Environmental and landscape rehabilitation plans : the case of Foz de Tua dam

The construction of Foz de Tua dam caused a severe environmental change at local level, producing a considerable visual impact that must be remedied and the disturbed area must be rehabilitated and recovered, approaching to the previous landscape before the dam construction. The affected area is close to the Alto Douro Vinhateiro World Heritage, what means special care is needed, considering at same time the humanized landscape and also the natural characteristics present in the area, namely for the vegetation. With this work, several interventions were proposed, aiming to reduce the visual impact caused namely by slope excavation, but also by vegetation removing, needed for the Foz Tua dam construction. For vegetation recovery, natural vegetation was identified and a recovery plan were developed, aiming to reproduce the previous landscape configuration by planting and seedling, considering both natural vegetation and cultivated areas structures. For exposed rocks we started some assays with the purpose of find a treatment for fresh cutted granite that could be used as a general rock treatment for visual impact of fresh excavated rocks. Some organic mixtures were tried, using also autochthonous lichens and moss, as well as chemical treatments, like acid or paint. Granite blocks were selected and five different treatments were applied to cover the fresh granitic blocks and trigger their colonization and aging. The experiment has been established on two groups of blocks, one submitted to irrigation three times a week and the other group does not. Each treatment had two repetitions per group. Two blocks for control were also established in each group to interpret the gaps of variation in comparison to the treated blocks. All the stone blocks were maintained in a greenhouse, with controlled temperature and humidity. The monitoring of the treatment was by taking pictures every 20 days, that were analyzed using RGB color characteristics and parameters that shows the evolution of pigmentation of the blocks. The results of this study show that three or at least two from the five experimented treatments are recommended to use in the disturbed area. The irrigation can be recommended also for the two to three first weeks after treatments establishment.A construção da barragem de Foz de Tua causou uma grave mudança ambiental a nível local, produzindo um impacto visual considerável que deve ser corrigida e a área perturbada deve ser reabilitada no sentido de repor, tanto quanto possível, da paisagem anterior à obra. A área afetada está próxima do Alto Douro Vinhateiro Património Mundial, o que exige um cuidado especial, considerando ao mesmo tempo a paisagem humanizada e também as características naturais presentes na área, nomeadamente para a vegetação. Com este trabalho, foram propostas várias intervenções, com o objetivo de reduzir o impacto visual causado, nomeadamente pela escavação das encostas, mas também pela remoção da vegetação, necessária à construção da barragem de Foz Tua. Para a recuperação da vegetação, foi preparado um plano de plantação, com o objetivo de reproduzir a configuração da paisagem anterior à construção, considerando também a estrutura da vegetação das áreas cultivadas. Para rochas expostas, iniciamos alguns ensaios com o propósito de encontrar um tratamento para granito cortado fresco com o intuito de reduzir o impacto visual da rocha recentemente cortada. Algumas misturas orgânicas foram testadas, usando líquenes e musgo autóctones, bem como tratamentos químicos, como ácido ou tinta. O ensaio foi estabelecido em blocos graníticos cortados frescos, mantendo-se dois grupos de blocos, um recebendo irrigação três vezes por semana e o outro grupo não. Cada tratamento teve uma repetição por grupo. Dois blocos de controle também foram estabelecidos em cada grupo para interpretar as lacunas de variação em comparação com os blocos tratados. Todos os blocos foram mantidos em estufa com temperatura e humidade controlados. Foi efetuada a recolha de fotos a cada 20 dias e analisada a evolução das intensidades e parâmetros de luz RGB dos blocks de rocha tratados e respetiva pigmentação. Os resultados mostraram que três dos tratamentos resultaram em alteração da cor da rocha, podendo ser recomendados para uso na área perturbada

Environmental and landscape rehabilitation: case study for fresh stone treatment on big dams

The construction of big dams usually cause a severe environmental change at a local level, producing a considerable visual impact that must be remedied and the disturbed area must be rehabilitated and recovered, approaching the landscape prior to the dam construction. In this work, several assays were tested, with the purpose of finding a treatment for fresh cut granite that could be used as a general rock treatment for visual impact of fresh excavated rocks. Some organic mixtures were tried, using autochthonous lichens and moss, as well as chemical treatments, like acid or paint. Granite blocks were selected and five different treatments were applied to cover the fresh granitic blocks and trigger their colonization and aging. The experiment has been established on two groups of blocks, one submitted to irrigation three times a week and the other without irrigation. Each treatment had two repetitions per group. Two blocks for control were also established in each group to interpret the gaps of variation in comparison to the treated blocks. All the stone blocks were maintained in a greenhouse, with controlled temperature and humidity. The monitoring of the treatment was done by taking pictures every 20 days, that were analyzed using RGB color characteristics and parameters that shows the evolution of pigmentation of the blocks. The results of this study show that three or at least two out of the five tested treatments are recommended to use in the disturbed areas. Irrigation can be more useful for the first two to three weeks after treatmentsinfo:eu-repo/semantics/submittedVersio