Octavio RojasUniversity of Concepción · Centro de Ciencias Ambientales EULA - Chile
Octavio Rojas
PhD Environmental Sciences
Departamento de Planificación Territorial y Sistemas Urbanos
About
57
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Introduction
Dr. en Ciencias Ambientales. Soy profesor del Departamento de Planificación Territorial y Sistemas Urbanos de la Facultad de Ciencias Ambientales y Centro EULA-Chile. Mis líneas de investigación se centran el campo de la Geografía Física, análisis de riesgos hidroclimáticos, inundaciones, evaluación del riesgo socionatural y servicios ecosistémicos de regulación. Mis publicaciones han analizado el nexus de los desastres, reconstrucción y la Planificación Urbana.
Additional affiliations
April 2015 - July 2020
April 2010 - January 2015
Education
March 2011 - March 2015
Publications
Publications (57)
Una revisión bibliográfica de inundaciones fluviales históricas en el período 1574-2012 a través de diferentes publicaciones, permite analizar, explicar y sistematizar causas o factores detonantes, periodos de recurrencia, distribución y efectos geográficos de las inundaciones acaecidas en Chile continental. Según el factor detonante se identifican...
Urban flooding is an increasing problem in developing countries, thus understanding flood dynamics is necessary to establish guidelines on urban development and flood management. This paper studied the lower reaches of the Andalien River basin, situated on the coast of the Greater Concepcion Metropolitan Area (CMA), the second most urbanized area i...
Implementing disaster risk reduction (DRR), climate change adaptation and mitigation (CCA/M), and sustainable development are key to increasing community resilience to pressing climate change risks. Barriers to grassroots implementation of national and international policies are inexorably linked to local contexts and in-depth understanding is cruc...
A worldwide increase in flooding due to climate change and population growth in exposed areas is expected, especially in coastal areas; therefore, nature-based solutions (NBS) for risk reduction are necessary to increase the resilience of cities, particularly in developing countries, which usually lack large budgets for structural measures but have...
Freshwater availability has decreased alarmingly worldwide, with agriculture playing a vital role in this trend. The assessment of the agricultural water footprint (WFagricultural) and virtual water flows (VWF) is fundamental not only in local water resources management and protection, but also in our understanding of the synergies between local wa...
The global increase in human population is driving a continuous conversion of land to anthropogenic uses. This is a major threat to lotic ecosystems worldwide, as it compromises the biotic integrity and health of rivers and streams. Studies in the northern hemisphere have shown that the effects of urbanization on fish assemblages include decrease a...
The installation of hydroelectric plants has generated multiple environmental impacts on the world’s river systems. In central Chile, the impacts of hydroelectric reservoir operation have been documented in ecological and hydrologic regime terms. This investigation assesses the changes in channel morphology, vegetation distribution, and flows in th...
Coastal wetlands areas are heterogeneous, highly dynamic areas with complex interactions between terrestrial and marine ecosystems, making them essential for the biosphere and the development of human activities. Remote sensing offers a robust and cost-efficient mean to monitor coastal landscapes. In this paper, we evaluate the potential of using h...
Groundwater (GW) use has intensified in recent decades, threatening the ecological integrity of groundwater-dependent ecosystems (GDEs). The study of GDEs is limited; therefore, integrated, interdisciplinary environmental approaches that guarantee their monitoring and management amid current climate and anthropogenic changes are needed. A new geosp...
Preparedness against floods in nearly pristine socio-hydrological systems The relations between preparedness and psycho-social attributes of people and communities exposed to river floods in a nearly pristine socio-hydrological system were investigated, applying hydrological-hydraulic analysis of flood risk in combination with results from a survey...
The coastal evolution of the microtidal Tubul-Raqui wetland in south-central Chile (36° S), which historically has been affected by large earthquakes and tsunamis, particularly the 1960 (Mw = 9.5) and 2010 (Mw = 8.8) subduction earthquakes and their associated tsunamis, is analyzed. Historical aerial photographs and topographic and bathymetric surv...
Groundwater (GW) is the primary source of unfrozen freshwater on the planet and in many semi-arid areas, it is the only source of water available during low-water periods. In north-central Chile, there has been GW depletion as a result of semi-arid conditions and high water demand, which has unleashed major social conflicts, some due to drought and...
