Panta Rhei benchmark dataset: socio-hydrological data of paired events of floods and droughts

As the adverse impacts of hydrological extremes increase in many regions of the world, a better understanding of the drivers of changes in risk and impacts is essential for effective flood and drought risk management and climate adaptation. However, there is currently a lack of comprehensive, empirical data about the processes, interactions and feedbacks in complex human-water systems leading to flood and drought impacts. Here we present a benchmark dataset containing socio-hydrological data of paired events, i.e., two floods or two droughts that occurred in the same area. The 45 paired events occurred in 42 different study areas and cover a wide range of socio-economic and hydro-climatic conditions. The dataset is unique in covering both floods and droughts, in the number of cases assessed, and in the quantity of socio-hydrological data. The benchmark dataset comprises: 1) detailed review style reports about the events and key processes between the two events of a pair; 2) the key data table containing variables that assess the indicators which characterise management shortcomings, hazard, exposure, vulnerability and impacts of all events; 3) a table of the indicators-of-change that indicate the differences between the first and second event of a pair. The advantages of the dataset are that it enables comparative analyses across all the paired events based on the indicators-of-change and allows for detailed context- and location-specific assessments based on the extensive data and reports of the individual study areas. The dataset can be used by the scientific community for exploratory data analyses e.g. focused on causal links between risk management, changes in hazard, exposure and vulnerability and flood or drought impacts. The data can also be used for the development, calibration and validation of socio-hydrological models. The dataset is available to the public through the GFZ Data Services (Kreibich et al. 2023, link for review: https://dataservices.gfz-potsdam.de/panmetaworks/review/923c14519deb04f83815ce108b48dd2581d57b90ce069bec9c948361028b8c85/).</p

Seguros hídricos como mecanismos de adaptação às mudanças do clima para otimizar a outorga de uso da água

Recent prolonged droughts make the urgent need to revise the criteria for water use permits in Brazil, especially in basins under conflicts for water use. Mechanisms for water risks transfer are an important adaptation tool. However, in Brazil, there is no established methodology that adapts this technique to assist the water use permit instrument. Moreover, there is no water risk insurance methodology with uncertainty analysis that complements its effectiveness in reducing losses from extreme events. Hydrologic modelling is the basis for development of these tools, which carries uncertainties that must be considered in decision-making. The objectives of this project were: i&#41; coupling climatic, hydrologic and water insurance models to evaluate the use permit decision-making; ii&#41; analyse sensitivity of performance indicators of a water risk insurance model through the application of different hydrologic models driven by climate change projections. The methodology was applied in donor basins of the Cantareira Water Supply System, which supplies water to an important metropolitan region that showed itself vulnerable to hydrologic extremes in the last years. The MHD-INPE and SWAT hydrologic models were applied, driven by the Eta- HadGEM2-ES climate model projections to characterize the future hydrologic regime in the region and also to compare the structure, performances and gaps of the models. Structural differences are most likely the greater responsible for the results differences, though no result could be identified as \"more certain\". With the hydrologic models outputs fitted the the Gumbel extreme values distribution, a proposed insurance fund simulator, MTRH-SHS, was run with 100 equiprobable scenarios of 50-year annual low-flow events to calculated an optimized premium capable of paying all indeminities of hydrologic drought. Besides the future hydrologic regimes, water demand scenarios were also tested. The optimized premiums were compared to the local GDP to assess the apparent affordability of the insurance, with some premium representing up to 0.54&#37; of local GDP, but in the water resources management framework, the decision should be made collectively by several actors within the basin&#39;s committee.Recentes estiagens fazem reconsiderar a necessidade de aperfeiçoar critérios de outorga de água no Brasil, especialmente em bacias com conflitos pelo uso da água. Seguros &#40;transferência de risco&#41; são importante ferramenta de adaptação. Contudo, no Brasil ainda não há metodologia consolidada que adapte esta técnica para auxiliar o instrumento de outorga de recursos hídricos. Ainda, não há metodologia de seguros hídricos com análise de incertezas, complementando sua efetividade ao reduzir os prejuízos advindos de eventos extremos. Modelos hidrológicos são a base de desenvolvimento destas ferramentas e carregam incertezas que devem ser integralizadas nos processos de decisão. Os objetivos deste projeto foram: i&#41; acoplar modelos: climático, hidrológico e de seguros hídricos para a avaliação do processo de decisão de outorga; ii&#41; realizar análise de sensibilidade dos indicadores de desempenho de modelo de seguros hídricos com diferentes modelos hidrológicos sob cenários de mudanças do clima. A metodologia foi aplicada nas bacias doadoras do Sistema Cantareira, que abastece importante região metropolitana e mostrou-se vulnerável a extremos hidrológicos nos últimos anos. Os modelos hidrológicos MHD-INPE e SWAT foram aplicados, forçados pelas projeções climáticas do modelo Eta-HadGEM2-ES a fim de caracterizar o regime hidrológico future na região, assim como comparar a estrutura, diferenças e performances dos modelos hidrológicos. As diferenças estruturais são provavelmente as maiores responsáveis pela diferença nos resultados, embora não seja possível apontar um modelo &#34;melhor&#34; que o outro. As saídas dos modelos foram ajustadas na distribuição de Gumbel e utilizada no modelo proposto de simulação de fundo de seguros, MTRH-SHS, rodado com 100 séries equiprováveis de 50 anos de eventos mínimos anuais. A cada série um prêmio otimizado é calculado para cobrir todas as indenizações de seca hidrológica. Além das projeções hidrológicas, cenários de demanda foram testados. Os prêmios otimizados foram comparados com o PIB local para demonstrar a viabilidade em implementar o seguro. Os valores representam até 0.54&#37; do PIB local em um dos casos, mas na gestão de recursos hídricos, a decisão final pela implementação deve ser feita no âmbito do comitê de bacias por múltiplos atores

