Lorenzo Alfieri

CIMA Research Foundation · Group of Hydrology and Hydraulics

Satellite Earth observations (EO) are an accurate and reliable data source for atmospheric and environmental science. Their increasing spatial and temporal resolution, as well as the seamless availability over ungauged regions, make them appealing for hydrological modeling. This work shows recent advances in the use of high-resolution satellite-bas...

INFORM Risk Index is a global indicator-based disaster risk assessment tool that combines hazards, exposure, vulnerability and lack of coping capacity indicators with the purpose to support humanitarian crisis management decisions considering the current climate and population. In this exploratory study, we extend the Index to include future climat...

Background Increasing human demand for water and changes in water availability due to climate change threatens water security worldwide. Additionally, exploitation of water resources induces stress on freshwater environments, leading to biodiversity loss and reduced ecosystem services. We aimed to conduct a spatially detailed assessment of global h...

The importance of studying and modeling river floods as global‐scale processes is becoming more and more evident. River floods are a major component of weather‐related hazards worldwide, and ongoing climate and socioeconomic change can further exacerbate impacts of floods in the future. Reducing flood impacts is now a priority of the global politic...

This poster session complements the related session on the Land stage, and through poster presentations and discussion will critically examine new and emerging approaches to adaptation.

River flooding in Europe could rise to unprecedented levels due to global warming and continued development in flood-prone areas. Here we appraise the potential of four key adaptation strategies to mitigate flood risk across Europe based on detailed flood risk modelling and cost-benefit analysis. We find that reducing flood peaks using retention ar...

River floods pose a significant threat to road transport infrastructure in Europe. This study presents a high-resolution object-based continental-scale assessment of direct flood risk of the European road network for the present climate, using high-resolution exposure data from OpenStreetMap. A new set of road-specific damage functions is developed...

Continental scale hazard maps for riverine floods have grown in importance in the last years. Nowadays, they are used for a variety of research and commercial activities, such as evaluating present and future risk scenarios and adaptation strategies, as well as a support of national and local flood risk management plans. Here, we present a new set...

The prolonged mei-yu/baiu system with anomalous precipitation in the year 2020 has swollen many rivers and lakes, caused flash flooding, urban flooding and landslides, and consistently wreaked havoc across large swathes of China, particularly in the Yangtze River basin. Significant precipitation and flooding anomalies have already been seen in magn...

Multi-hazard assessment is needed to understand compound risk. Yet, modelling of multiple climate hazards has been limitedly applied at the global scale to date. Here we provide a first comprehensive assessment of global population exposure to hydro-meteorological extremes -floods, drought and heatwaves- under different temperature increase targets...

Estimating how much water is flowing through rivers at the global scale is challenging due to a lack of observations in space and time. A way forward is to optimally combine the global network of earth system observations with advanced numerical weather prediction (NWP) models to generate consistent spatio-temporal maps of land, ocean, and atmosphe...

Abstract In spite of their recurrent seasonal patterns, every year river floods affect millions of people and kill thousands. Knowing the average timing and magnitude of floods can help to better prepare for disasters by improving the humanitarian assistance and the management of resources, to ultimately reduce the overall flood impacts. This work...

Continental-scale models of malaria climate suitability typically couple well-established temperature-response models with basic estimates of vector habitat availability using rainfall as a proxy. Here we show that across continental Africa, the estimated geographic range of climatic suitability for malaria transmission is more sensitive to the pre...

Global flood models integrate flood maps of constant probability in space, ignoring the correlation between sites and thus potentially misestimating the risk posed by extreme events. Stochastic flood models alleviate this issue through the simulation of flood events with a realistic spatial structure, yet their proliferation at large scales has his...

River flooding is the costliest natural disaster in Europe. Global warming and continued development in flood prone areas will progressively increase river flood risk. Direct damages from flooding could become six times present losses by the end of the century in case of no climate mitigation and adaptation. Keeping global warming well below 2°C wo...

The JRC PESETA IV study shows that ecosystems, people and economies in the EU will face major impacts from climate change if we do not urgently mitigate greenhouse gas emissions or adapt to climate change. The burden of climate change shows a clear north-south divide, with southern regions in Europe much more impacted, through the effects of extrem...

