Carmen Paz Castro Correa

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.

Geomorfología aplicada a la evaluación de amenazas de origen natural en la zona sur de la comuna de Pichilemu, Región de O’Higgins, Chile

Se analiza el area costera comprendida entre el headland de Punta de Lobos y la localidad de Cahuil, en Chile central identi cando las amenazas de origen natural y evaluando la susceptibilidad de ocurrencia de eventos hidrometeorologicos que generen inundaciones uviales. Se analizaron los procesos morfodinamicos activos y factores condicionantes a traves de cartografia geomorfologica, recoleccion de datos historicos, estadisticas pluviometricas, analisis hidrologicos y multitemporal de fotografias aereas e imagenes satelitales. Los resultados obtenidos establecen que existen condiciones de amenaza (magnitud, recurrencia, alcance espacial), asociadas a procesos de remociones en masa, licuefaccion y erosion de suelos, inundaciones uviales, marejadas y tsunamis. La metodologia fue validada con trabajo de terreno en los anos 2013 y 2015.

Evaluación de la pérdida de suelo, asociada al proceso de expansión urbana y reconversión productiva: Caso: comunas de Los Andes, Quillota y Concón, valle del Aconcagua

The assessment of soil degradation in Los Andes, Quillota and Concon municipalities, which represents the morphoclimatic environments of Aconcagua Valley, was identified through the Erosion Respones Units (ERUs). Subsequently, the soil loss was quantified through the Universal Soil Loss Equation (USLE) in microbasins, and timely simulations were made for two different scenarios, representing the implementation of soil conservation practices. On the other hand, quality indicators were used to quantify the degradation produced in the last decade on the bottom part of the valley. Results show a clear degradation of agricultural valley soils as a result of both endogenous and exogenous factors. Among them, the topography and vegetation coverage were found to be relevant, in addition to the impact of socio-economic dynamics. Agricultural soils from the bottom part of the valley show the highest vulnerability of the study, due to intense territorial changes in the last decades.

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...

Procesos de reestructuración urbana y niveles de vulnerabilidad a amenazas naturales en una ciudad de tamaño medio: La Serena, Chile

The urban research in Latin America has been concentrated on the top cities of the national settlement system. Among the issues of research are the social spatial effects, environmental and functional effects and particularly those referred to unequal, segregated and sprawl urban growth. The former issues mentioned are thought to be present in other cities as well, particularly in middle size cities of the urban systems thus playing an important role on spatial structuring at regional scale. The present paper main contribution refers to increasing the knowledge of the changing processes of Chilean middle sizes cities at a regional scale context. The specific study area is the capital city of Coquimbo region named La Serena. It is located in the northern central part of Chile. Recent research results show that this city tends to reproduce largest cities structuring and spatial processes, as well as the modification of population distribution density model, centrality structures, urban sprawl growth and social segregation increasing.

Susceptibilidad erosiva asociada al proceso de reconversión agrícola productiva, cuenca semiárida de Quillota. V Región de Valparaíso, Chile

espanolEn el marco del proceso de reconversion agricola productiva que ha experimentado la zona norte y centro del pais, se han establecido plantaciones de frutales en laderas de cerros y zonas de piedemonte; muchas veces sobrepasando los umbrales morfodinamicos aconsejables para el uso productivo. Esta practica esta otorgando a los territorios una condicion de mayor susceptibilidad erosiva, influyendo tambien en la perdida de calidad del suelo en los fondos de valles. Mediante el modelo de Unidades de Respuesta a la Erosion ?ERU? de Marker et al. 2001, metodo de caracter cualitativo que arroja niveles de susceptibilidad erosiva a partir de la consideracion conjunta y ponderada de las variables del sistema que influyen en la problematica, se analizo la erodabilidad en funcion de los patrones de ocupacion de este proceso de reconversion en la cuenca semiarida de Quillota (32o52?0?S 71o16?0?O). Los resultados arrojaron que superficies reconvertidas agricolamente y asociadas a los sistemas de vertientes y conos aluviales obtienen una erodabilidad baja cuando poseen caracteristicas de mayor densidad vegetal, menor pendiente y exposicion sur, mientras que las areas de mayor erodabilidad presentaron densidades vegetales bajas, pendientes pronunciadas y exposiciones norte. En las superficies de menor y mayor erodabilidad se hallaron practicas de manejo como camellones a favor de la pendiente, terrazas en curvas de nivel y laderas con vegetacion nativa; siendo los camellones aquellos que provocaron la mayor susceptibilidad erosiva EnglishIn the context of the agricultural productive conversion processes that have taken place in the northern and central regions of the country, fruit tree plantations have been established on hillsides and piedmont zones, often trespassing the morphodynamic thresholds advisable for productive use. This practice is granting the land a state of a greater susceptibility to erosion. By means of the model of Erosion Response Units (ERU) �Marker et al. 2001� a qualitative method that provides levels of erosion susceptibility considering the joint and analyzed variables of the system that influence this problem- the phenomenon of erodibility was examined based on the patterns of the process of conversion in the semiarid catchment of Quillota (32o52�0�S 71o16�0�W). The results showed that the soil �that was agriculturally converted associated to slop systems and alluvial cones� obtained low erodibility when they possess such characteristics as major vegetable density, minor gradient and south exposure; whereas the areas of major erodibility presented lower vegetable density, major gradient and north exposure. On the surfaces with minor and major erodibility handling practices like farming ridges in direction to the slope, contour terraces and hillsides with native vegetation were found; being the farming ridges those that caused the greatest erosion susceptibility

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.