Tsunamis are among the most significant hazards in coastal settlements. Mitigation measures have been focused mainly on physical aspects, and few studies have addressed vulnerability and resilience in a multidimensional approach. The main objective of the present work is to assess changes in vulnerability and, consequently, risk, considering a time...
Amid the growing population, climate change and decreasing water availability, water resources planning faces the challenge of achieving efficient and equitable water use, mainly in food production, its greatest consumer. The sustainability of agricultural water consumption in the Cachapoal River basin (34°S 71°O) is assessed using the blue (WFSblu...
Las pérdidas económicas de los desastres en las últimas décadas se han incrementado como resultado del desarrollo económico y probablemente con el aumento del número de eventos meteorológicos extremos (Haer, 2017). En tal sentido, los sistemas de alerta temprana son una herramienta para fortalecer los niveles de preparación vinculados a la gestión...
Coastal wetlands are ecosystems that provide multiple benefits to human settlements; nonetheless, they are seriously threatened due to both a lack of planning instruments and human activities associated mainly with urban growth. An understanding of their functioning and status is crucial for their protection and conservation. Two wetlands with diff...
Las inundaciones fluviales son un problema creciente en zonas costeras debido a las profundas transformaciones ambientales que tienen lugar desde mediados del siglo XX. En cuencas costeras de la región mediterránea de Chile (32°-38° S) los esfuerzos para mitigar los procesos de inundación se han centrado en medidas estructurales. La presente invest...
Amid the growing population, climate change and decreasing water availability, water resources planning faces the challenge of achieving efficient and equitable water use, mainly in food production, its greatest consumer. The sustainability of agricultural water consumption in the Cachapoal River basin (34°S 71°O) is assessed using the blue (WFSblu...
Understanding water consumption is crucial for sustainable management of water resources. Under climate change scenarios that project highly variable water availability, the need for public policies that assure efficiency and equity in water resources is increasing. This work analyzes the case of the Cachapoal River agricultural basin (34°S 71°W),...
Inundaciones fluviales y anegamientos son procesos recurrentes en la comuna de San Pedro de la Paz, detonados principalmente por la ocurrencia de precipitaciones intensas. Las zonas de inundación fueron delimitadas mediante modelación hidráulica, mientras que las áreas susceptibles de presentar anegamientos fueron determinadas mediante 3 factores f...
Coastal floods have become a serious problem on a global scale, increasing in frequency or magnitude due to natural conditions, and exacerbated by socioeconomic factors. This investigation analyzes the role of tides and average sea levels on the development and intensity of flooding in the lower section of the Andalién River, located toward the sou...
Natural disasters can cause abrupt disturbances in coastal wetlands, affecting the social perception of ecosystem services (ES). The Tubul-Raqui coastal wetland is one of the most important wetlands in south-central Chile. Rich in biodiversity, these wetlands provide ES to a population of 2238 inhabitants. The recent MW = 8.8 earthquake of 2010 cau...
A large earthquake and tsunami took place in February 2010, affecting a significant part of the Chilean coast (Maule earthquake, Mw of 8.8). Dichato (37◦ S), a small town located on Coliumo Bay, was one of the most devastated coastal areas and is currently under reconstruction. Therefore, the objective of this research is to analyze the risk factor...
Coastal floods have become a serious problem on a global scale (Yang et al., 2012). Exposure to this risk is high, mainly because a 50% of the global population is concentrated nin coastal areas, which are densely populated and economically attractive (Broekx et al., 2011; García & Loáiciga, 2014).
In the 20th century, the frequency of floods and t...
El humedal costero tipo marisma Tubul-Raqui, se localiza en el Golfo de Arauco (37°13’S-73°26’O), a 71 km al sur de Concepción, Región del Biobío. Formado en una gran llanura fluvial cuaternaria reciente, su pendiente débil y abierta hacia el NE produce que los principales ríos (Tubul y Raqui), presenten un marcado gradiente de salinidad (mixohalin...
A large earthquake and tsunami took place in February 2010, affecting a significant part of the Chilean coast (Maule earthquake (Mw = 8.8). Dichato (37° S), a small town located on Coliumo Bay, was one of the most devastated coastal places and is currently under reconstruction. Therefore, the risk factors which explain the disaster at that time as...
