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The quest for hydrological hyper-resolution modelling has been on-going for more than a decade. While global hydrological models (GHMs) have seen a reduction in grid size, they have thus far never been consistently applied at a hyper-resolution (<=1 km) at the large scale. Here, we present the first application of the GHM PCR-GLOBWB at 1 km over Europe. We thoroughly evaluated simulated discharge, evaporation, soil moisture, and terrestrial water storage anomalies against long-term observations and subsequently compared results with the established 10 and 50 km resolutions of PCR-GLOBWB. Subsequently, we could assess the added value of this first hyper-resolution version of PCR-GLOBWB and assess the scale dependencies of model and forcing resolution. Eventually, these insights can help us in understanding the current challenges and opportunities from hyper-resolution models and in formulating the model and data requirements for future improvements. We found that, for most variables, epistemic uncertainty is still large, and issues with scale commensurability exist with respect to the long-term yet coarse observations used. Merely for simulated discharge, we can confidently state that model output at hyper-resolution improves over coarser resolutions due to better representation of the river network at 1 km. However, currently available observations are not yet widely available at hyper-resolution or lack a sufficiently long time series, which makes it difficult to assess the performance of the model for other variables at hyper-resolution. Here, additional model validation efforts are needed. On the model side, hyper-resolution applications require careful revisiting of model parameterization and possibly the implementation of more physical processes to be able to resemble the dynamics and spatial heterogeneity at 1 km. With this first application of PCR-GLOBWB at 1 km, we contribute to meeting the grand challenge of hyper-resolution modelling. Even though the model was only assessed at the continental scale, valuable insights could be gained which have global validity. As such, it should be seen as a modest milestone on a longer journey towards locally relevant model output. This, however, requires a community effort from domain experts, model developers, research software engineers, and data providers.

Climate change linked to human activities is affecting natural systems, increasing frequency and severity of water-related hazards. The issue of climate change pushes to tackle the expected risks in the water sector through a comprehensive and global view, with a revision of the paradigms considered as drivers of water resources development. Based on the evolution of these paradigms in Italy the main characteristics of an adaptive approach to climate change and other global changes are discussed relatively to water infrastructures, legislative and institutional frameworks. The objective of adaptation strategies is the increase of resilience of water systems, emphasizing the capability of reducing both physical and socio-political vulnerability, improving the governance of water services. Starting from the analysis of the evolution of water management, priorities for coping with future challenges are discussed with reference to the reduction of the risk of water shortage due to drought, to the mitigation of flood risk, and to the issues concerning the water-food-energy nexus.

The mass movement towards stream beds and their accumulation there may cause flood events as a result of landslide events. In this study, Devrek Landslide, which occurred in 2015, was investigated by using a remote sensing technique. The Çomaklar stream is located at the lower elevations of this landslide region. Çomaklar stream and surrounding settlements are at risk of flooding due to the probability of preventing the water flow in the stream because of the effects of the landslide. Devrek district is located in Zonguldak in the northern part of Turkey. LANDSAT-8 satellite images between the dates 27 January 2015 and 22 July 2015 were used to investigate the location and size of the Devrek district landslide. Satellite-derived remote sensing data have been widely used in recent years to monitor changes on the earth's surface and to provide information. In this study, the Spectral Angle Difference method was used to compare the images before and after the landslide event. A change detection analysis was conducted between pre-landslide and post-landslide images to investigate the area affected by the disaster. As a result, the landslide was determined as 1050 meters in length and 110 meters in width, and the landslide area was calculated as 10.87 ha., Heyelan olayları sonucunda akarsu yataklarına doğru kütle hareketi olması ve orada yığılması taşkın olaylarına neden olabilmektedir. Bu çalışmada 2015 yılında meydana gelen Devrek Heyelanı uzaktan algılama tekniği kullanılarak incelenmiştir. Çomaklar deresi bu heyelan bölgesinin alt kotlarında yer almaktadır. Çomaklar deresi ve çevresindeki yerleşimler, heyelan ile hareket eden kütlenin dereyi kapatması ihtimali ve etkilerinden dolayı, taşkın riski altındadır. Devrek ilçesi, Türkiye'nin kuzey kesiminde Zonguldak'ta yer almaktadır. Devrek ilçesi heyelanın yerini ve boyutunu araştırmak için 27 Ocak 2015 ve 22 Temmuz 2015 tarihleri arasında LANDSAT-8 uydu görüntüleri kullanılmıştır. Uydu kaynaklı uzaktan algılama verisi, yeryüzü üzerindeki değişimleri izlemek ve bilgi temin etmek için son yıllarda yaygın olarak kullanılmaktadır. Bu çalışmada heyelan olayı öncesi ve sonrası görüntülerin karşılaştırılmasında Spektral Açı Farkı yöntemi kullanılmıştır. Afetten etkilenen alanı araştırmak için heyelan öncesi ve heyelan sonrası görüntüler arasında değişim tespit analizi yapılmıştır. Sonuç olarak heyelan uzunluğu 1050 metre, genişliği 110 metre, heyelan alanı ise 10.87 ha olarak hesaplanmıştır.

