Impact of wildfires on Portuguese closed waste dumps

• Autor(a) principal: Henriques, Patrícia Alexandra Machado
• Data de Publicação: 2020
• Tipo de documento: Dissertação
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10773/28914
• topic: Climate change; Contamination; Landfills; Municipal waste; Natural events; Waste dump; Wildfires

Portugal is a country extremely prone to forest fires, a combination of factors such as the Mediterranean climate, the lack of forest management and human ignition, combined with climate change, lead to the formation of small to catastrophic wildfires. Until the early 2000s, Portugal had 341 waste dumps scattered across the country, especially in forest areas, where waste was deposited without control, directly on the ground, using methods such as open combustion to reduce the volume of waste. This dissertation aimed to identify the impacts of wildfires in old closed waste dumps. For this purpose, two case studies of closed waste dumps affected by wildfires in 2017 (municipality of Nelas) and 2019 (municipality of A-a-Velha) were selected. However, only the case study of the closed waste dump affected by a wildfire in 2019 was a little more explored. The results of the field campaign revealed that the wildfire was of low severity, having not penetrated the deeper layers in the soil that reached the residues. However, the closed waste dump still contains organic residues that are combustible, and that can therefore represent a danger in an upcoming wildfire. The lower heating value of the waste from the waste dump was estimated at approximately 9.62 MJ/kg of waste (wet base). The stock of organic carbon present in these residues was estimated at between 4400 to 4900 ton, which, in case of complete combustion, would result in an emission of 16 to 18 thousand ton of CO2. From the literature overview carried out on the impacts of natural events in landfills and dumps (in operation and closed) it was found that the most portrayed events are coastal erosion, floods and fires (natural and anthropogenic). However, the number of studies reported is small, especially with regard to the impacts of wildfires in controlled landfills or dumps.