Se estudia el curso inferior del río Andalién situado en el Área Metropolitana de Concepción (AMC), segunda más poblada de Chile. Esta zona ha experimentado un 700% de crecimiento de la superficie urbana entre 1955-2007, con un registro de 21 eventos de inundaciones en los últimos 50 años. Se evalúa y zonifica áreas de peligrosidad de inundación fl...
The water footprint was calculated to evaluate the effects of climate variability on the water consumed during the production of cereals. This methodology considered three precipitation scenarios: a) rainy year, b) normal year and c) dry year. It also included two yield conditions -constant and a 20% reduction (projecting for the effect of climate...
Novoa, V., Rojas, O., Arumí, J. L., Ulloa, C., Urrutia, R., & Rudolph, A. (marzo-abril, 2016). Variabilidad de la huella hídrica del cultivo de cereales, río Cachapoal, Chile. Tecnología y Ciencias del Agua, 7(2), 35-50. Se evaluaron los efectos de la variabilidad climática en el consumo de agua para la producción agrícola de cereales, a través del...
Resumen Se analizaron los patrones espaciales del crecimiento urbano sobre las principales geo-formas costeras de la llanura de San Pedro de La Paz, ribera sur del río Biobío, durante el período 1955-2015. A través del uso de fotografías aéreas e imágenes satelitales recientes se identificaron estas geoformas costeras y se relacionaron con su conte...
RESUMEN La urbanización en Concepción metropolitano (36°S) en las últimas décadas ha impactado áreas de valor ecológico, tales como humedales y lagunas. Aquí anali-zamos la perturbación de parámetros de biodiversidad en seis humedales urbanos, mediante la exploración y uso de indicadores. Se proponen tres indicadores: na-turalidad y riqueza de macr...
Urbanization of the Metropolitan region of Concepción (36°S) in the last decades has impacted on the ecological value of areas such as wetlands and lagoons. Here, we analyse the disturbance to biodiversity indicators in six urban wetlands. Three measures are proposed: a naturalness indicator and two Macrolepidoptera plant indicators of species rich...
Urbanization in the Concepción metropolitan area (36° S) has historically impacted valuable ecological areas such as wetlands and lagoons. We built indicators to analyze disturbance of biodiversity in six urban wetlands. We propose three measures: a Naturalness indicator and two indicators for Plants and Macrolepidoptera species richness. Multiple...
El objetivo fundamental de esta investigación es Analizar, explicar y evaluar las relaciones entre cambios ambientales y dinámica de inundaciones fluviales en la sección inferior de la cuenca costera del río Andalién (36°S), Región del Biobío, Chile. Se indaga: tendencias históricas de las inundaciones, rol de la dinámica climática (variabilidad de...
Los tsunamis corresponden a uno de los desastres más devastadores; en horas o minutos pueden destruir amplios sectores. A los efectos inmediatos de un tsunami se agregan múltiples efectos socioambientales crónicos en comunidades pobres. El objetivo de este estudio fue evaluar los efectos socioambientales
del tsunami ocurrido el 27/02/2010 en Chile,...
Tsunamis correspond to one of the most devastating disasters. Within hours or minutes large sectors can be destroyed. To the immediate effects of a tsunami, multiple chronic effects to poor communities are added. The objective of the present study was to assess the social-environmental effects of the 02/27/2010 tsunami occurred in Chile, considerin...
A literature review of river floods from 1574 to 2012, allows us to analyze and identify the causes or trigger factors, recurrence periods, spatial distribution and geographical effects of flooding within continental Chile. Five types of flooding are identified, based on the triggering factor: volcanic processes, snow/glacial processes, landslides,...
Los tsunamis corresponden a uno de los desastres más devastadores; en horas o minutos pueden destruir amplios sectores. A los efectos inmediatos de un tsunami se agregan múltiples efectos socioambientales crónicos en comunidades pobres. El objetivo de este estudio fue evaluar los efectos socioambientales del tsunami ocurrido el 27/02/2010 en Chile,...
Tsunamis correspond to one of the most devastating disasters. Within hours or minutes broad sectors can be destroyed. However, to the immediate effects of a tsunami, multiple chronic effects to poor communities are added. The objective was to assess the social-environmental effects of the 27-F 2010 tsunami considering the socioeconomic vulnerabilit...
