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Percorrer UAlg-Teses por Objetivos de Desenvolvimento Sustentável (ODS) "ODS 13 — Ação Climática"
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- Ecohydrological assessment of a complex river-floodplain system for the enhancement of its multidimensional potentialPublication . Guzmán, Damaris Rios; Chicharo, Luis; Jarosiewicz, PawełRiver floodplain systems are critical for sustaining biodiversity and providing a wide range of ecosystem services. However, climate change and anthropogenic activities increasingly disrupt the hydrological and ecological connectivity of these systems, red ucing their resilience to external pressures. The degradation of floodplains undermines key ecosystem services, including the support of terrestrial and aquatic biodiversity, the regulation of hydrological extremes such as floods and droughts, and the sequ estration of carbon. Given the global challenges of water scarcity and associated ecological consequences, there is an urgent need for innovative management strategies to enhance the mult idimensional roles of floodplains in water resource management, biodiversity conservation, and climate change adaptation. Therefore, this thesis focused on the study of the river floodplain system that was selected as the demonstration site for the ecohydrological project LIFE Pilica (LIFE19 IPE/PL/000005) in Central Poland. The study addresse d the hydrological connectivity within the river floodplain system during spring and early summer, assessing its effects on water quality. A particular focus was placed on phosphorus dynamics between the water and sediment compartments, aiming to propose management strategies that mitigat e excessive phosphorus release for a sustainable water retention in the floodplain area. Three primary hydrological connection s were identified between the studied floodplain, Pilica river and an upstream wetland . The connectivity decreased significantly throughout the study (from 0.185 m 3 s 1 in March to 0.002 m 3 s 1 in May )), with the first connection turning into a drainage source in April due to Pilica’s water level decrease . By May, the second source dried up, and the third was projected to cease at a river discharge below 12 m³s⁻¹ (R² = 0.94). Principal Component Analysis (PCA) revealed a greater difference between water quality from the o xbow l ake with the river ’s inflow (35.4%) than with the wetland’s outflow ( 15.5%). This shift underscores an increased risk of eutrophication in both water bodies, driven by prolonged residence times, nutrient accumulation, and the lack of water exchange from the river. Sediment analysis revealed significant differences in water content and organic matter between samples ( p < 0.05 at the studied floodplain part . Most sediments were rich in organic phosphorus and bound to Fe, Al, and Mn. Sorption tests showed greater phosphorus adsorption in air dried sediments and a high zero equilibrium phosphorus concentration (EPC₀), indicating a tendency to release phosphoru s when exposed to river water , thus highlighting the need of proper management prior increasing hydrological connectivity . In conclusion, the implementation of a water retention basin in the area will tackle the greatest threat to the studied river floodplain system: the progressive loss of hydrological connectivity. Furthermore, the potential risk of phosphorus release was ev aluated to refine the management strategy , ensuring it effectively mitigates nutrient loading and supports long term ecosystem health.
- Ecohydrological nature-based solutions: assessment of sequential sedimentation-biofiltration system efficiency on the removal of nutrients from a polluted stream in central PolandPublication . Portillo, Olga Daniela Mejía; Chícharo, Luís; Jarosiewicz, PawełNutrient pollution in agricultural catchments is a major contributor to water quality degradation and ecosystem decline. Sequential Sedimentation-Biofiltration Systems (SSBS) represent an innovative Ecohydrological Nature-based Solution (EH-NbS) designed to mitigate nutrient and pollutant loads, thus improving surface water quality. The system is divided into three functional zones: sedimentation, biogeochemical, and biofiltration zones. However, the effectiveness of SSBS, as also other NbS designed to treat the water, is heavily reliant on proper maintenance and management. Therefore, understanding of the drivers behind the SSBS efficiency, including aging of the system and other abiotic processes, such as hydrology or temperature, may help to develop better, tailor-fitted solutions in future. This study assesses the performance of the SSBS system implemented in Przedbórz, Poland under ageing process (monitoring years compared between 2019 and 2022-2023 periods), seasonal variations and varying inflow discharge. The novelty of this study was that the water quality change was tested not only from the inlet and outlet, but also within each zone (sedimentation, geochemical, biofiltration) to quantify efficiency of different processes under external impacts. Focus was given to the nutrients pollution, however, since the phosphorus is more challenging in removal, to understand better the P dynamics in ageing system sediment samples from the sedimentation pond and stream were analyzed. Statistical analyses were performed to determine the significance of nutrient reduction over time. Results indicated that the SSBS system showed highest efficiency towards Total Suspended Solids (TSS) which were removed by 46.5% on average. Removal of Total Phosphorus (TP) and Total Nitrogen (TN), as also dissolved forms such as ammonium (N-NH₄) and nitrite (N-NO₂) were varying within the seasons but showed highest efficiency in summer with the following average levels, 21.4% for TP, 13.5% for TN, 31.1% for N-NH₄, and 16.2% for N-NO₂. Nevertheless, negative performance was observed also, especially during winter season as effectiveness in removal of TP (-78.9%), P-PO4 (-34.0%), TN (-40.2%) and dissolved N forms dropped substantially. Hydrology showed significant impact on the performance of TP and TN removal, specifically during warmer temperatures. Discharge, however, did not seem to have significant effect on the performance of this SSBS. Due to the lack of proper maintenance the sedimentation zone has clogged in October 2023. Therefore, this study focused on the characteristic of sediments in particular the phosphorus dynamics. Phosphorus fractionation in sediments revealed retention primarily in iron/manganese hydroxides and organic phosphorus (NaOH-NRP). Sediments were not significantly polluted by heavy metals, and the presence of TP as also high content of Organic Matter, suggest its reuse potential, that could help to facilitate the sediments removal process by the system owner. This study underscores the importance of regular maintenance and monitoring to ensure long-term SSBS performance and improvement of water resources quality.
