| Name: | Description: | Size: | Format: | |
|---|---|---|---|---|
| 4.32 MB | Adobe PDF |
Authors
Advisor(s)
Abstract(s)
O presente trabalho pretendeu contribuir para a avaliação do status ecológico de sistemas lóticos situados no Nordeste Transmontano, mais propriamente na bacia hidrográfica do rio Sabor, afluente da margem direita do rio Douro. Para além da elevada variabilidade natural das condições edafo-climáticas nos sectores do Alto, Médio e Baixo Sabor, foram ainda tidos em conta diversos fenómenos de natureza antrópica que provocam, por norma, impactos negativos sobre os ecossistemas. De facto, a poluição doméstica e industrial, a extracção de inertes, os cortes exagerados da galeria ripícola, a agropecuária intensiva e a regularização de caudais são, de alguma forma, factores que podem ser presenciados na bacia do rio Sabor. Especial relevo assume o Aproveitamento Hidroeléctrico do Baixo Sabor (AHBS) que está actualmente em fase de construção e que, após o enchimento da barragem, será responsável pela criação dum novo espaço de características lênticas numa extensão aproximada de 50 Km, com o regolfo da albufeira situado na proximidade da confluência com o rio Maçãs. É nesta perspectiva que este estudo permitiu obter informação relevante para o futuro, uma vez que existem valores naturais ameaçados que importa preservar. Assim, durante o Outono de 2008, procedeu-se à avaliação das condições ecológicas de rios e ribeiras da bacia do Sabor, baseada na amostragem de parâmetros ambientais e de comunidades de macroinvertebrados. Seleccionaram-se 17 locais de amostragem distribuídos pelo rio principal e afluentes com diferentes tipologias e graus de perturbação. Foram usadas diferentes metodologias para determinar a qualidade da água e do habitat aquático, algumas delas recorrendo aos protocolos emanados da Directiva-Quadro da Água (DQA). A análise dos resultados obtidos permitiu diferenciar um padrão de variação longitudinal nas características abióticas e bióticas dos sistemas lóticos e identificar impactos de origem antrópica que originaram alterações substanciais na qualidade da água, morfometria do canal e zona ripária, assim como na composição faunística, diversidade, estrutura trófica e demais métricas avaliadas (e.g. índices IBMWP e IPtIN). Para além das principais conclusões inferidas no presente trabalho são ainda sugeridas algumas recomendações que se julgam poder ser relevantes para a salvaguarda destes ecossistemas e populações de invertebrados, algumas delas com estatuto de conservação.
This study sought to contribute to the assessment of ecological status of lotic systems located in the northeastern, more specifically in the river basin Sabor, a tributary of the right bank of the River Douro. In addition to the high natural variability of soil and climatic conditions in the areas of High, Middle and Lower Sabor were also taken into account various phenomena of nature and anthropogenic origins, which may produce negative impacts on aquatic ecosystems. In fact, the domestic and industrial pollution, the extraction of sediments, the degradation of riparian gallery, the intensive farming and regulation are, somehow, factors that can be witnessed in the Rio Sabor basin. Emphasis takes the Lower Hydroelectric Sabor (AHBS) that is currently under construction and, after filling the dam, will be responsible for creating a new area of lentic features with an extension of approximately 50 km, reaching to the confluence with the River Maçãs. This study allowed to obtain relevant information for the future, since there are threatened natural values that must be preserved. Thus, during the autumn of 2008, it was made the assessment of ecological conditions in rivers and streams in the Rio Sabor basin, based on sampling of environmental parameters and macroinvertebrate community. Seventeen sampling sites were selected and distributed across the main river and tributaries with different types and degrees of disturbance. We used different methodologies to determine water and aquatic habitat quality, some of them using the protocols issued by the Water Framework Directive (WFD). The results obtained allowed to differentiate a pattern of longitudinal variation in biotic and abiotic characteristics of lotic systems and identified impacts of anthropogenic origin, that led to substantial changes in water quality, channel morphology and riparian zone, as in the faunal composition, diversity, trophic structure and other metrics evaluated (e.g. indexes and IBMWP IPtIN). In addition to the main conclusions inferred in this work are also suggested some recommendations that can be relevant to the safeguarding of ecosystems and populations of invertebrates, some with conservation status.
This study sought to contribute to the assessment of ecological status of lotic systems located in the northeastern, more specifically in the river basin Sabor, a tributary of the right bank of the River Douro. In addition to the high natural variability of soil and climatic conditions in the areas of High, Middle and Lower Sabor were also taken into account various phenomena of nature and anthropogenic origins, which may produce negative impacts on aquatic ecosystems. In fact, the domestic and industrial pollution, the extraction of sediments, the degradation of riparian gallery, the intensive farming and regulation are, somehow, factors that can be witnessed in the Rio Sabor basin. Emphasis takes the Lower Hydroelectric Sabor (AHBS) that is currently under construction and, after filling the dam, will be responsible for creating a new area of lentic features with an extension of approximately 50 km, reaching to the confluence with the River Maçãs. This study allowed to obtain relevant information for the future, since there are threatened natural values that must be preserved. Thus, during the autumn of 2008, it was made the assessment of ecological conditions in rivers and streams in the Rio Sabor basin, based on sampling of environmental parameters and macroinvertebrate community. Seventeen sampling sites were selected and distributed across the main river and tributaries with different types and degrees of disturbance. We used different methodologies to determine water and aquatic habitat quality, some of them using the protocols issued by the Water Framework Directive (WFD). The results obtained allowed to differentiate a pattern of longitudinal variation in biotic and abiotic characteristics of lotic systems and identified impacts of anthropogenic origin, that led to substantial changes in water quality, channel morphology and riparian zone, as in the faunal composition, diversity, trophic structure and other metrics evaluated (e.g. indexes and IBMWP IPtIN). In addition to the main conclusions inferred in this work are also suggested some recommendations that can be relevant to the safeguarding of ecosystems and populations of invertebrates, some with conservation status.
Description
Keywords
Sistemas lóticos Macroinvertebrados Qualidade da água Habitat Biotipologia Influência antrópica
Citation
Silva, Liliana Andreia Ribalonga (2010). Avaliação da qualidade ecológica de sistemas lóticos da bacia hidrográfica do Rio Sabor (Bacia do Douro). Bragança : ESA. Dissertação de Mestrado em Gestão de Recursos Florestais
Publisher
Instituto Politécnico de Bragança, Escola Superior Agrária