María Victoria Soto Bäuerle

Carta geomorfológica de la sección central y occidental de la Región Metropolitana de Santiago

The geomorphologic chart of the western part of the Santiago Metropolitan Region was made considering a lito-morphologic units definition purpose, especially for the interpretation and classification of homogenous slope systems. The chart goal was the identification of homogenous slopes systems, in which the base of the morpho dynamic interpretation is sustained in the geologic nature of the materials. Structurally, the monoclinals reliefs are emphasized. Also, the lithological nature of the layers and not it position in the monoclinal is considered into the analysis of the medium and low mountain environment because, from a geodynamic point of view, they generally operate in a similar way. In the intrusive reliefs, remnants of erosional surfaces are distinguished. The notion of tenaces is also considered in the alluvial forms according to age, distinguishing between pleistocenic, holocenic, and indeterminated tenaces. As results, polygons of units of equal morphogenesis, lithologic and present geodynamics are generated.

Impacto en la geodinámica actual del valle de Nantoco, cuenca del río Copiapó, asociado a la reconversión productiva

The change in productive land use in the Copiapo valley began in the mid seventies, with an increase in the area planted with bush vines in the order of 236%. This has meant the introduction of significant morphological changes, exceeding in many places the morphodynamic thresholds, and generating impacts on the morphology dynamic. These impacts are significant in terms of increased vulnerability to mass removal occurring in episodes of heavy rains associated with the Nino years, with hazard for the resident population and agricultural workers, and in generating significant loss of infrastructure. We present the case of Nantoco basin, a sub-basin of the river Copiapo, which has experienced a notorious human intervention over the past three decades and which was analyzed in reference to its current morphodinamic behavior and the magnitude of its intervention.

Evaluación de la amenaza natural en ambiente semiárido, sustentada en la geomorfología y el modelamiento de índices topográficos. Salamanca, Región de Coquimbo, Chile

In the framework of territorial transformations in the Choapa river valley, we analyze the dynamics of geomorphic processes on basin scale. Special attention is given to changes due to human activities. In semiarid environments, both natural and anthropic landscapes have an immediate dynamic response to varying intensity and impact of rainfall events such as the phenomenon of El Nino. Intensive farming on hillsides, cones and glacis, is an emerging industry, inducing transformations of topography, vegetation and soil. We analyze the current geomorphology characterized by inherited forms, features and their process dynamics. Geomorphological and topographical models are applied to assess the relevant morphodynamics. The models yield information on the natural hazard of mass movements and fl uvially triggred erosion processes for the two study areas Salamanca and Panguesillo.

Características dinámicas de ensenadas estructurales de Chile central: Maitencillo-Cachagua y Papudo, Región de Valparaíso

The morphology of the coastline controlled by the tectonics and the morfoestructura has formed the irregular coast, with two small headland bay beaches. The variables that were analyzed - like relative position of the coast, refractive index, angle of curvature, type of beach dominated by waves and coastal forms - reflect the existence of two different coastal geographic units. The presence of two relatively contiguous but different beaches as far as its coastal form results in significant dynamic differences among them and to the interior of the same one. MaitencilloCachagua is transverse and intermediate beach, specifically transverse bar and beach, with the wavy high dynamics, that is translated in a strong condition of seasonal erosion of the beach and cliff; dynamic differences and wavy attack between the proximal, media and distal zone exist. Papudo is an oblique coast, clearly reflecting and in where the wavy energy presents a dynamics of low impact in the forms of the beach. Great seasonal and space differences in the dynamics of the dynamic patterns of the surge in the headland bay beach do not appear.

Assessment of Natural Hazards and Vulnerability in the Rio Copiapó Catchment: A case study in the ungauged Quebrada Cinchado Catchment

Intensive precipitations in desert areas are a very scarce phenomenon. Nevertheless, from time totime these events take place, as in 1997 in Southern Atacama Desert in Chile. The study area withinthe Copiapo catchment is intensively exploited by mining activities. However, in recent years thelandscape has been more and more used for agricultural purposes. Vineyards for grape production areirrigated with water from the Copiapo River and from groundwater aquifers. The agricultural activityis mainly focusing on the flat valley bottoms, as well as drainage lines that become active in casesof precipitation events. Thus, this study seeks to investigate the geo-hazards related to precipitationevents in order to quantify the risk for population and agricultural areas. Therefore, this study appliesa hydrological model calibrated in the ungauged basin of Quebrada Cinchado. The results demonstratethat events like the one on the 12.06.1997 generate intensive floods and related sediment dischargesthat endanger population and agricultural areas. The applied methodology allows quantification offlooding and mudflow risks, as well as to assess the spatial distribution of geo-hazards.