Abstract. River floods pose a significant threat to road transport infrastructure in Europe. This study presents a high-resolution object-based continental-scale assessment of direct flood risk of the European road network for the present climate, using high-resolution exposure data from OpenStreetMap. A new set of road-specific damage functions is...

Every year riverine flooding affects millions of people in developing countries, due to the large population exposure in the floodplains and the lack of adequate flood protection. Preparedness and monitoring are effective ways to reduce flood risk. State‐of‐the‐art technologies relying on satellite remote sensing as well as numerical hydrological a...

Flooding is the most damaging natural hazard, both economically and by population affected. Flood models are important tools for evaluating the risks associated with flooding. Historically, the modeling domain has been limited in scale; however, advancements in computing power and global data sets have led to the development of global flood models...

Hydrological models are usually calibrated against observed streamflow (Qobs), which is not applicable for ungauged river basins. A few studies have exploited remotely sensed evapotranspiration (ETRS) for model calibration but their effectiveness on streamflow simulation remains uncertain. This paper investigates the use of ETRS in the hydrological...

The outcomes of the 2015 Paris Agreement triggered a number of climate impact assessments, such as for floods and droughts, to focus on future time frames corresponding to the years of reaching specific levels of global warming. Yet, the links between the timing of the warming levels and the corresponding greenhouse gas concentration pathways to re...

The outcomes of the 2015 Paris Agreement triggered a number of climate impact assessments, such as for floods and droughts, to focus on future time frames corresponding to the years of reaching specific levels of global warming. Yet, the links between the timing of the warming levels and the corresponding greenhouse gas concentration pathways to re...

Abstract. Abstract. Estimating how much water is flowing through rivers at the global scale is challenging due to a lack of observations in space and time. A way forward is to optimally combine the global network of earth system observations with advanced numerical weather prediction (NWP) models to generate consistent spatio-temporal maps of land,...

Spatial and temporal variations of global floods during the TRMM period (1998-2013) are explored by means of the outputs of the Dominant river Routing Integrated with VIC Environment model (DRIVE) driven by the precipitation rates from the TRMM Multi-satellite Precipitation Analysis (TMPA). Climatological and seasonal mean features of floods includ...

Global and continental scale hydrological reanalysis datasets receive growing attention due to their increasing number of applications, ranging from water resources management, climate change studies, water related hazards and policy support. Until recently, their use was mostly limited to qualitative assessments, due to their coarse spatial and te...

Flooding is one of the main natural hazards in the world and causes huge economic and human impacts. Assessing the flood damage in the Mediterranean region is of great importance, especially because of its large vulnerability to climate change. Most past floods affecting the region were caused by intense precipitation events; thus the analysis of t...

The outcomes of the 2015 Paris Agreement triggered a number of climate impact assessments, such as for floods and droughts, to focus on future time frames corresponding to the years of reaching specific levels of global warming. Yet, the links between the timing of the warming levels and the corresponding greenhouse gas concentration pathways to re...

Improving flood modeling accuracy is crucial for real-time flood monitoring and early warning systems. Knowing the sources, patterns and driving factors of model uncertainty aids the development of more accurate flood predictions. This study investigates the consistency of two global flood inundation products, i.e., the Soil Moisture Active Passive...

The Greater Horn of Africa region increasingly experiences high risk of water scarcity. A combination of frequent droughts, rapid population growth and rising urbanization have reduced streamflow and intensified water abstraction, causing water and food shortages. Estimates of future streamflow changes in the region have so far been highly uncertai...

Flooding is one of the main natural hazard in the world and causes huge economic and human impacts. Assessing the flood damage in the Mediterranean region is of great importance, especially because its large vulnerability to climate change. Most past floods affecting the region were caused by intense precipitation events, thus the analysis of the l...

The economic impacts of disasters can reach far beyond the affected regions through interconnected transboundary trade flows. As quantification of these indirect impacts is complex, most disaster risk models focus on the direct impacts on assets and people in the impacted region. This study explicitly includes the indirect effects via regional econ...

For effective disaster risk management and adaptation planning, a good understanding of current and projected flood risk is required. Recent advances in quantifying flood risk at the regional and global scale have largely neglected critical infrastructure, or addressed this important sector with insufficient detail. Here, we present the first Europ...

Early warning systems (EWS) for river flooding are strategic tools for effective disaster risk management in many world regions. When driven by ensemble Numerical Weather Predictions (NWP), flood EWS can provide skillful streamflow forecasts beyond the monthly time scale in large river basins. Yet, effective flood detection is challenged by accurat...