Exploratory analyses for the assessment of climate change impacts on the energy production in an Amazon run-of-river hydropower plant

Study region: The Tapajós Basin is an important Amazon tributary affected by human activities with great potential for water conflicts. The basin, as others within the Amazon region, is receiving a number of hydropower plants, among them the Teles Pires plant, projected to operate in 2015. Study focus: Hydrological impacts due to climate change affect human activities, such as hydroelectric generation, and should be carefully studied for better planning of water management. In this study, we assess climate change impacts by applying the MHD-INPE hydrological model using several climate models projections as inputs. The impact assessment consisted of statistical shifts of precipitation and discharge. Energy production in a projected hydropower plant was assessed through the development of annual power duration curves for each projection, also considering its design and structural limitations. New hydrological insights for the region: The high inter-model variability in the climate projections drives a high variability in the projected hydrological impacts. Results indicate an increase of basin's sensitivity to climate change and vulnerability of water exploitation. Uncertainties prevent the identification of a singular optimal solution for impacts assessment. However, exploratory analysis of the plant design robustness for hydropower generation show a reduction in the energy production even under projections of increased discharge, due to plant capacity limitations. This is valuable information for stakeholders to decide about energy production strategies

Water quality and quantity primary data from field campaigns in the Cantareira Water Supply System, period Oct. 2013 - May 2014