Aspectos geodinámicos de un paleoestuario del desierto marginal de Chile: Río Copiapó

In this investigation we analyze the evolution of forms that constitute the Copiapo River estuarine system during the past 30 years. Through photo interpreta...

Grado de persistencia morfológica de las formas estuariales del Maule (Chile Central) desde 1944 hasta 2011

Se estudia el grado de persistencia de las formas estuariales del Maule, considerando las diferencias de su estructura interna y la teoria sistematica acumulada. Para el reconocimiento de formas se uso cartografias historicas y fotointerpretacion cubriendo un lapso de 67 anos, terminado en 2011. El trabajo de terreno consistio en la descripcion de bancos, flechas y barras y su estado en el ultimo ano del periodo observado. La generalizada persistencia de los bancos del delta estuarial, sin cambios notables de forma y de tamano, indica que el balance entre erosion y progradacion fluvial opera bajo un regimen de retroalimentacion negativa, sin cambios fundamentales en el regimen fluvial. En este sentido, se puede admitir que esta forma esta controlada por un mecanismo de estabilidad fluvial, funcionando como delta estuarial de dominio fluvial. En contraste, la falta de las flechas que controlan la laguna estuarial y de las barras de la zona marina induce a concluir que estas formas son dominadas por oleaje de alta energia. Desde el punto de vista morfodinamico, las comparaciones entre el caso del Maule y otros deben hacerse separando las zonas de delta estuarial, laguna estuarial y marina.

Relación entre el cambio de uso del suelo en la cuenca del Aconcagua y su litoral arenoso correlativo: Chile central

Resumen es: En la cuenca del Aconcagua los procesos de modernizacion e intensificacion del uso de suelo se han traducido tanto en una reconversion agricola como en e...

Morfodinámica moderna de vertientes periglaciales de alta montaña, la cuenca del Río Cachapoal, Chile Central

Types of slopes and correlative basal deposits are studied in an Andean high valley of Central Chile, considering the slope sediment potential supply and its stability conditions. The morphotectonic dominion is characterized by detritic-volcanic and sedimentary formations, continental and marine, which appeared high affected by tectonic forces and strongly folded. Consequently, the slopes are analyzed like systems related to the folded structure, with variations both by the style and the arrangement of the layers in a monocline structure. The slopes basal fonns correspond to colluvial cones and talus, in different states of relative stabilization by vegetation. Only in the middle and higher parts of the valley, loose and consolidated pure gravitational deposits are observed. The differences founded in the present conditions of slope deposits, could be explained by the altitudinal differences and by the high level of faulting and folding of the rock layers, without to find a clear relation with the lithological composition. At the present, active avalanche processes dissect, reactivate and reworkthe basal deposits with a strong seasonal dynamics.

Características geomorfológicas de un sistema de glaciares rocosos y de su sustenatción en Chile semiárido

A rock glacier system is studied in an Andean high valley of the semi-arid region of Chile, basin of the Limari River, in order to recognize the different constituent forms, their dynamics, and the relationships with the surroudings and with the different evolutive stadia. The studied landforms are both glacial and periglacial. Their features include some of the evolutionary phases of rock glaciers. The landforms correspond to a tongue shape inactive rock glacier and to active talus rock glaciers. They can be simple, wavy or lobated. The importance of slope periglacial processes is established in relation with the present dynamic of these rock glacier features. Rock glacier morphogenetic conditions are directly linked to original processes, but also to periglacial mechanisms in their evolution, giving account of a complex system in wich a geomorphological continuum is demostrated. The changes in the level of activity of the system is due to a clear seasonality associated to a brief and cool winter and a large and temperate summer, characteristic of the Andes high mountains of the semi-arid Chilean region.