Si la littérature a pu montrer les inégalités socio-économiques d’exposition des populations face aux effets du changement climatique, il reste un champ de recherche en sciences sociales à combler sur l’analyse des effets distributifs socio-spatiaux des politiques d’adaptation au changement climatique. Dans ce contexte, cet article questionne les politiques de gestion du risque d’inondation en France et les effets procéduraux et redistributifs de ces dernières. En se fondant sur le cadre théorique de la justice environnementale, l’article interroge les dispositifs mis en œuvre depuis le début des années 2000 dans le projet de réaménagement du quartier inondable de la Bouillie, à Blois. Marqué par une lourde opération de désurbanisation et désormais un réinvestissement des collectivités locales, ce projet est accompagné d’une politique participative qui vise à définir de nouveaux usages partagés et fonctions réversibles, basés sur un tissu associatif dense et des formes de « solidarité réflexive » autour de la durabilité et de l’inclusion. Pour autant, certains usages ou fonctions du site sont évincés (tels que la présence de Voyageurs) et sont vus comme « peu compatibles » avec les futurs en construction du site. Les mécanismes de solidarité publicisés dans la politique de réaménagement peuvent induire une légitimation sélective de certains usages du territoire et mener à la mise en place de régimes d’exclusion. Although literature has already demonstrated socio-economic inequalities in face of climate change, there is still a knowledge gap in social sciences about the socio-spatial effects of climate change adaptation policies. In this context, this article questions flood risk management policies in France and investigates their procedural and distributive effects. Using the theoretical framework of environmental justice, we examine the mechanisms implemented since the early 2000s in the redevelopment project of the flood-prone area of La Bouillie in Blois. Marked by a heavy de-urbanization operation and now a reinvestment of local authorities, this project is accompanied by participatory mechanisms that aim at defining new shared uses and reversible functions, based on a dense associative network and forms of "reflexive solidarity" around sustainability and inclusion. However, some uses or functions of the site barely taken into account (such as the presence of travelers) and are seen as "not compatible" with the future of the site. In this paper, we show that the solidarity mechanisms publicized in the redevelopment policy may also induce a selective legitimization of certain uses of the area and lead to the establishment of exclusionary regimes.

The main natural risk in the Mediterranean region is flooding. Therefore, in Spain, explaining this issue in Primary Education classrooms of Social Sciences should be a priority and is established as such in the current curriculum. The aims of this study are to carry out an analysis of the contents on flood risk included in the Social Science textbooks (3rd cycle; 5th and 6th) of Primary Education of the leading publishers used in Spain (Anaya, Bromera, Santillana, SM and Vicens Vives), in terms of: (1) the meaning of this phenomenon; (2) the causes and consequences of floods; and (3) an analysis of the images (catastrophism and territory location) that are included in the textbooks to explain these events. The results indicate that there is no complete definition of flood risk provided in these textbooks; the information is mainly related to the physical factor (atmospheric event). There is no specific mention of how human beings affect risk (vulnerability and exposure factor). With respect to the causes of floods, the analysis finds confusion in the explanations from the different textbooks and publishers, and the images that are included are sensationalist, highlighting the catastrophism without indicating to which territory it refers.

Flood risk assessment is an important tool for urban planning, land development, and hydrological analysis. The flood risks are very high in arid countries due to the nature of the rainfall resulting from thunderstorms and the land cover, which comprises mostly very dry arid soil. Several methods have been used to assess the flood risk, depending on various factors that affect the likelihood of occurrence. However, the selection of these factors and the weight assigned to them remain rather arbitrary. This study assesses the risk of flood occurrence in arid regions based on land cover, soil type, precipitation, elevation, and flow accumulation. Thematic maps of the aforementioned factors for the study area were prepared using GIS. The Fuzzy Analytic Hierarchy Process (F-AHP) was used to calculate the likelihood of the flood occurrence, and land use was used to assess the exposure impact. Using the likelihood map (i.e., probability) from the Fuzzy-AHP and an exposure map, the flood risk was assessed. This method was applied to Qatar as a case study. Results were compared with those produced by fuzzy logic. To explore the pairwise importance of the F-AHP, equal weight analysis was performed. The resulting risk map shows that the majority of urbanized areas in Qatar are within the high-risk zone, with some smaller parts within the very high flood-risk area. The majority of the country is within the low-risk zone. Some areas, especially land depressions, are located within the intermediate-risk category. Comparison of Fuzzy logic and the F-AHP showed that both have similarities in the low-risk and differences in the high-risk zones. This reveals that the F-AHP is probably more accurate than other methods as it accounts for higher variability.

The dynamically changing world poses new challenges to urbanized areas, e.g., related to water management in the architectural and urban context. Improving retention and strengthening blue-green infrastructure can be based on technical, semi-natural and natural methods, which are less invasive. Various forms are used in the city space: flow control, detention, retention, filtration, infiltration, and treatment. The implementation of the green order strategy and shaping sustainable development in the context of designing the city’s resilience is associated with shaping spatial policy and urban planning assumptions for the transformation of public spaces and new investments in urbanized areas in crisis. The shaping of waterfronts in the city and green and blue infrastructure significantly shape the parameters of the environment and the regenerative capacity of the urban ecosystem. The aim of this work was to show the relationship between the problem of embankments and the possibilities of developing space in their proximity, including areas exposed to the risk of flooding. The relationships determined by the goal were verified in comparative studies, a repeatable method of collecting, processing, analyzing, and interpreting the obtained data was used. The issue was presented in a broader context of flood risk and water management in the area of Lake Zegrze, collisions and spatial conflicts were analyzed. The results are presented in the context of detailed water management data for the complex of Riva Zegrze facilities, which is a model example regarding the sustainable development of areas on embankments, considering their specific floodplain development possibilities. The effects of the research allowed for the formulation of conclusions, including in terms of implementation, in the field of urban and architectural design for areas associated with an embankment.

Flood risk has increased distressingly, and the incidence of waterborne diseases, such as diarrhoeal diseases from bacteria, has been reported to be high in flood-prone areas. This study aimed to evaluate the flood risk patterns and the plausible application of flow cytometry (FCM) as a method of assessment to understand the relationship between flooding and waterborne diseases in Malaysia. Thirty years of secondary hydrological data were analysed using chemometrics to determine the flood risk patterns. Water samples collected at Kuantan River were analysed using FCM for bacterial detection and live/dead discrimination. The water level variable had the strongest factor loading (0.98) and was selected for the Flood Risk Index (FRI) model, which revealed that 29.23% of the plotted data were high-risk, and 70.77% were moderate-risk. The viability pattern of live bacterial cells was more prominent during the monsoon season compared to the non-monsoon season. The live bacterial population concentration was significantly higher in the midstream (p < 0.05) during the monsoon season (p < 0.01). The flood risk patterns were successfully established based on the water level control limit. The viability of waterborne bacteria associated with the monsoon season was precisely determined using FCM. Effective flood risk management is mandatory to prevent outbreaks of waterborne diseases.