- Nature-based solutions (NbS) for coastal ecosystem resilience enhancement: towards a conceptual model for marine pollution mitigationPublication . Boe, Gardawheh Gad; Sousa, Vânia Serrão; Ndah, AnthonyCoastal ecosystems, including mangroves, salt marshes, and coral reefs, perform various vital functions such as flood mitigation, erosion prevention, habitat conservation, and carbon sequestration. However, these ecosystems are encountering unparalleled challenges primarily due to climate change and anthropogenic activities that contribute to marine pollution, jeopardizing ecosystem integrity. The deterioration and destruction of coastal habitats undermine the natural resilience of these regions. Thus, the implementation of meticulously designed Nature-based Solutions (NbS) can facilitate the restoration and rehabilitation of compromised coastal ecosystems, mitigate marine pollution, and enhance economic and societal advantages in a cost-effective and sustainable manner. Examples encompass the rehabilitation of essential habitats, including seagrass and salt marshes, to safeguard biodiversity and facilitate carbon sequestration, as well as the management of coastal habitats to conserve biodiversity and shield populations from extreme weather phenomena. This master's thesis seeks to perform a thorough evaluation of the efficacy and potential of Nature-based Solutions (NbS), including habitat restoration, green infrastructure, and ecological engineering, in mitigating pollution effects and fostering long-term environmental sustainability, while also formulating a conceptual model for their effective application. The research will enhance the understanding of coastal resilience and offer pragmatic recommendations for coastal management and planning.
- Temporal variations in phenological patterns of olive ridley turtles (lepidochelys olivacea) in manono-bentiaba, AngolaPublication . Mangueira, Edson de Jesus Delgado; Baptista, Vânia; Gouvêa, Lidiane PiresSea turtles are migratory reptiles with a complex life cycle. Of the seven recorded species of sea turtles, three use Angolan waters: the leatherback, the green turtle and the olive ridley, which are confirmed as species that nest in Angola. Sea turtles play an important role in maintaining the balance of marine ecosystems, as they are marine and terrestrial bioindicators, participate in food chains and energy transfer, and have sociocultural and economic value. The decline in the sea turtle population is a cause for concern for their conservation, since all species are on the Angolan red list of species. Threats from climatic factors (temperature, precipitation, humidity, erosion, flooding, disease) and anthropogenic pressures (hunting and egg collection, coastal occupation and development, habitat degradation and high-powered vessels in sensitive areas) can influence the decline of these populations. In this context, the present study aims to examine the phenological patterns of Lepidochelys olivacea in Angola, with a specific focus on the Bentiaba region from 2018 to 2022. The surveys were conducted between September and March from 2018 to 2019 and from 2021 to 2022. The results showed a total of 264 nests during this period with declines in nesting and consequently in turtle hatching from 2018 to 2022, with 133 nests in the 2018-2019 season and 131 nests in the 2021-2022 season. October and December of 2018, February and March of 2019, presented with the highest egg density, while February and March of 2022, presented with the lowest egg density. November and December of 2021, and February and March of 2022, were the months with the highest mortality rate. This study includes monitoring nesting sites where eggs are laid and inspected, providing a baseline for conservation to identify the main stages where declines in nests, eggs and neonates occur.