Evaluación de severidad de la quema para el incendio ocurrido en el Parque Nacional Torres del Paine a fines de la temporada 2011.
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Date
2015
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Universidad de Concepción
Abstract
El concepto de severidad de la quema surge a partir de la necesidad de identificar y cuantificar los efectos del fuego sobre el medioambiente, definida como el grado de cambio de un área quemada con respecto a las condiciones existentes antes del incendio, obteniéndose a partir de una evaluación en terreno que considera características visibles de la combustión. La severidad de la quema se ha transformado en un indicador cualitativo de los efectos del fuego sobre un ecosistema, permitiendo entre otras cosas observar respuestas del ecosistema, ante un incendio forestal, esto ha permitido apoyar una adecuada planificación y supervisión de actividades de recuperación ecológica, además de proporcionar información base para futuros monitoreos. En este contexto el Parque Nacional Torres del Paine ha sido afectado al menos en 29 oportunidades por incendios forestales durante el periodo comprendido entre los años 1985 y 2010, el último de ellos, ocurrido a fines del año 2011, es considerado uno de los más devastadores desde la creación del Parque, no solo por la superficie afectada, alrededor de 17.000 ha., sino por la severidad del incendio sobre la vegetación y los suelos. Debido a esto el Ministerio del Medioambiente ha planteado la necesidad de establecer un programa de restauración ecológica, incluyendo la rehabilitación y reparación de los ecosistemas afectados dentro del Parque, e incorporando una visión integrada y de largo plazo de los valores culturales y económicos del área como Reserva de la Biósfera. Aunque se han realizado estudios en el Parque que miden la severidad de la quema, estos no presentan mediciones en terreno de los efectos del fuego, y se basan principalmente en el uso de sensores remotos. El objetivo del presente estudio fue apoyar la realización de un plan de restauración ecológica en el Parque Nacional Torres del Paine, mediante la evaluación de la severidad de la quema a partir del incendio forestal ocurrido a fines de la temporada 2011. Se midieron los efectos visuales del fuego en terreno, lo que permitió calibrar y validar la información proveniente de sensores remotos, antes y después de ocurrido el incendio. Los resultados obtenidos indicaron que los índices espectrales dNBR y RdNBR se relacionaron de mejor manera con los valores de severidad obtenidos en el Parque Nacional. La segmentación de imágenes, como herramienta de trabajo, fue un buen aporte a la metodología de trabajo utilizada, ya que mejoró los resultados obtenidos por el clasificador, aumentando la fiabilidad global, la separabilidad entre clases de severidad de la quema y el índice kappa.
The concept of burn severity arises from the need to identify and quantify the effects of fire on the environment, defined as the degree of change of a burned regarding the conditions before the fire area, resulting from a field evaluation that considers visible combustion characteristics. Burn severity has been transformed into a qualitative indicator of the effects of fire on an ecosystem, allowing among other things ecosystem responses observed before a forest fire, this has allowed support proper planning and supervision of activities of ecological recovery, in addition to providing basic information for future monitoring. In this context the Torres del Paine National Park has been affected at least 29 times by forest fires during the period between 1985 and 2010, the last one, which occurred in late 2011, is considered one of the most devastating since the creation of the park, not only for the area affected, about 17,000 ha., but the severity of the fire on vegetation and soils. Because of this the Ministry of the Environment has raised the need for an ecological restoration program, including the rehabilitation and repair of affected ecosystems within the park, and incorporating an integrated, long-term economic vision and cultural values of the area as Biosphere Reserve. Although there have been studies in the park that measure the severity of the burn, they do not have field measurements of the effects of fire, and are primarily based on the use of remote sensors. The aim of this study was to support the implementation of a plan of ecological restoration in the Torres del Paine National Park, by assessing the severity of burning from forest fire occurred at the end of the 2011 season. Visual effects of fire on the ground were measured, enabling calibration and validation of information from remote sensors before and after the fire occurred. The results showed that the spectral indices were related DNBR and RdNBR better with severity values obtained in the National Park. Image segmentation, as a working tool, it was a good contribution to the work methodology used, as it improved the results obtained by the classifier, increasing overall reliability, separability between classes of burn severity and the kappa index.
The concept of burn severity arises from the need to identify and quantify the effects of fire on the environment, defined as the degree of change of a burned regarding the conditions before the fire area, resulting from a field evaluation that considers visible combustion characteristics. Burn severity has been transformed into a qualitative indicator of the effects of fire on an ecosystem, allowing among other things ecosystem responses observed before a forest fire, this has allowed support proper planning and supervision of activities of ecological recovery, in addition to providing basic information for future monitoring. In this context the Torres del Paine National Park has been affected at least 29 times by forest fires during the period between 1985 and 2010, the last one, which occurred in late 2011, is considered one of the most devastating since the creation of the park, not only for the area affected, about 17,000 ha., but the severity of the fire on vegetation and soils. Because of this the Ministry of the Environment has raised the need for an ecological restoration program, including the rehabilitation and repair of affected ecosystems within the park, and incorporating an integrated, long-term economic vision and cultural values of the area as Biosphere Reserve. Although there have been studies in the park that measure the severity of the burn, they do not have field measurements of the effects of fire, and are primarily based on the use of remote sensors. The aim of this study was to support the implementation of a plan of ecological restoration in the Torres del Paine National Park, by assessing the severity of burning from forest fire occurred at the end of the 2011 season. Visual effects of fire on the ground were measured, enabling calibration and validation of information from remote sensors before and after the fire occurred. The results showed that the spectral indices were related DNBR and RdNBR better with severity values obtained in the National Park. Image segmentation, as a working tool, it was a good contribution to the work methodology used, as it improved the results obtained by the classifier, increasing overall reliability, separability between classes of burn severity and the kappa index.
Description
Tesis presentada para optar al grado de Magister en Ciencias Forestales