Although hydrologic models provide hypothesis testing of complex dynamics occurring at catchments, freshwater quality modeling is still incipient at many subtropical headwaters. In Brazil, a few modeling studies assess freshwater nutrients, limiting policies on hydrologic ecosystem services. This paper aims to compare freshwater quality scenarios under different land-use and land-cover (LULC) change, one of them related to ecosystem-based adaptation (EbA), in Brazilian headwaters. Using the spatially semidistributed Soil and Water Assessment Tool (SWAT) model, nitrate, total phosphorous (TP) and sediment were modeled in catchments ranging from 7.2 to 1037 km². These headwaters were eligible areas of the Brazilian payment for ecosystem services (PES) projects in the Cantareira System, which had supplied water to 9 million people in the Sao Paulo metropolitan region. We considered SWAT modeling of three LULC scenarios: (i) recent past scenario (S1), with historical LULC in 1990; (ii) current land-use scenario (S2), with LULC for the period 2010-2015 with field validation; and (iii) future land-use scenario with PES (S2 + EbA). This latter scenario proposed forest cover restoration through EbA following the river basin plan by 2035. These three LULC scenarios were tested with a selected record of rainfall and evapotranspiration observed in 2006-2014, with the occurrence of extreme droughts. To assess hydrologic services, we proposed the hydrologic service index (HSI), as a new composite metric comparing water pollution levels (WPL) for reference catchments, related to the grey water footprint (greyWF) and water yield. On the one hand, water quality simulations allowed for the regionalization of greyWF at spatial scales under LULC scenarios. According to the critical threshold, HSI identified areas as less or more sustainable catchments. On the other hand, conservation practices simulated through the S2 + EbA scenario envisaged not only additional and viable best management practices (BMP), but also preventive decision-making at the headwaters of water supply systems

Trends and Climate Elasticity of Streamflow in South-Eastern Brazil Basins

Trends in streamflow, rainfall and potential evapotranspiration (PET) time series, from 1970 to 2017, were assessed for five important hydrological basins in Southeastern Brazil. The concept of elasticity was also used to assess the streamflow sensitivity to changes in climate variables, for annual data and 5-, 10- and 20-year moving averages. Significant negative trends in streamflow and rainfall and significant increasing trend in PET were detected. For annual analysis, elasticity revealed that 1% decrease in rainfall resulted in 1.21–2.19% decrease in streamflow, while 1% increase in PET induced different reductions percentages in streamflow, ranging from 2.45% to 9.67%. When both PET and rainfall were computed to calculate the elasticity, results were positive for some basins. Elasticity analysis considering 20-year moving averages revealed that impacts on the streamflow were cumulative: 1% decrease in rainfall resulted in 1.83–4.75% decrease in streamflow, while 1% increase in PET induced 3.47–28.3% decrease in streamflow. This different temporal response may be associated with the hydrological memory of the basins. Streamflow appears to be more sensitive in less rainy basins. This study provides useful information to support strategic government decisions, especially when the security of water resources and drought mitigation are considered in face of climate change

Trends and Climate Elasticity of Streamflow in South-Eastern Brazil Basins

Trends in streamflow, rainfall and potential evapotranspiration (PET) time series, from 1970 to 2017, were assessed for five important hydrological basins in Southeastern Brazil. The concept of elasticity was also used to assess the streamflow sensitivity to changes in climate variables, for annual data and 5-, 10- and 20-year moving averages. Significant negative trends in streamflow and rainfall and significant increasing trend in PET were detected. For annual analysis, elasticity revealed that 1% decrease in rainfall resulted in 1.21&ndash;2.19% decrease in streamflow, while 1% increase in PET induced different reductions percentages in streamflow, ranging from 2.45% to 9.67%. When both PET and rainfall were computed to calculate the elasticity, results were positive for some basins. Elasticity analysis considering 20-year moving averages revealed that impacts on the streamflow were cumulative: 1% decrease in rainfall resulted in 1.83&ndash;4.75% decrease in streamflow, while 1% increase in PET induced 3.47&ndash;28.3% decrease in streamflow. This different temporal response may be associated with the hydrological memory of the basins. Streamflow appears to be more sensitive in less rainy basins. This study provides useful information to support strategic government decisions, especially when the security of water resources and drought mitigation are considered in face of climate change

The challenge of unprecedented floods and droughts in risk management

International audienceAbstract Risk management has reduced vulnerability to floods and droughts globally 1,2 , yet their impacts are still increasing 3 . An improved understanding of the causes of changing impacts is therefore needed, but has been hampered by a lack of empirical data 4,5 . On the basis of a global dataset of 45 pairs of events that occurred within the same area, we show that risk management generally reduces the impacts of floods and droughts but faces difficulties in reducing the impacts of unprecedented events of a magnitude not previously experienced. If the second event was much more hazardous than the first, its impact was almost always higher. This is because management was not designed to deal with such extreme events: for example, they exceeded the design levels of levees and reservoirs. In two success stories, the impact of the second, more hazardous, event was lower, as a result of improved risk management governance and high investment in integrated management. The observed difficulty of managing unprecedented events is alarming, given that more extreme hydrological events are projected owing to climate change 3