A flood can be a severe event, causing not only material damage but also immaterial, such as stress and discomfort. Yet, the risk of flooding may not always be known to house buyers before purchase. In this paper, we estimate the immaterial cost of flood risk from coastal flooding using the hedonic house price approach. The analysis is based on a rich house price dataset that identifies flooded houses using insurance data. The design of the insurance mechanism makes it possible to separate material and immaterial damage as all houses are insured independently of the flood risk. Applying a difference-in-differences design, we study the effect of changes in flood risk information, namely the publication of flood maps, and a flood event in Denmark in 2013. By estimating a time-variant house price function, we can infer the welfare implications of non-marginal changes in flood-risk perception. We find that households have a maximum WTP of 21% of the house price to avoid being flooded after a flood event and that this effect diminishes over time. Houses located in a flood risk zone are sold with an 8.4% price discount but controlling for inundation removes the impact of the flood map.

Ilustraciones La respuesta hidrológica (HR) de los cauces a eventos de precipitación, es reportada como un proceso de importante variabilidad debido a los múltiples y complejos factores controladores que lo influencian. Este trabajo explora dicha variabilidad en las sub-cuencas del valle de Aburrá (AV), enfocándose en los dos factores con mayor dominio en la HR a escala de evento: la precipitación detonante y las condiciones de humedad antecedentes. Para ello se comparó información hidrológica de nivel y precipitación de radar, con una resolución temporal fina, en 58 sub-cuencas dentro del área de estudio. A su vez, esta información fue contrastada con las principales características físicas de las subcuencas. Se realizaron también análisis de los registros de la primera red de humedad del suelo (SM) in-situ de la zona, que incluyó 7 sub-cuencas del AV, en comparación con la información de eventos de precipitación y crecientes. El análisis de los eventos de tormentas en el AV, exhibió una relación creciente entre las magnitudes de la precipitación acumulada y el nivel máximo alcanzado por las crecientes. El estudio sugiere que la manifestación de dicha relación es susceptible al tamaño de la muestra de eventos y a la metodología usada para identificar los mismos; al analizar con menos cantidad de eventos, las magnitudes de precipitaciones y crecientes no presentaron relaciones observables. Por otro lado, se encontró que al final de las temporadas de lluvia en el AV se necesitan menores magnitudes de lluvia para detonar crecientes, mientras que al final de las temporadas secas son necesarios eventos de precipitación de mayor acumulado. En contraste, los patrones encontrados respecto al rol de la precipitación en la HR, no presentaron relaciones observables con las principales características físicas de las sub-cuencas de interés. Respecto a la humedad del suelo, los análisis manifestaron relaciones crecientes entre los picos de SM y de las crecientes durante eventos de precipitación. Adicionalmente, se encontraron relaciones de umbral entre la precipitación acumulada y humedad del suelo máxima durante eventos de lluvia, así como entre las magnitudes pico de humedad del suelo y de las crecientes; ambos comportamientos de umbral asociadas a valores de similares SM. Estos hallazgos sugieren que al superar cierto umbral de humedad del suelo, los eventos de creciente más relevantes pueden presentar mayor probabilidad de ocurrencia. En general, los resultados de este estudio pusieron de manifiesto el rol de ambos factores controladores de la HR, la precipitación y las condiciones de humedad antecedente, en las subcuencas del Valle de Aburrá. Estos sugieren que el monitoreo de ambos factores es potencialmente útil para el entendimiento y la alerta temprana de eventos de creciente en el área de estudio. (Texto tomado de la fuente) The hydrological response (HR) of watersheds to storm events, is recognized as a quite variable process due to the multiple and complex controlling factors that can influence it. This work aims to explore this variability in the sub-basins within the Aburr´a Valley (AV) watershed, focused on the two most dominant factors regarding the HR: the triggering rainfall and the antecedent moisture conditions. To achieve this, we compared the hydrological information of water level and radar-derived precipitation, at a fine temporal scale, within 58 sub-basins in the study area. At the same time, these records were contrasted with the main physical features of the sub-basins. We also fulfilled an analysis of the first soil moisture network records in the zone, which include 7 of the AV sub-basins, in comparison to the precipitation and flood events. The analysis of the storm events within the AV exhibited an increasing relationship between the magnitudes of accumulated precipitation and the peak level reached by the floods. The study suggests that the display of that relationship is susceptible to the sizes of the events samples, as well as to the methodology used to identify them; in analysis with much fewer events, the magnitudes of rainfall and floods did not show perceptible relationships. On the other hand, it was found that at the end of the AV rainfall seasons, less rainfall is needed to trigger floods, while at the end of dry seasons, greater accumulated precipitation events are needed to trigger floods of similar magnitudes. In contrast, the patterns regarding the role of precipitation on the HR did not exhibit an observable relationship with the main physical features of the studied sub-basins. In regard to soil moisture, the analysis showed increasing relationships between the peaks of SM and floods during rainfall events. Additionally, threshold relationships were found between the accumulated precipitation and the peak soil moisture during events, as well as between the peak magnitudes of soil moisture and flood events; both threshold behaviors were found associated with similar SM values. These findings suggest that the most relevant flood events can be more probable if the soil moisture exceeds a certain threshold. In general, the results of this study exhibited the role of both HR controlling factors, rainfall and antecedent moisture conditions. They suggest the monitoring of both factors to be potentially useful for the understanding and the early warning of flood events within the study area. Maestría Magister en Ingeniería - Recursos Hidráulicos Área Curricular de Medio Ambiente

Floods are natural phenomena, inextricably related to river regimes, which can threaten human health and life, the environment, cultural heritage, economic activity and infrastructure. The aim of the research is to assess the connection between rainfall and river flood risk. The proposed methodology is presented on the example of the upper Nysa Kłodzka River (NKR) catchment and Kłodzko town located on NKR, which are two of the most flood-prone areas in the Odra River basin. The methodology is based on the well-established methods of potential flood losses (PFL) estimation and the copula-based model, allowing an assessment of connections between rainfall and flood losses in a probabilistic way. The results are presented using the ‘synchronicity’ measure. Seventeen significant summer (rainfall-driven) flood waves were selected, for which PFL were estimated and cumulative rainfall was calculated for 24, 48, 72, 96 and 120 h preceding the flood peak. It was found that the synchronicity of PFL and the 24 h rainfall was the lowest among the analyzed variants, while for the 48 to 120 h rainfall the highest synchronicity was identified at precipitation gauge Podzamek.

