Coastal erosion in 45 sandy beaches covering nearly 2000 km along the tectonically active Chilean coast is assessed during the last four decades. The historical analysis is based on the assessment of decadal changes of the shoreline position extracted from topographic surveys, aerial photographs, satellite images and survey maps using the DSAS software. Results show that 80% of the sites presented erosion rates (>−0.2 m/y), 7% beaches accreted (>0.2 m/y) while 13% remained stable. Eroded beaches include headland bay beaches, embayed and pocket beaches. A discussion on the possible causes explaining these results is conducted. While changes in offshore wave climate are spatially smooth within the region, relative mean sea level changes are highly variable and modulated by tectonic activity; the reduction of the sediment supply explains erosion rates in few cases.

La urbanización en Concepción metropolitano (36°S) en las últimas décadas ha impactado áreas de valor ecológico, tales como humedales y lagunas. Aquí analizamos la perturbación de parámetros de biodiversidad en seis humedales urbanos, mediante la exploración y uso de indicadores. Se proponen tres indicadores: naturalidad y riqueza de macrolepidópteros y plantas, los que se evalúan mediante modelos de regresión múltiple. Los resultados indican que los humedales con menor grado de perturbación antrópica se encuentran ubicados dentro de una reserva protegida y rodeados de una matriz de paisaje seminatural; mientras que los más perturbados están más próximos a la urbanización. Además, la riqueza de macrolepidópteros se ve más afectada por la distancia a carreteras, en cambio la riqueza de plantas por la densidad de viviendas. Se genera una herramienta para la evaluación de efectos de la urbanización en humedales urbanos.

<![CDATA[Se analiza el riesgo de inundación por tsunami para un evento extremo en la localidad de Tubul (37°S), Región del Biobío. Para el análisis de peligrosidad se determinaron tres escenarios asociados a los eventos tsunamigénicos locales de 1835 y 2010 a los cuales se aplicó modelamiento numérico. Se incluyó el evento de 1877 para determinar los efectos de un tsunami lejano. Se analizó la vulnerabilidad en sus dimensiones física, socioeconómica y educativa. El tsunami de 1835 se determinó como evento extremo, con alturas de inundación de 10 m y cota de inundación de 10 m. Se establecieron niveles de vulnerabilidad altos y medios explicados por la deficiente materialidad de la vivienda y perfil socioeconómico vulnerable de la población, bajos niveles de escolaridad y reacción frente a estos eventos. El riesgo natural obtenido se ubicó en niveles altos para toda la localidad. Se contrastan los resultados con el Plan de Reconstrucción vigente.]]>

Although Chile is one of the countries most exposed to natural hazards, to date there is no national index that shows the differences in resilience levels within the country. This study develops a community resilience index on a national scale based on the Baseline Resilience Community (BRIC) index. The BRIC index for Chile was built with 49 indicators, from different sources at the district level. Our results determined that resilience is not distributed homogeneously throughout the country. The highest levels of resilience are concentrated in the central macro-zone. In comparison, the extreme zones of Chile focus close to 90% of their population in the lowest levels, accounting for an uneven distribution of resources and services that impact resilience levels. These differences were mainly explained by indicators such as the percentage of the population without a health insurance system, the percentage of the population without internet access, and the percentage of electoral participation, among others. The results demonstrate that the BRIC model can be successfully implemented to assess community resilience in Chile and suggests the possibility of targeting resources and strategies to increase resilience in areas with the lowest levels of community resilience.

A large earthquake and tsunami took place in February 2010, affecting a significant part of the Chilean coast (Maule earthquake, M_w 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 factors that explain the disaster in 2010, as well as perceived restoration 6 years after the event. Numerical modeling of the 2010 Chile tsunami with four nested grids was applied to estimate the hazard. Physical, socioeconomic and educational dimensions of vulnerability were analyzed for pre- and post-disaster conditions. A perceived restoration study was performed to assess the effects of reconstruction on the community. It was focused on exploring the capacity of newly reconstructed neighborhoods to provide restorative experiences in case of disaster. The study was undertaken using the perceived restorativeness scale. The vulnerability variables that best explained the extent of the disaster were housing conditions, low household incomes and limited knowledge about tsunami events, which conditioned inadequate reactions to the emergency. These variables still constitute the same risks as a result of the reconstruction process, establishing that the occurrence of a similar event would result in a similar degree of devastation. For post-earthquake conditions, it was determined that all neighborhoods have the potential to be restorative environments soon after a tsunami. However, some neighborhoods are still located in areas devastated by the 2010 tsunami and again present high vulnerability to future tsunamis.