Panta Rhei benchmark dataset: socio-hydrological data of paired events of floods and droughts

As the negative impacts of hydrological extremes increase in large parts of the world, a better understanding of the drivers of change in risk and impacts is essential for effective flood and drought risk management and climate adaptation. However, there is a lack of comprehensive, empirical data about the processes, interactions and feedbacks in complex human-water systems leading to flood and drought impacts. To fill this gap, we present an IAHS Panta Rhei benchmark dataset containing socio-hydrological data of paired events, i.e. two floods or two droughts that occurred in the same area (Kreibich et al. 2017, 2019). The contained 45 paired events occurred in 42 different study areas (in three study areas we have data on two paired events), which cover different socioeconomic and hydroclimatic contexts across all continents. The dataset is unique in covering floods and droughts, in the number of cases assessed and in the amount of qualitative and quantitative socio-hydrological data contained. References to the data sources are provided in 2022-002_Kreibich-et-al_Key_data_table.xlsx where possible. Based on templates, we collected detailed, review-style reports describing the event characteristics and processes in the case study areas, as well as various semi-quantitative data, categorised into management, hazard, exposure, vulnerability and impacts. Sources of the data were classified as follows: scientific study (peer-reviewed paper and PhD thesis), report (by governments, administrations, NGOs, research organisations, projects), own analysis by authors, based on a database (e.g. official statistics, monitoring data such as weather, discharge data, etc.), newspaper article, and expert judgement. The campaign to collect the information and data on paired events started at the EGU General Assembly in April 2019 in Vienna and was continued with talks promoting the paired event data collection at various conferences. Communication with the Panta Rhei community and other flood and drought experts identified through snowballing techniques was important. Thus, data on paired events were provided by professionals with excellent local knowledge of the events and risk management practices

Panta Rhei benchmark dataset: socio-hydrological data of paired events of floods and droughts (version 2)

As the negative impacts of hydrological extremes increase in large parts of the world, a better understanding of the drivers of change in risk and impacts is essential for effective flood and drought risk management and climate adaptation. However, there is a lack of comprehensive, empirical data about the processes, interactions and feedbacks in complex human-water systems leading to flood and drought impacts. To fill this gap, we present an IAHS Panta Rhei benchmark dataset containing socio-hydrological data of paired events, i.e. two floods or two droughts that occurred in the same area (Kreibich et al. 2017, 2019). The contained 45 paired events occurred in 42 different study areas (in three study areas we have data on two paired events), which cover different socioeconomic and hydroclimatic contexts across all continents. The dataset is unique in covering floods and droughts, in the number of cases assessed and in the amount of qualitative and quantitative socio-hydrological data contained. References to the data sources are provided in 2023-001_Kreibich-et-al_Key_data_table.xlsx where possible. Based on templates, we collected detailed, review-style reports describing the event characteristics and processes in the case study areas, as well as various semi-quantitative data, categorised into management, hazard, exposure, vulnerability and impacts. Sources of the data were classified as follows: scientific study (peer-reviewed paper and PhD thesis), report (by governments, administrations, NGOs, research organisations, projects), own analysis by authors, based on a database (e.g. official statistics, monitoring data such as weather, discharge data, etc.), newspaper article, and expert judgement. The campaign to collect the information and data on paired events started at the EGU General Assembly in April 2019 in Vienna and was continued with talks promoting the paired event data collection at various conferences. Communication with the Panta Rhei community and other flood and drought experts identified through snowballing techniques was important. Thus, data on paired events were provided by professionals with excellent local knowledge of the events and risk management practices