The advantages derived from the use of Uncrewed Aerial Vehicles (UAVs) are well-established: they are cost-effective and easy to use. There are numerous environmental applications, particularly when monitoring contexts characterized by rapid morphological changes and high rates of sediment transport, such as coastal areas. In this paper, three different case studies of survey and monitoring with high resolution and accuracy obtained through the use of UAVs are presented; these concern transgressive coastal sites. Results allow for the definition and quantification of coastal landforms and processes, including: (i) The anatomy of a parabolic dune and the rate of landward migration that could interfere with a tourist settlement; (ii) The mode and timing of morphological recovery and realignment of a barrier island overwashed by storm surge episodes; and (iii) The potential flood risk of a progradational spit that is a nesting site of a species of migratory breeding birds of conservation concern. The results demonstrate and confirm that, through a good coupling of drone-sensed quality data and accurate topographic control, quantitative estimates that are useful in assessing the impacts of natural processes involving both human and natural assets can be obtained.

The issue of spatial equity of Nature-Based Solutions in cities generally concerns the spatial distribution of their benefits to local residents and other city users. In the context of flood risk management, planners are challenged to identify effective mitigation and adaptation measures that can generate benefits to the higher number of people and, more specifically, to people with highest levels of exposure and vulnerability. To address these issues, an essential step is to identify the geography of needs for mitigation, intended as prior areas in which to locate measures for flood risk mitigation. This study combines geospatial layers of multiple dimensions of exposure and vulnerability to flooding and identifies prior areas suitable for design scenarios for mitigation of flooding risk, for a regional case study located in Sicily. The results show patterns of exposure and vulnerability that vary according to locally relevant physical and social urban dimensions. Based on these results, proposals for mitigation actions are advanced with the overall objective of generating equal benefits to the most vulnerable exposed social subjects. Moreover, this study argues about the particular implications of implementing stormwater green infrastructure planning for equal beneficial distribution of the potentially achievable risk reduction.

This study evaluates how the characteristics of daily rainfall and extreme events in Côte d’Ivoire changed during 1961–2015 using the rain gauge observation network of the National Meteorological Service (SODEXAM). The results indicate that the northern and southern parts of Cote d’Ivoire experienced a change from a wet to a dry period, with cut-offs in 1982 and 1983, respectively. In the northern part, this dry period was marked by a decrease in rainfall intensity, the length of wet spells, and the contribution of heavy and extreme rainfall, as well as an increase in the number of rainy days and a decrease in the length of dry spells. Over the southern part, this dry period was marked by an increase in the maximum length of dry spells associated with an increase in the maximum 1-day and 5-day precipitation events. The western part of Côte d’Ivoire experienced a late cut-off from the wet to dry period in 2000; the dry period was associated with a decrease in the number of rainy days, rainfall intensities, and maximum length of wet spells. Changes in the central part of Cote d’Ivoire presented high variability, and trends were less marked, even though a cut-off from a wet to dry period was detected in 1991. This study shows that Côte d’Ivoire, which is located in a subhumid and humid region and has an economy dependent on agriculture (especially cash crops, which comprise 60% of the GDP), is experiencing dry spells that are increasing in frequency and length. Combined with deforestation to increase production, this situation could lead to desertification and compromise the sustainable development goals of the country. The contribution of heavy rainfall was found to increase during the last 15 years, increasing the overall risk of floods, especially in urban areas where city authorities and populations are not prepared, thereby threatening infrastructure and human security.

[ES] El presente Trabajo Final de Máster consiste en el desarrollo de una metodología para el análisis de consecuencias derivadas de inundaciones y rotura de presa. Este análisis tendrá en cuenta tanto consecuencias económicas directas e indirectas derivadas de los daños producidos por el agua en los eventos de inundación y consecuencias sociales. Se estudiarán y compararán mediante una aplicación práctica tres metodologías diferentes, la metodología SUFRI, LifeSim y LifeSim simplificada mediante su aplicación a través del entorno de modelación del Hydrologic Engineering Center y sus software HEC-FIA y HEC-LifeSim así como su viabilidad para su aplicación al caso de presas españolas. El caso de aplicación será una presa de titularidad pública española., [EN] This Master's Final Project consists of the development of a methodology for the analysis of consequences derived from floods and dam failure. This analysis will take into account both direct and indirect economic consequences derived from the damage caused by water in flood events and social consequences. Three differents methodologies, SUFRI, LifeSim and simplified LifeSim will be studied and compared by means of a practical application through the modelling environment of the Hydrologic Engineering Center's HEC-FIA and HEC-LifeSim will be undertaken, as well as its feasibility to be applied in Spain. The case study will be a Spanish publicly owned dam.

The present work is aimed at assessing the change in time of flood risk as a consequence of landscape modifications. The town of San Donà di Piave (Italy) is taken as a representative case study because, as most parts of the North Italy floodplains, it was strongly urbanized and anthropized in the last several decades. As a proxy for flood risk, we use flood damage to residential buildings. The analysis is carried out at the local scale, accounting for changes to single buildings; GIS data such as high-resolution topography, technical maps, and aerial images taken over time are used to track how the landscape evolves over time, both in terms of urbanized areas and of hydraulically relevant structures (e.g., embankments). Flood hazard is determined using a physics-based, finite element hydrodynamic code that models in a coupled way the flood routing within the Piave River, the formation of levee failures, and the flooding of adjacent areas. The expected flood damage to residential buildings is estimated using an innovative method, recently proposed in the literature, which allows estimating how the damage evolves during a single flood event. The decade-scale change in the expected flood damage reveals the detrimental effect of urbanization, with flood risk growing at the pace of a fraction of urbanized areas. The within-event time evolution of the flood damage, i.e., how it progresses in the course of past or recent flood events, reflects changes in the hydrodynamic process of flooding. The general methodology used in the present work can be viewed as a promising technique to analyze the effects on the flood risk of past landscape evolution and, more importantly, a valuable tool toward an improved, well-informed, and sustainable land planning.

