Dr. Pedro Alencar

Dr. Pedro Alencar

he/him

Brazilian hydrologist, scientist, and educator

Publications

You can also find my articles on my Google Scholar profile.

Journal Articles

Lessons learned in institutional preparedness and response during the 2022 European drought

Published in Natural Hazards and Earth System Sciences, 2026

This study quantifies the effectiveness of drought preparedness measures during the 2022 European drought using a survey of 481 respondents across 30 countries combined with hydroclimatic data (SPEI). Key findings reveal that organizations with forecasting systems implemented drought response measures two months earlier than those without, while those with Drought Management Plans (DMPs) responded one month earlier, with both groups rating their effectiveness higher. The research shows that 35% of respondents introduced or updated DMPs following the 2018 drought, demonstrating evolving awareness and preparedness. The study advocates for standardized, continent-wide drought risk management coordination and a European Drought Directive to integrate climatic and societal factors in addressing drought risk.

Recommended citation: Biella et al. (2026). "Lessons learned in institutional preparedness and response during the 2022 European drought." Nat. Haz. & Earth Sys. Sci.. 26(2):955–979. DOI: 10.5194/nhess-26-955-2026
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Sediment deposition patterns in reservoirs with different water-level dynamics relevant for potential sediment reuse

Published in Science of the Total Environment, 2025

This study analyzes sediment deposition patterns in eleven reservoirs across Brazi`s semiarid Jaguaribe Basin, revealing how water-level dynamics control granulometric segregation and nutrient distribution. Using correlation analysis, cluster analysis, and a novel Reservoir Emptying Index (REI), we demonstrate that reservoirs with high emptying frequency show greater sediment mixing, while low-frequency emptying reservoirs exhibit spatial segregation with sand near deltas and fine grains near dams. The findings provide a framework for predicting sediment characteristics and accessibility, supporting strategies for sediment removal and reuse in soil amendment, environmental rehabilitation, and construction materials.

Recommended citation: Lima et al. (2025). "Sediment deposition patterns in reservoirs with different water-level dynamics relevant for potential sediment reuse." Sci. Tot. Env.. 1009(1):181088. DOI: 10.1016/j.scitotenv.2025.181088
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The 2022 drought needs to be a turning point for European drought risk management

Published in Natural Hazards and Earth System Sciences, 2025

This study examines deficiencies in European drought risk management exposed by the 2022 European drought through a continent-wide survey of 481 water managers from 30 countries. The research reveals significant regional disparities in management capacity, with many agriculture-dominated countries employing short-term, reactive responses that can be maladaptive. While the 2022 drought affected most of Europe and highlighted growing drought risks due to increasing frequency and intensity, it also sparked increased organizational awareness and preparedness. The study advocates for a European Drought Directive to harmonize risk management policies and promote systemic, integrated, long-term approaches across the continent.

Recommended citation: Biella et al. (2025). "The 2022 drought needs to be a turning point for European drought risk management." Nat. Haz. & Earth Sys. Sci.. 25(11):4475-4501. DOI: 10.5194/nhess-25-4475-2025
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Brief communication: What do we need to know? Ten questions about climate and water challenges in Berlin-Brandenburg

Published in Natural Hazards and Earth System Sciences, 2025

This paper explores community-based approaches to co-creating water knowledge, highlighting participatory methods and the value of stakeholder engagement for sustainable water management.

Recommended citation: Alencar et al. (2025). "Brief communication: What do we need to know? Ten questions about climate and water challenges in Berlin-Brandenburg." Natural Hazards and Earth System Sciences. DOI: 10.5194/nhess-25-4043-2025
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Co-creating water knowledge: a community perspective

Published in Hydrological Sciences Journal, 2025

This paper explores community-based approaches to co-creating water knowledge, highlighting participatory methods and the value of stakeholder engagement for sustainable water management.

Recommended citation: Castelli et al., including Alencar (2025). "Co-creating water knowledge: a community perspective." Hydrological Sciences Journal. DOI: 10.1080/02626667.2025.2571065
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Exploring drought hazard, vulnerability, and related impacts on agriculture in Brandenburg

Published in Natural Hazards and Earth System Sciences, 2024

This study assesses drought hazard, vulnerability, and their impacts on agriculture in Brandenburg, providing insights for risk management and adaptation strategies in regional farming systems.

