Three-dimensional modeling of wind- and temperature-induced flows in the Icó-Mandantes Bay, Itaparica Reservoir, NE Brazil

The Icó-Mandantes Bay is one of the major branches of the Itaparica Reservoir (Sub-Middle São Francisco River, Northeast Brazil) and is the focus of this study. Besides the harmful algae blooms (HAB) and a severe prolonged drought, the bay has a strategic importance—e.g., the eastern channel of the newly built water diversion will withdraw water from it (drinking water). This article presents the implementation of a three-dimensional (3D) numerical model—pioneering for the region—using TELEMAC-3D. The aim was to investigate the 3D flows induced by moderate or extreme winds as well as by heating of the water surface. The findings showed that a windstorm increased the flow velocities (at least one order of magnitude, i.e., up to 10−1–10−2 m/s) without altering significantly the circulation patterns; this occurred substantially for the heating scenario, which had, in contrast, a lower effect on velocities. In terms of the bay’s management, the main implications are: (1) the withdrawals for drinking water and irrigation agriculture should stop working during windstorms and at least three days afterwards; (2) a heating of the water surface would likely increase the risk of development of HAB in the shallow areas, so that further assessments with a water quality module are needed to support advanced remediation measures; (3) the 3D model proves to be a necessary tool to identify high risk contamination areas e.g., for installation of new aquaculture systems.DFG, 325093850, Open Access Publizieren 2017 - 2018 / Technische Universität Berli

Simulation of Wind-Induced Flow and Transport in a Brazilian Bay

Experimental and Computational Hydraulic

Simulations of nutrient emissions from a net cage aquaculture system in a Brazilian bay

Hydrodynamics and transport simulations were conducted with the modeling software TELEMAC-2D on Icó-Mandantes bay, a branch of the Itaparica reservoir. The bay has a maximal operational water level amplitude of 5 m and is suffering from eutrophication and algae bloom. Therefore, we investigated low and high water level scenarios with two different high resolution meshes, with the purpose to deeper understand their impact on transport of substances and to improve the watershed management. In particular, nutrient emissions from a hypothetical net cage aquaculture system located in the bay were investigated on half-year cycles. We observed a relevant impact on water quality for a tilapia production of 130 t y−1; i.e. after 6 months' simulation we obtained around 8 μgP L−1 and 6 μgP L−1 at the source of emissions, for low and high water scenarios, respectively

Simulation of Flow and Transport Processes in a Brazilian Reservoir

Experimental and Computational Hydraulic

How effectively (or not) can science and research be turned into adopted solutions and policies?

How to create an impact on policies, operations, and society across the interdisciplinary sectors in which we - as researchers - are involved? Managing the Water-Energy-Food-Ecosystem (WEFE) nexus and pursuing climate resilience is the core task of several European (EU) projects and is in the highest interests of our society. The European Commission’s research funding programs attempt to address a large range of topics and offer unique opportunities for scientists to create a tangible impact on the environment and society. We are currently involved in different EU projects, including AWESOME (PRIMA), which aims at managing the WEFE nexus across sectors and scales in the South Mediterranean exploring innovative technologies such as soilless agriculture in the Nile Delta; CLINT (H2020), which is developing Machine Learning (ML) techniques to improve climate science in the detection, causation, and attribution of extreme events to advance climate services; IMPETUS (H2020), whose efforts are dedicated on the elaboration of climate data space enhanced with ML algorithms to support the elaboration of climate policies; REACT4MED (PRIMA), which focuses on combating land degradation and desertification by improving sustainable land and water management through the identification of local good restoration practices and their potential upscaling; Gaza H2.0: Innovation and water efficiency (EuropeAid), which aims at promoting efficient and sustainable water supply and demand as well as knowledge transfer to enhance resilience against water scarcity in Gaza; GoNEXUS (H2020), which is developing an evaluation framework to design and assess innovative solutions for an efficient and sustainable coordinated governance of the WEFE nexus; NexusNet (COST), which creates the network and the community of WEF nexus advocates for a low-carbon economy in Europe and beyond; NEXOGENESIS (H2020), which focuses on streamlining water-related policies with artificial intelligence and reinforcement learning; MAGO (PRIMA), which builds web applications for water and agriculture in the Mediterranean; BIONEXT (HEU), which is interlinked with the Intergovernmental Panel on Biodiversity and Ecosystem Services and aims at creating transformative change through nexus analysis. Despite the efforts of the scientific community, there is still a gap between research and practice. Researchers face difficulties in engaging stakeholders and decision-makers to jointly explore and shape the developed solutions, as well as to truly adopt them. The large-scale implementation of suitable technological solutions might require time and financial resources beyond the project’s lifetime and capacity. The lack of follow-ups and collaboration among projects with similar aims can be some of the reasons lying behind. Also, the complexity of finding open data in data-scarce regions makes results less trustable in the eyes of international agencies, while the pressure of publishing often turns research tasks into pure academic exercises. To what extent does the European strategy work? Is it only gaining scientific advances or also leading to local policy changes? Engaging important local actors (e.g., ministries), small-medium enterprises and societal members in the project consortia, empowering scientists by ensuring feedback loops with local governmental agencies, including the human dimension into modelling, and running effective capacity-building campaigns can be some food for thoughts to shape new strategies