We study how professional investors capitalize flood risk in commercial real estate (CRE) markets after hurricane Sandy. We show that New York CRE exposed to flood risk trades at a large, persistent discount. CRE in Boston, which mostly escaped direct hurricane-related damage, also exhibits persistent price penalties. These price effects are driven by asset-level capitalization rates, not building occupancy. Results from a placebo test using real estate prices in Chicago show that our inferences are not driven by coincidental, unrelated price trends for waterfront real estate assets. Our results are consistent with professional investors responding to a persistent shift in the salience of flood risk post-Sandy, even in locations spared by the disaster.

The spatial transfer of flood damage models among regions and countries is a challenging but unavoidable approach, for performing flood risk assessments in data and model scarce regions. In these cases, similarities and differences between the contexts of application should be considered to obtain reliable damage estimations and, in some cases, the adaptation of the original model to the new conditions is required. This study exemplifies a replicable procedure for the adaptation to the Belgian context of a multi-variable, synthetic flood damage model for the residential sector originally developed for Italy (INSYDE). The study illustrates necessary amendments in model assumptions, especially regarding input default values for the hazard and building parameters and damage functions describing the modelled damage mechanisms.

Climate change, loss of biodiversity and degradation of ecosystems are all linked and have devastating consequences for our socio-economic stability, health and well-being. Working with nature is increasingly recognized as an efficient way to tackle these growing challenges, according to the new EEA report ‘Nature-based solutions in Europe: Policy, knowledge and practice for climate change adaptation and disaster risk reduction.’ In line with the basin wide updated flood risk strategy like International Commission for the Protection of the Danube River (hereafter: ICPDR) Flood Risk Management Plans 2021. Multilevel action plans have been developed. The EU level plans, such as the EU Strategy for the Danube Region, from the geographical point of view (for example: EU Green Deal) are mainly based on watersheds and on macro-regional scale. However, at the same time, counties should elaborate their strategies on their own level. Hungary has many strategies, one of the most relevant in terms of climate change is the Hungarian National Water Strategy (hereafter: HNWS), also known as, Kvassay Jenő Plan.

Continuous urban expansion, the conversion of open land to built-up areas and increased energy consumption have diversified the microclimates of cities. These phenomena combined with climate change hazards increase the vulnerability of cities, in a spatially heterogeneous way. Therefore, cities should become more resilient to those threats, by identifying and prioritising highly vulnerable areas. The main purpose of this study is to develop a spatial-based approach to assess the vulnerability of climate-related hazards in the urban environment of Thessaloniki (Greece). In this context, spatial and temporal patterns of land surface temperature were estimated through the calculation of various spectral indices, to conduct an analytical Urban Heat Island vulnerability assessment. Furthermore, the FloodMap-Pro application was used to identify coastal areas that are vulnerable to sea level rise, while historical floods were digitised in order to identify potential urban (flash) flood zones. The most important outcome of this paper is the creation of an integrated spatial vulnerability index, which identifies the urban areas that are prone to all these hazards. The final vulnerability map illustrates how the city of Thessaloniki is exposed to several climate-related hazards and that many areas/neighbourhoods are prone to one or more risk factors.

Especially in antiquity, rivers would both consist of a great resource, and they would exert a fearsome destructive power—vis cui resisti non potest, as Roman jurists used to assert. To prevent the risk of floods, Romans would not only carry out important public works, but also establish technical-juridical rules to induce both private individuals and communities to take care of the problem. Those rules were partly drawn up in public documents (such as praetorian edicta, leges dictae and so on), partly conceived by Roman jurists in a continuous debate starting at least from the first century AD to the third century AD and partly developed by discussions among Roman land surveyors.

Pluvial flooding causes significant damage in urban areas worldwide. The most common approaches to mitigating these impacts at regional scales include structural measures such as dams, levees and floodways. More recently, the use of nature-based solutions (NBS) is receiving increasing attention, as such approaches are more adaptive than structural measures and have a number of potential co-benefits (e.g., improvements in water quality and amenity). As NBSs are generally applied at house or block scales in urban areas, their potential for reducing the impacts of urban flooding at the regional scale are unknown. We introduce an approach that enables the potential of using portfolios of NBSs to reduce the impact of urban flooding to be assessed at the regional scale. This approach enables the most suitable locations for such portfolios of NBSs to be identified, as well as their effectiveness to be modeled at spatial resolutions that are commonly used for regional planning studies. The approach is applied to a case study area to the north of Adelaide, South Australia, with results obtained suggesting that there is significant potential for using strategically placed portfolios of NBSs to reduce the impact of pluvial flooding in urban areas at the regional scale.

Context and background Residing in areas of flood risk informal settlements is more or less normal among low-income households in most cities of the developing countries. While living in such settlements present challenge to quality of life, many among the urban poor offer these areas. Goal and objectives: This paper analyses factors that drive urban residents to acquire land and build houses in flood prone areas. Msasani Bonde la Mpunga in the city of Dar es Salaam was selected as a case study area. Methodology: Data were collected using household questionnaires, key informant interviews, focus group discussion (FGD) and field observations. Reasons for opting land in marginal areas including flood prone sites include; proximity to workplaces, easy and cheap land access, convenient access to social services, high Proximity to low rental prices, and connections to neighbours and friends. Other reasons include; stringent procedures such as urban planning and house construction standards to acquire planned plots, poverty and little awareness about flood risks areas. Results: Whilst the findings, reveal that home builders’ decisions are shaped by multiple factors, the paper calls for rethinking the strategies and opportunities for housing land delivery for low-income households in urban areas. Key words-Risk, flood risk, informal settlements, Land acquisition, residence, risky decisions., African Journal on Land Policy and Geospatial Sciences, Vol 6, No 1: January 2023

