Condiciones históricas de oleaje en el golfo de Arauco.
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Date
2025
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Publisher
Universidad de Concepción
Abstract
El aumento en la ocurrencia de las marejadas en los últimos años junto con el incremento en la demanda de infraestructura costera y el eventual aumento del nivel del mar debido al cambio climático aumentan el riesgo en la zona costera también afectada por terremotos y tsunamis. En el Golfo de Arauco, Biobío, Chile, la información pública sobre oleaje y sobre las marejadas es prácticamente nula. Para generar un sistema de alerta frente a marejadas es necesario determinar el clima de oleaje medio y extremo, para así identificar el oleaje que pueda afectar la actividad marítima y dañar la infraestructura de la costa. En este trabajo se evaluaron las condiciones históricas de oleaje en el Golfo de Arauco utilizando un modelo de oleaje retrospectivo debido a que las mediciones del oleaje existentes en el Golfo son insuficientes para realizar un análisis de largo plazo.
Se implementó el modelo espectral Wavewatch III para modelar el oleaje desde aguas profundas hasta las cercanías de la costa en la zona centro-sur de Chile. Se simularon 30 años de oleaje, desde enero del año 1994 hasta diciembre del año 2023, con el fin de generar información de largo plazo de la altura significativa, periodo peak, dirección media y peak del oleaje en el Golfo de Arauco. Los resultados del modelo son validados con series de tiempo de parámetros resumen del oleaje obtenidas costa afuera de Caleta Tumbes, Talcahuano, por la boya Watchkeeper perteneciente al SHOA. Luego se crearon mapas de parámetros resumen del oleaje promedio para la zona de estudio y se obtuvo el clima medio y extremo para diferentes puntos de interés dentro del Golfo de Arauco.
Se obtuvo un buen ajuste de la altura significativa con respecto a los datos observados. Se obtuvo un ajuste aceptable para el periodo peak y la dirección, pudiendo mejorarse si se agrega a la modelación información del viento local. Los mayores valores de altura significativa se observaron en Punta Lavapie y en la Isla Santa María. La altura del oleaje mínima se observa en Arauco (promedio 0.49 m). Para el clima extremo se destaca que las máximas alturas de oleaje se observaron en el nodo de Punta Lavapie, con valores superiores a los 5 m, el periodo de retorno a los 10 años varía entre 1.6 metros en Arauco y 4.7 metros en Punta Lavapie, para 100 años el mínimo está igualmente en Arauco con 1.8 m y el máximo en Punta Lavapie con 5.1 m.
The increase in the occurrence of storm surges in recent years together with the increase in demand for coastal infrastructure and the eventual rise in sea level due to climate change increase the risk in the coastal zone also affected by earthquakes and tsunamis. In the Gulf of Arauco, Biobío, Chile, public information on waves and swells is practically non-existent. In order to generate a large wave warning system, it is necessary to determine the average and extreme wave climate in order to identify the waves that can affect maritime activity and damage coastal infrastructure. In this work, the historical wave conditions in the Gulf de Arauco were evaluated using a retrospective swell model because the existing swell measurements in the Gulf are insufficient to perform a long-term analysis. The Wavewatch III spectral model was implemented to model the waves from deep water to near shore in south-central Chile. Thirty years of waves were simulated, from January 1994 to December 2023, in order to generate long-term information of the significant height, peak period, mean direction and peak of the waves in the Gulf of Arauco. The model results are validated with time series of wave summary parameters obtained offshore of Caleta Tumbes, Talcahuano, by the Watchkeeper buoy belonging to SHOA. Then, maps of average wave summary parameters were created for the study area and the mean and extreme climate were obtained for different points of interest within the Gulf of Arauco. A good fit of the significant height to the observed data was obtained. An acceptable fit was obtained for peak period and direction, which could be improved by adding local wind information to the modeling. The highest significant height values were observed at Punta Lavapie and Santa Maria Island. The minimum wave height was observed in Arauco (average 0.49 m). For the extreme climate, the maximum wave heights were observed at the Punta Lavapie node, with values greater than 5 m, the 10-year return period varies between 1.6 m at Arauco and 4.7 m at Punta Lavapie, and for 100 years the minimum is also at Arauco with 1.8 m and the maximum at Punta Lavapie with 5.1 m.
The increase in the occurrence of storm surges in recent years together with the increase in demand for coastal infrastructure and the eventual rise in sea level due to climate change increase the risk in the coastal zone also affected by earthquakes and tsunamis. In the Gulf of Arauco, Biobío, Chile, public information on waves and swells is practically non-existent. In order to generate a large wave warning system, it is necessary to determine the average and extreme wave climate in order to identify the waves that can affect maritime activity and damage coastal infrastructure. In this work, the historical wave conditions in the Gulf de Arauco were evaluated using a retrospective swell model because the existing swell measurements in the Gulf are insufficient to perform a long-term analysis. The Wavewatch III spectral model was implemented to model the waves from deep water to near shore in south-central Chile. Thirty years of waves were simulated, from January 1994 to December 2023, in order to generate long-term information of the significant height, peak period, mean direction and peak of the waves in the Gulf of Arauco. The model results are validated with time series of wave summary parameters obtained offshore of Caleta Tumbes, Talcahuano, by the Watchkeeper buoy belonging to SHOA. Then, maps of average wave summary parameters were created for the study area and the mean and extreme climate were obtained for different points of interest within the Gulf of Arauco. A good fit of the significant height to the observed data was obtained. An acceptable fit was obtained for peak period and direction, which could be improved by adding local wind information to the modeling. The highest significant height values were observed at Punta Lavapie and Santa Maria Island. The minimum wave height was observed in Arauco (average 0.49 m). For the extreme climate, the maximum wave heights were observed at the Punta Lavapie node, with values greater than 5 m, the 10-year return period varies between 1.6 m at Arauco and 4.7 m at Punta Lavapie, and for 100 years the minimum is also at Arauco with 1.8 m and the maximum at Punta Lavapie with 5.1 m.
Description
Tesis presentada para optar al título de Ingeniero/a Civil.
Keywords
Contorno del litoral, Golfos, Olas