Heat and cold waves may have considerable human and economic impacts in Europe. Recent events, like the heat waves observed in France in 2003 and Russia in 2010, illustrated the major consequences to be expected. Reliable Early Warning Systems for extreme temperatures would, therefore, be of high value for decision makers. However, they require a c...

The study assesses how climate change could affect Europe in eleven impact areas. Under a high warming scenario, several climate impacts show a clear geographical northsouth divide. Most of the welfare losses, assessed for six impact areas, would be greatly reduced under a 2ᵒC scenario. ► How to cite: ◄ Ciscar Martinez, J.-C., Ibarreta Ruiz, D.,...

In the version of this Letter originally published, the affiliation for Yukiko Hirabayashi was mistakenly given as ‘Institute of Industrial Science, The University of Tokyo, Bunkyō, Japan’. It should have read ‘Department of Civil Engineering, Shibaura Institute of Technology, Tokyo, Japan’. This has now been corrected.

This paper presents the calibration and evaluation of the Global Flood Awareness System (GloFAS), an operational system that produces ensemble streamflow forecasts and threshold exceedance probabilities for large rivers worldwide. The system generates daily streamflow forecasts using a coupled H-TESSEL land surface scheme and the LISFLOOD model for...

River floods are among some of the costliest natural disasters¹, but their socio-economic impacts under contrasting warming levels remain little explored². Here, using a multi-model framework, we estimate human losses, direct economic damage and subsequent indirect impacts (welfare losses) under a range of temperature (1.5 °C, 2 °C and 3 °C warming...

This is the first study to assess the possible changes in floods in the Bangladesh part of the densely populated Ganges–Brahmaputra–Meghna (GBM) delta at 1.5°C, 2°C, and 4°C global warming levels. This study was undertaken with the aim of joining the efforts of the global scientific community to assist in the preparation of the upcoming Special Rep...

We projected changes in weather extremes, hydrological impacts and vulnerability to food insecurity at global warming of 1.5°C and 2°C relative to pre-industrial, using a new global atmospheric general circulation model HadGEM3A-GA3.0 driven by patterns of sea-surface temperatures and sea ice from selected members of the 5th Coupled Model Intercomp...

Higher evaporative demands and more frequent and persistent dry spells associated with rising temperatures suggest that drought conditions could worsen in many regions of the world. In this study, we assess how drought conditions may develop across the globe for 1.5, 2, and 3°C warming compared to pre-industrial temperatures. Results show that 2/3...

Every year riverine flooding affects millions of people in developing countries, due to the large population exposure in the floodplains and the lack of adequate flood protection measures. Preparedness and monitoring are effective ways to reduce flood risk. State-of-the-art technologies relying on satellite remote sensing as well as numerical hydro...

Knowledge on the costs of natural disasters under climate change is key information for planning adaptation and mitigation strategies of future climate policies. Impact models for large scale flood risk assessment have made leaps forward in the past few years, thanks to the increased availability of high resolution climate projections and of inform...

This study investigates the change in the level of risk to critical infrastructure due to the impact of climate change on the frequency and severity of floods. We implement a case study focused on the power grid to demonstrate the methodology. The consideration of the power outage substantially changes the estimated losses from the flood scenario....

From 27 – 29 June 2017, the 2017 Global Flood Partnership Conference was held at the University of Alabama, U.S.A. More than 90 participants attended the conference coming from 11 different countries in 5 continents. They represented 56 institutions including international organisations, the private sector, national authorities, universities, gover...

The recently reached Paris Agreement at the 21st Conference of the Parties (COP21) of the United Nations Framework Convention on Climate Change (UNFCCC) in 2015 includes a goal of pursuing efforts to limit the global warming at 1.5 °C. Following this, the Intergovernmental Panel on Climate Change (IPCC) has accepted an invitation by the UNFCCC to c...

People, planet, prosperity and peace are four priorities shared by Africa and Europe, and areas where opportunities for beneficial cooperation abound. Over the past three decades, the European Commission’s Joint Research Centre (JRC) has worked with many organisations and institutions across Africa. This report and its accompanying interactive onli...