In the planning and design of natural and urban environments, visualization plays an increasingly important role. It has become a core component of communication and dissemination within the various formats of project representation, environmental assessment, workshops, and stakeholder involvement in general. However, as a practical technology, the outputs of our visualizations are, too often, regarded as a static product rather than as a living and evolving tool in and of itself, often due to the inherent restrictions present in both the analog and digital technologies used in data curation and visualization creation. In this paper, we argue that with the increasing complexity and usability of digital technologies, we are now capable of bringing a heightened level of interactive dynamism to planning and design, improving the communicative power of landscape visualization. We introduce a theoretical adaptive visualization (AV) framework, designed to support project meetings and stakeholder interactions with iterative planning and design elements. To demonstrate the merits of the framework, we develop an augmented reality application following AV principles; we discuss the novel design interactions afforded by integrating alongside traditional analog and digital data sources, in an interactive and dynamic application. This is highlighted by a case study from the Pearl River Delta region, with a focus on planning and design for flood risk mitigation.

The aim of this study is to analyse the effects of reservoir operating scenarios, for flood damage evaluation downstream of a dam, using a Monte Carlo bivariate modelling chain. The proposed methodology involves a stochastic procedure to calculate flood hydrographs and the evaluation of the consequent flood inundation area by applying a 2D hydraulic model. These results are used to estimate the inundation risk and, as consequence, the relative damage evaluation under different water level conditions in an upstream reservoir. The modelling chain can be summarized as follows: single synthetic stochastic rainfall event generation by using a Monte Carlo procedure through a bivariate copulas analysis; synthetic bivariate stochastic inflow hydrograph derivation by using a conceptual fully distributed model starting from synthetic hyetographs above the derived; flood hydrographs routing through the reservoir taking in an account of the initial level in the reservoir; flood inundation mapping by applying a 2D hydraulic simulation and damage evaluation through the use of appropriate depth-damage curves. This allowed for the evaluation of the influence of initial water level on flood risk scenarios. The procedure was applied to the case study of the floodplain downstream from the Castello reservoir, within the Magazzolo river catchment, located in the southwestern part of Sicily (Italy).

The article presents an analysis of the potential consequences for Cracow of failure of dams located in the Vistula catchment area upstream of the city. They have been compared with the effects of a flood with a probability of 0.2%. The estimation of losses and damages was made on the basis of the results of model studies and flood hazard and flood risk assessments carried out as part of the analyses of the second planning cycle of the implementation of the Floods Directive in Poland. The MIKE 11 model was used to simulate flows in riverbeds and its Dambreak module is used to simulate dam failure. An adjustment of the loss index for Cracow’s residential areas was proposed. Some elements of the described methodology can be used to estimate flood losses in large cities. They can also be applied to cities that are not at risk of dam disasters.

Since the beginning of the 21st Century, Europe has been affected by destructive floods. European Union Member States have an obligation to develop flood hazard and flood risk maps as support to the Flood Risk Management Plan (FRMP). The main objective of this study is to propose a methodological framework for hazard and risk assessment of pluvial flash floods in Croatia at the catchment level, which can be integrated into the FRMP. Therefore, a methodology based on the source–pathway–consequence approach for flood risk assessment is presented, which complies with the EU Floods Directive. This integrated and comprehensive methodology is based on high-resolution open data available for EU Member States. Three scenarios are defined for a low, medium, and high probability, defined by design storms of different durations. The proposed methodology consists of flood hazard analysis, vulnerability assessment, and risk analysis. Pluvial flash flood hazards are analyzed using a 2D hydrologic–hydraulic model. The flood vulnerability assessment consists of a GIS analysis to identify receptors potentially at risk of flooding and an assessment of susceptibility to potential flood damage using depth–damage curves. Flood risk is assessed both qualitatively in terms of risk levels and quantitatively in terms of direct damages expressed in monetary terms. The developed methodology was applied and tested in a case study in the Gospić catchment in Croatia, which surrounds a small rural town frequently affected by pluvial flash floods.

Since the beginning of the 21st Century, Europe has been affected by destructive floods. European Union Member States have an obligation to develop flood hazard and flood risk maps as support to the Flood Risk Management Plan (FRMP). The main objective of this study is to propose a methodological framework for hazard and risk assessment of pluvial flash floods in Croatia at the catchment level, which can be integrated into the FRMP. Therefore, a methodology based on the source–pathway–consequence approach for flood risk assessment is presented, which complies with the EU Floods Directive. This integrated and comprehensive methodology is based on high-resolution open data available for EU Member States. Three scenarios are defined for a low, medium, and high probability, defined by design storms of different durations. The proposed methodology consists of flood hazard analysis, vulnerability assessment, and risk analysis. Pluvial flash flood hazards are analyzed using a 2D hydrologic–hydraulic model. The flood vulnerability assessment consists of a GIS analysis to identify receptors potentially at risk of flooding and an assessment of susceptibility to potential flood damage using depth–damage curves. Flood risk is assessed both qualitatively in terms of risk levels and quantitatively in terms of direct damages expressed in monetary terms. The developed methodology was applied and tested in a case study in the Gospić catchment in Croatia, which surrounds a small rural town frequently affected by pluvial flash floods.

