámica externa en la vertiente del Pacífico de los Andes Centrales, entre 15°S y 19°S), debido a que los procesos mediante los cuales se desarrolla el modelado del relieve o morfogénesis están controlados por las variables termo-pluviométricas y la fito-estabilización. Además, la geodinámica interna de la región se encuentra igualmente relacionada con las condiciones climáticas, que determinan la cuantía del aporte de sedimentos a la fosa oceánica (Kulm et al. 1977), afectando a la tasa de erosión por subducción en el plano de contacto entre las placas y a la composición de los magazas que se forman bajo el erógeno andino. En esta ponencia se analizan lo