Effects of wildfires on water quantity and quality in southern Chile

Wildfires are a global and catastrophic phenomenon, generating major impacts on soil characteristics, erosion, water flow and water quality at the watershed scale, among others. Such effects depend on the severity of the fire, a metric that depends on the intensity of the fire and the nature of the vegetation that is burning. During the last 60 years the average annual area burned in Chile due to wildfires has been approximately 65,000 hectares per year. This figure has been greatly surpassed in the last 5 years, averaging approximately 155,000 hectares per year. Although worldwide, especially in the United States and Europe, there is evidence of impacts on the quantity and quality of water from wildfires, this is not the case in Chile. Given the above, the objective of this work is to analyze the effects on water quantity and quality in burned and unburned watersheds in the Andes and Coastal Cordillera in southern Chile. Two native forest basins and two exotic plantation basins were studied, one burned and one unburned in each class. The native forest basins correspond to the Allipén River and Quepe River basins, located in the Andes Mountain range, while the exotic plantation basins are found in the Carampangue River basin, located in the Coastal Mountain range. The results indicate differences in nutrients (phosphorus and nitrogen) present in the water between burned and unburned watersheds during the rainy season.