Morje nam prinaša veliko priložnosti – razvoj obmorskih mest in industrije, ki je vezana na morje. Lahko pa predstavlja tudi oviro - vse hitrejša rast gladine morja mestom grozi z vse več poplavami. Propad proizvodnih dejavnosti na slovenski obali je posledično ustvaril obširne degradirane in razvrednotene površine ter že desetletja opuščena zemljišča s propadajočo naravno in kulturno dediščino. Degradirana urbana območja so priložnost za notranji razvoj in prenovo mestnega središča. Prav tako so lahko ustrezne urbane in arhitekturne rešitve odgovor na vse bolj prisotne posledice globalnega segrevanja. Magistrska naloga obsega raziskavo teme (degradiranih industrijskih urbanih območij in regeneracijo le teh ter problematiko poplavne ogroženosti s primeri dobre prakse) in kraja ter samega območja obravnave. Sledijo analize prostora in mnenj odločevalcev urejanja prostora (občina Izola in ZVKDS Piran) ter ankete izvedene z domačini. Vse to je osnova za koncept razvoja obravnavanega območja. Cilj magistrske naloge je revitalizacija območja nekdanje tovarne Argo (tudi Arrigoni, Droga) in Riba (tudi Degrassi) v Izoli. Idejna zasnova obravnava javne vsebine ter umestitev nove družbene infrastrukture v odnosu do obstoječe. Magistrsko delo obsega urbanistično ureditev obravnavanega območja nekdanjih tovarn Argo in Riba ter arhitekturno zasnovo kulturnega centra kraja. Ureditev rešuje tudi problematiko poplavne ogroženosti obravnavanega območja. Novo družbeno središče na robu starega mestnega jedra dopolnjuje obstoječe vsebine, hkrati pa se vzpostavi novo kulturno in upravno središče mesta. The sea brings us many new opportunities - the development of coastal towns and the industry that is connected to the sea. However, it can also represent an obstacle - the rising sea levels, many coastal towns are in flood danger. The collapse of the industry at the Slovenian coast created many degraded areas and infrastructure that used to have a rich cultural history have been slowly declining for the past two decades. Degraded urban areas present us with an opportunity for an internal development and the rejuvenation of old town centers. Furthermore, architectural and urban solutions could be the answer to the environmental issues, that are caused by global warming. The master thesis is a research into the topic (The degradation of industrial areas and the regeneration of these areas, it also deals with flood danger), the town and the focused area. In the thesis there are analyses of the area and opinions of the county of Izola and ZVKDS Piran. The aforementioned serves as a foundation for the concept of the development of the area. The goal of this master thesis is the revitalization of the area that was once an industrial complex Argo (also Arrigoni, Droga) and Riba (also Degrassi) located in Izola. The conceptual design deals with public content and the placement of a new social infrastructure in relation to the existing one. The Master thesis encompasses the urban planning of the area, that was once the industrial complex and the architectural design of cultural center. The plan also tackles and solves the problems of flooding of the focused area. The new social center, on the edge of the old town center, completes the existing landscape and at the same time establishes a new cultural town center.

У раду се даје кратак приказ холистичког приступа смањењу ризика од поплава помоћу природи блиских решења. Овакав приступ узима у обзир не само смањење ризика као основни циљ мера заштите од поплава, већ и друге циљеве заједнице као што су заштита животне средине, добробит и здравље људи и друштвено-економски развој. На примеру слива реке Тамнаве, а као резултат истраживачког рада у међународном пројекту RECONECT у оквиру H2020 програма ЕУ, приказују се прелиминарни резултати примене овог концепта уз разматрање неколико сценарија могућих мера заштите и користи које оне могу донети у погледу смањења ризика од поплава и унапређења екосистемских услуга на сливу. Приказана методологија укључује новчано вредновање ефеката мера са гледишта смањења ризика (избегнутих штета), као секундарних ефеката од смањења ерозије додатним пошумљавањем. Ово друго вредновање је такође искоришћено за прелиминарну процену свих релевантних екосистемских услуга на сливу, што указује на вредност природног капитала овог слива. Овакве процене су важне за процес доношења одлука о мерама заштите од поплава. This paper presents briefly a holistic approach to reducing flood risks using the nature-based solutions. This approach takes into account not only the reduced risk as the primary goal of flood mitigation, but also involves other goals such as the protection of the environment, human well-being, socio-economic goals etc. The Tamnava River basin is used as a pilot case to demonstrate the methodology of such an approach, resulting from the work within the RECONECT project from the EU Horizon 2020 programme. The paper presents preliminary results for the Tamnava River basin by considering several scenarios for flood mitigation measures and potential benefits from these measures in flood risk reduction and in improved ecosystem services in the basin. The methodology includes monetary valuation of the effects of the proposed flood mitigation measures in terms of the avoided damages, as well as of the secondary benefits from the erosion control by additional afforestation. The latter also provides basis for preliminary valuation of all relevant ecosystem services in the basin, thus indicating the value of the basin’s natural capital. Such an evaluation is important for the decision-making process on possible flood mitigation strategies. Рад је добио Награду за најбољи научни рад са Прве меморијалне научно-стручне конференције ,,Предраг Марић". Конференција је одржана 11.2.2022. године. у просторијама Института за међународну политику и привреду, Македонска 25, у Београду. Годишњак Факултета безбедности 2022 (Faculty of Security Studies Annual), издавач Факултет безбедности Универзитета у Београду; адреса - Господара Вучића 50, Београд; обим 434 стране, штампани тираж 100 примерака, припрема и штампа ,,Чигоја штампа". Категорија часописа - M52. UDK 556.166(282)(497.11) COBISS.SR-ID 112460809 https://aseestant.ceon.rs/index.php/fb_godisnjak/article/view/37341/22674

Nature-based solutions (NbS) are a cornerstone of climate change adaptation worldwide. Yet, evidence on their economic benefits is scarce, especially since the provided environmental amenities usually spatially correlate with climate-induced hazards, effects of which NbS aim to curb. This lack of empirical evidence creates obscurity regarding social acceptability of NS, hindering their uptake and upscaling. We apply hedonic price models to estimate homeowners' willingness-to-pay for NbS (like flood safety, environmental benefits), while controlling for spatio-temporal changes in capitalized flood risk discounts due to the 1993-1995 floods in the Limburg Province, the Netherlands. We reveal a pre-flood effect of 5.6% (discounting on average -€12,753 for flood-prone properties), which rises to 10.9% (−€24,691 on average) immediately after the floods. However, the effect is only transitory. The flood discount of home values price discount diminishes over time and eventually vanishes in 9–12 years, which coincides with the implementation of the largest and oldest NbS intervention in the Netherlands. Our analysis shows that NbS amenities provide a 15% (€33,687 on average) premium to nearby residential property prices. This evidence of the evolving flood risk discount and the stable NbS premium for individual homeowners could support the economic feasibility and wide acceptability of NbS for climate change adaptations.