Modeling the impacts of climate extremes and multiple water uses to support water management in the Icó-Mandantes Bay, Northeast Brazil

The hydropower production, water supply and aquaculture services of the Itaparica Reservoir are of immense importance for the Brazilian Northeast. Uncontrolled water resources consumption (e.g. irrigation, water supply), climate and land use change effects deteriorated the water quantity and quality in the reservoir, leading to socio-economic and environmental problems. In this work, a depth-averaged shallow water model was set up for the Icó-Mandantes Bay, one major branch of the reservoir, using the open TELEMAC-MASCARET system. The aim was to assess the impacts of the newly built water diversion channel, as well as the effects of a flood and tracer transport from an intermittent tributary, both located in the bay. An alternative approach to estimate the water retention times was additionally implemented. The simulations showed that though the diversion channel did not significantly influence the hydrodynamics of the bay, it is necessary to continuously monitor water quality parameters in the withdrawal, especially during rainy periods after droughts, because of the nutrient inputs from the tributary and the overflows of the nearby drainage systems. Management measures adapting to the continuously changing natural conditions and anthropogenic impacts are thus indispensable and the model presented can be a valuable supporting tool for this purpose.BMBF, 01LL0904A, Verbundvorhaben INNOVATE: Nachhaltige Nutzung von Stauseen durch innovative Kopplung von aquatischen und terrestrischen Ökosystemfunktionen - Teilvorhaben 1: Verbundkoordination, Grüne Leber und Ökonomi

DIAGNÓSTICO DA QUALIDADE DA ÁGUA AO LONGO DE UM CANAL DE CONCRETO: UM ESTUDO DE CASO DO CANAL DO SERTÃO ALAGOANO - BRASIL

Para atender a demanda, a transferência de água de rios por canal é uma prática comum no Nordeste brasileiro. O Canal do Sertão Alagoano capta água do rio São Francisco (no reservatório Apolônio Sales) para abastecer municípios do estado de Alagoas. O objetivo deste trabalho foi analisar a evolução de parâmetros físico-químicos da água (temperatura, pH, turbidez, condutividade, dureza, sulfatos, cloretos, nitrogênio total e fósforo total) ao longo dos 29 km iniciais. Foram realizadas duas coletas no período seco em 10 pontos. Por meio do teste não-paramétrico MannWhitney, evidenciou-se que temporalmente as duas coletas são significativamente diferentes para todos os parâmetros, mesmo sendo ambas realizadas no período seco. Longitudinalmente, nas duas coletas, temperatura, pH e condutividade, foram significativamente diferentes entre o início e o final dos 29 km, apresentando uma tendência crescente nos valores. Quanto à qualidade, conforme a Resolução 357/2005 do CONAMA, a água do Canal apresentou valores dentro da Classe 1, com exceção do fósforo total