Recommended citation: Brill, Alencar, Zhang, Boeing, Hüttel, and Lakes (2024). "Exploring drought hazard, vulnerability, and related impacts on agriculture in Brandenburg." Natural Hazards and Earth System Sciences. 24(12):4237–4265. DOI: 10.5194/nhess-24-4237-2024
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Which droughts are becoming more frequent? A copula entropy analysis on the return period of droughts in Europe

Published in Natural Hazards, 2024

This study uses a copula entropy approach to analyze the return periods of droughts across Europe, identifying which types of droughts are becoming more frequent and highlighting regional variations in drought risk.

Recommended citation: Alencar and Paton (2024). "Which droughts are becoming more frequent? A copula entropy analysis on the return period of droughts in Europe." Natural Hazards. 121(1):543–565. DOI: 10.1007/s11069-024-06848-y
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Flash droughts and their impacts—using newspaper articles to assess the perceived consequences of rapidly emerging droughts

Published in Environmental Research Letters, 2024

This study analyzes newspaper articles to evaluate public perception of the impacts of rapidly emerging flash droughts, highlighting societal awareness and perceived consequences across different sectors.

Recommended citation: Alencar, Sodoge, Paton, and Madruga de Brito (2024). "Flash droughts and their impacts—using newspaper articles to assess the perceived consequences of rapidly emerging droughts." Environmental Research Letters. 19(7):074048. DOI: 10.1088/1748-9326/ad58fa
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Co-developing pathways to protect nature, land, territory, and well-being in Amazonia

Published in Nature Communications - Earth and Environment, 2023

Deforestation and climate change threaten social and ecological well-being in Amazonia. Research co-produced through ethical collaborations across multiple knowledge systems can contribute toward just and sustainable futures for the region.

Recommended citation: Nobrega, Alencar et al. (2023). "Co-developing pathways to protect nature, land, territory, and well-being in Amazonia." Nat Commun Earth Environ 4(364). DOI: 10.1038/s43247-023-01026-7
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Water Management causes increment of reservoir silting and reduction of water yield in the semiarid State of Ceará, Brazil

Published in Journal of South American Earth Sciences, 2023

This study shows how water management practices in Ceará, Brazil, increase reservoir siltation and reduce water yield, highlighting challenges for sustainable water resources in semiarid regions.

Recommended citation: de Araújo, Landwehr, Alencar, and Paulino (2023). "Water Management causes increment of reservoir silting and reduction of water yield in the semiarid State of Ceará, Brazil." Journal of South American Earth Sciences. 121:104102. DOI: 10.1016/j.jsames.2022.104102
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How do we identify flash droughts? A case study in Central European Croplands

Published in Hydrology Research, 2022

This study compares six flash drought identification methods at the station scale using data from four Central European cropland sites, evaluating their agreement through similarity and synchronicity metrics; the methods, based on soil moisture or climatic indices, are available in a public R package and Shiny app.

Recommended citation: Alencar and Paton (2022). "How do we identify flash droughts? A case study in Central European Croplands." Hydrology Research. 53(9). DOI: 10.2166/nh.2022.003
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Entropy-based Model for Gully Erosion – A combination of probabilistic and deterministic components

Published in Science of Total Environment, 2022

We present a gully erosion model based on net shear stress and a new hydraulic shear stress equation derived from the principle of minimum cross-entropy; with an efficiency of 0.77, it is suitable for catchments up to 8 ha and supports assessments of erosion, sediment yield, and gully geometry.

Recommended citation: Alencar et al. (2022). "Entropy-based Model for Gully Erosion – A combination of probabilistic and deterministic components." Science of Total Environment . 836. DOI: 10.1016/j.scitotenv.2022.155629
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Entropy-Based Temporal Downscaling of Precipitation as Tool for Sediment Delivery Ratio Assessment

Published in Entropy, 2021

This study presents an entropy-based method for temporal downscaling of precipitation, providing a tool to assess sediment delivery ratios and improve predictions of soil erosion processes.

Recommended citation: Alencar, Paton, and de Araújo (2021). "Entropy-Based Temporal Downscaling of Precipitation as Tool for Sediment Delivery Ratio Assessment." Entropy. 23(12):1615. DOI: 10.3390/e23121615
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Physically based model for gully simulation: application to the Brazilian semiarid region

Published in Hydrology and Earth Systems Sciences, 2020

To better understand soil loss in Brazil’s northeastern semiarid region, we developed a model—based on Foster and Lane (1983) and Sidorchuk (1999)—to simulate gully-erosion dynamics that threaten this desertification-prone area.

Recommended citation: Alencar et al. (2020). "Physically based model for gully simulation: application to the Brazilian semiarid region." HESS . 24(8). DOI: 10.5194/hess-24-4239-2020
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