The development of methods for rapid flood mapping and risk assessment is a key step to increase the usefulness of flood early warning systems and is crucial for effective emergency response and flood impact mitigation. Currently, flood early warning systems rarely include real-time components to assess potential impacts generated by forecasted flo...

How do we manage water in cities? Where does our drinking water come from? Where does our waste water go? How much water do we consume? Is our life-style affecting our water? This first overview of Urban Water Management in Europe explains and illustrates water in an unprecedented way, reflecting how water flows through the arteries of our cities....

The release of high-resolution climatic projections through the Coordinated Regional Climate Downscaling Experiment (CORDEX) initiative provides unique opportunities to assess the risk of hydrological extremes in various world regions. The Brahmaputra is the second largest river in South Asia and is the main freshwater source of Bangladesh. Climate...

Rising global temperature has put increasing pressure on understanding the linkage between atmospheric warming and the occurrence of natural hazards. While the Paris Agreement has set the ambitious target to limiting global warming to 1.5°C compared to preindustrial levels, scientists are urged to explore scenarios for different warming thresholds...

Description: This collection contains a set of flood hazard maps, based on streamflow datafrom the European and Global Flood Awareness System (EFAS and GloFAS) and computed using two-dimensional hydrodynamic models. The European and global maps are documented in the following publications, repsectively: 1. Development and evaluation of a framework...

The development of methods for rapid flood mapping and risk assessment is a key step to increase the usefulness of flood early warning systems, and is crucial for effective emergency response and flood impact mitigation. Currently, flood early warning systems rarely include real–time components to assess potential impacts generated by forecasted fl...

Global warming is expected to considerably change the hydrological cycle, with higher temperatures resulting in higher potential evapotranspiration (PET), as well as in changes in the spatial and temporal distribution of precipitation, including more frequent and persistent dry periods. Therefore, coherent information on plausible future drought co...

Statistical approaches to study extreme events require, by definition, long time series of data. In many scientific disciplines, these series are often subject to variations at different temporal scales that affect the frequency and intensity of their extremes. Therefore, the assumption of stationarity is violated and alternative methods to convent...

While reported losses of climate-related hazards are at historically high levels, climate change is likely to enhance the risk posed by extreme weather events. Several regions are likely to be exposed to multiple climate hazards, yet their modeling in a joint scheme is still at the early stages. A multi-hazard framework to map exposure to multiple...

River floods generate a large share of the socio-economic impact of weather-driven hazards worldwide. Accurate assessment of their impact is a key priority for governments, international organization, reinsurance companies and emergency responders. Yet, available databases of flood losses over large domains are often affected by gaps and inconsiste...

Future flood risk in Europe is likely to increase due to a combination of climatic and socio-economic drivers. Effective adaptation strategies need to be implemented to limit the impact of river flooding on population and assets. This research builds upon a recently developed flood risk assessment framework at European scale to explore the benefits...

Nowadays, the development of high-resolution flood hazard models have become feasible at continental and global scale, and their application in developing countries and data-scarce regions can be extremely helpful to increase preparedness of population and reduce catastrophic impacts.The present work describes the development of a novel procedure f...

Statistical approaches to study extreme events require by definition long time series of data. The climate is subject to natural and anthropogenic variations at different temporal scales, leaving their footprint on the frequency and intensity of climatic and hydrological extremes, therefore assumption of stationarity is violated and alternative met...

The Global Flood Awareness System (GloFAS) is a pre-operational suite performing daily streamflow simulations to detect severe floods in large river basins. GloFAS defines the severity of a flood event with respect to thresholds estimated based on model simulated streamflow climatology. Hence, determining accurate and consistent critical thresholds...

River floods generate a large share of the socio-economic impact of weather-driven hazards worldwide. Accurate assessment of their impact is key priority for governments, international organizations, re-insurance companies and emergency responders. Yet, available databases of flood losses over large domains are often affected by gaps and inconsiste...

A large number of hydrological forecasting systems exist across the globe. Recent advances have pushed the limits of predictability of discharge and other hydrological variables from a few hours to several days or even months. In this chapter, we aim to give an overview of Hydrological Ensemble Prediction Systems across the globe. It provides brief...

At the current rate of global warming, the target of limiting it within 2 degrees by the end of the century seems more and more unrealistic. Policymakers, businesses and organizations leading international negotiations urge the scientific community to provide realistic and accurate assessments of the possible consequences of so called “high end” cl...