Soil erosion changes in Portugal between 1990 and 2018

Project Work presented as the partial requirement for obtaining a Master's degree in Geographic Information Systems and ScienceSoils provide important regulating ecosystem services and have crucial implications for human well-being and environmental conservation. However, soil degradation and particularly soil erosion jeopardize the maintenance and existence of these services. This study explores the spatio-temporal relationships of soil erosion to understand the distribution patterns of sediment retention services in mainland Portugal. Based on Corine Land Cover maps from 1990 to 2018, the InVEST Sediment Delivery Ratio (SDR) model was used to evaluate the influence of sediment dynamics for soil and water conservation. Spatial differences in the sediment retention levels were observed within the NUTS III boundaries, showing which areas are more vulnerable to soil erosion processes. Results indicated that the Region of Leiria, Douro and the coastal regions have decreased importantly sediment retention capacity over the years. However, in most of the territory (77.52%) changes in sediment retention were little or not important (i.e. less than 5%). The statistical validation of the model proved the consistency of the results, highlighting the usefulness of this methodology to analyse the state of soil erosion in the country. These findings can be relevant to support strategies for more efficient land use planning regarding soil erosion mitigation practices.Os solos fornecem serviços de ecossistemas reguladores e têm implicações cruciais para o bem-estar humano e conservação do ambiente. No entanto, a degradação dos solos, particularmente a erosão do solo, coloca em risco a manutenção e a existência destes serviços. Este estudo pretende analisar a distribuição espaciotemporal da erosão do solo, compreendendo os padrões espaciais da retenção de sedimentos em Portugal continental. Suportado pela utilização dos mapas Corine Land Cover de 1990 a 2018, o modelo Sediment Delivery Ratio (SDR) do InVEST foi utilizado para avaliar a influencia das dinâmicas dos sedimentos para a conservação dos solos e água. Variações espaciais dos níveis de retenção de sedimentos dentro dos limites dos NUTS III foram observados, mostrando quais as áreas mais suscetíveis aos processos de erosão do solo. Os resultados indicam ainda, que na Região de Leiria, Douro e nas regiões costeiras a capacidade de retenção de sedimentos decresceu significativamente no decorrer dos anos. No entanto, na maioria do território (77,52%) as mudanças em retenção de sedimentos foram pouco ou nada importantes (isto é, menos de 5%). A validação estatística do modelo comprova a consistência dos resultados, destacando a utilidade desta metodologia para a análise do estado da erosão do solo no país. Estas descobertas podem ser relevantes para apoiar estratégias para um ordenamento de território mais eficiente, relativamente às práticas de mitigação da erosão do solo

Characterisation of microbial attack on archaeological bone

As part of an EU funded project to investigate the factors influencing bone preservation in the archaeological record, more than 250 bones from 41 archaeological sites in five countries spanning four climatic regions were studied for diagenetic alteration. Sites were selected to cover a range of environmental conditions and archaeological contexts. Microscopic and physical (mercury intrusion porosimetry) analyses of these bones revealed that the majority (68%) had suffered microbial attack. Furthermore, significant differences were found between animal and human bone in both the state of preservation and the type of microbial attack present. These differences in preservation might result from differences in early taphonomy of the bones. © 2003 Elsevier Science Ltd. All rights reserved