The risk of tsunami inundation is analyzed for an extreme event in the town of Tubul (37°S), Bio-Bio Region. Three scenarios were identified for risk assessment, in all of which numerical simulation was applied. Two of the three scenarios were local tsunamis, the events of 1835 and 2010, and the event of 1877 was included to determine the effects o...
The risk of tsunami inundation is analyzed for an extreme event in the town of Tubul (37°S), Bio-Bio Region. Three scenarios were identified for risk assessment, in all of which numerical simulation was applied. Two of the three scenarios were local tsunamis, the events of 1835 and 2010, and the event of 1877 was included to determine the effects o...
Uno de los principales sistemas fluviales de Chile central corresponde a la cuenca del río Maipo (15.380 Km2), que ha experimentado un rápido proceso de urbanización, debido a la expansión del área Metropolitana de Santiago. En su curso inferior, se ubica la comuna costera de Santo Domingo (33°56’ S - 71°33’ O), que registra un crecimiento inmobili...
La Región del Biobío presenta una importante recurrencia histórica de sismos tsunamigénicos que han generado graves efectos territoriales en la costa. El último terremoto Mw=8,8 del 27/F de 2010 y el posterior tsunami modificaron violentamente la geomorfología costera de la región, con efectos registrados a lo largo de 600 km, generándose a su vez...
The risk of tsunami inundation is analyzed for an extreme event in the town of Tubul (37°S), Bio-Bio Region. Three scenarios were identified for risk assessment, in all of which numerical simulation was applied. Two of the three scenarios were local tsunamis, the events of 1835 and 2010, and the event of 1877 was included to determine the effects o...
El 27 de febrero de 2010, la zona central de Chile fue afectada por uno de los eventos catastróficos más importantes del último tiempo, el terremoto Mw=8.8 y el posterior tsunami, que afectó una amplia zona. En la región del Biobío diversas ciudades y pueblos costeros fueron seriamente dañados, entre estos últimos Tubul-Raqui y Llico, localidades e...
Se presenta una revisión crítica respecto al estado del arte de los estudios de " Riesgos naturales". Se utilizan diversas fuentes para realizar un análisis fenomenológico de los principales conceptos relacionados. Los conceptos se complementan con ejemplos nacionales e internacionales. La revisión incluye la evolución del estudio de los riesgos, a...
El 27 de febrero de 2010 la costa de Chile central fue afectada por terremoto Mw=8.8 el cual generó un tsunami de magnitud 4 que asoló principalmente bahías pequeñas en un tramo costero de 800 km. Unas 484 personas perdieron la vida. En la Región del Bio-Bío, murieron 199 personas ya que en este sector se localiza la segunda conurbación más importa...
Se presentan los resultados del análisis de recurrencia histórica por inundación fluvial, realizado en el curso inferior de la cuenca costera del río Carampangue (37º06´7º41´S), localizada en la comuna de Arauco, Región del Bio-Bío, con el propósito de contribuir a la gestión del riesgo natural en la comuna. En este sector, se han registrado diecis...
Projects
Projects (6)
Evaluar escenarios de inundaciones fluviales bajo un contexto de cambio climático y cambios de uso de suelo en cuencas del centro-Sur de Chile al año 2050, con el objeto de proponer criterios para una planificación urbana sostenible que incorpore el enfoque de infraestructura verde.
Analyze how the expansion in cities of the metropolitan area of Concepción in different urban fabrics organized in typologies of neighborhoods, plus their respective accessibility, interact and affect the loss of surface area, perception of the provision of ecosystem services and flood mitigation in order to establish criteria for integrating the benefits of nature from these ecosystems, in favor of a sustainable and resilient urban development.
Research questions
What are the positive and negative impacts that resilience measures can have on vulnerable communities?
What are the key trade-offs to be made in order to increase resilience and render livelihoods more sustainable?
How effective are community-based soil-bioengineering techniques for reducing landslide risks?
Proyecto de Cooperación Universität St Gallen (Centro Latinoamericano-Suizo)-Universidad de Concepción (Centro en Ciencias Ambientales EULA-Chile) y Universidad de Los Andes (Colombia), 2017-2019.