Around 45% of natural hazards reported worldwide are related to floods, andcurrent indications show that exposure to floods and inherent losses will keepescalating. Historic centres are particularly vulnerable in this context due tothe structural and material characteristics of the buildings and because theyembrace social and cultural values that must be safeguarded. This article aimsto contribute to this research area by presenting and discussing the applicationof an index-based methodology specifically tailored to assess flood risk in his-toric urban centres. The historic city centre of Tomar, Portugal, an area thatencompasses over 500 buildings and has a rich history of floods, is used hereas a case study. Vulnerability data resulting from the application of the vulner-ability assessment approach are then combined with flood hazard—that is,water velocity and depth obtained from flood peaks estimated for 20- and100-year periods of return—and used to identify the buildings at risk. Finally,a set of depth-damage curves is derived and used here to carry out a cost–benefit analysis for different flood adaptation measures.

Climate change poses the most pressing global challenge in recent history. The risks associated with climate change do not only pertain to the rise in temperature, but the accompanying changes in the meteorological and hydrological properties of the planet. Climate change’s impact on the established communities is vast and visible, affecting the functionality of societies on a multitude of ways, and increasingly causing cascading failures and systemic risks (i.e., failures resulting from the interdependent nature of our society systems). This is aggravated by the expansive development of urban areas into exposed, hazard-prone regions. One of the costliest and most frequent hazards resulting from climate change is flood hazard, with its increasing severity and frequency due to the coupling of the aforementioned reasons. This thesis aims at enhancing the resilience of the exposed communities to climate change-induced hazards, with a focus on flood risk, to develop pertinent realistic, proactive, resilience-informed risk management plans. The thesis applies machine learning and data analytics to understand, quantify, and eventually predict climate change-induced flood risk. Descriptive analytics techniques were employed to understand the extent of flood risk on urban communities, resulting in a categorization of the different community responses to flood risk. This categorization is subsequently employed in developing predictive analysis, where global climate models are utilized to predict the changes of the resilience of the exposed communities until the year 2050. Said studies, while revolutionary in nature, serve as a steppingstone in developing a comprehensive, proactive, global disaster management plan. Finally, the thesis narrows its scope by focusing on operationalizing the developed climate resilience methodology considering a single critical infrastructure network and enhances the climate resilience of its risk management plan, set, and operated by its asset owners and decision makers. The approaches developed herein were applied on different datasets for vulnerability identification, loss and resilience prediction, and policy improvement resulting in an overall climate resilience-informed enhancement of the current risk management practices. Thesis Doctor of Philosophy (PhD) Climate change poses the most pressing global challenge in recent history, with a vast impact on the functionality of the established communities in a multitude of ways, increasingly causing cascading infrastructure failures. This is aggravated by the expansive development of urban areas into exposed, hazard-prone areas, one of the costliest hazards being floods, with its increasing severity and frequency. This thesis aims at enhancing the climate-resilience of communities exposed to climate change-induced hazards, with a focus on flood risk, to develop realistic, proactive, resilience-informed risk management strategies. The thesis applies i) machine learning and data analytics to understand, quantify, and eventually predict the impact of climate change-induced flood risk, ii) descriptive analytics techniques to identify community and infrastructure vulnerabilities and exposure, iii) predictive analytics to predict future changes of community resilience until the year 2050. To operationalize its findings, the thesis also investigates and enhance the climate resilience of individual critical infrastructure systems and improve its risk management plans.

Risk-estimation models for urban areas generally fail to consider the psychological factors that affect human response to risk. The present contribution aims to integrate key psychological factors in models assessing the potential economic consequences of flood-related events. Specifically, the work focused on the resilient near-miss effect, the human tendency to underestimate the risks when a previous negative outcome is avoided by chance. Study 1 (N = 241) investigated the resilient near-miss effect among residents of both flood-prone and safe areas, showing that participants exposed to near-miss scenarios perceived a lower level of risk and damages regardless of their past experience with the hazard and were thus less prone to adopt protective measures. Based on the data collected in Study 1, Study 2 developed a series of agent-based models to simulate the effect of experiencing near-miss events on a neighborhood in a flood-prone area, where inhabitants have to decide whether to purchase insurance against flood-related damage. The agent-based models integrating the psychological parameters revealed that the underestimation of the likelihood of flooding due to the near-miss effect is likely to increase the negative economic consequences of natural disasters suffered by the population. Integration of psychological variables might be a promising way to increase the accuracy of risk estimation models, especially when relying on data collected from the population of interest.

Background: The rise in global temperatures and the general effect of climate change, contributes to an increased flooding risk. Especially in communal safety work for Gothenburg and Karlstad, flood managing is high up on the priority list. The high level of threat that these two cities experience, is given by the fact that they are surrounded by water. The countermeasures that have taken place, must live up to the concept of sustainable development, since the primary cause of floods is climate change which has extremely long-time references. These strategies have to adapt for risks with broad time-frameworks, but this might generate other consequences of their own. This never-ending cycle of risks is a paradox called levée-effect affects human behaviour on decision-making level and also in the general public. The levée-effect causes people to feel a false sense of security behind a countermeasure for and will consequently lead to a lowered preparedness for it. Purpose: The purpose of this study is to delve into the communal work with floods countermeasures and how these reacts with the theory on the levée-effect. Method: The method used to complete this study is a case study of specific countermeasures used to protect vulnerable places in Gothenburg and Karlstad from floods. The primary data collection has been in the form of interviews with relevant personnel from the two cities and their respective county administrative. As a complement to the interviews, a thorough content analysis of relevant communal documents has been made for the purpose of strengthen or deny the interviews. Results: Based on the results of the analysis, the two cities have been adapting according to a long time-references for the purpose of counter act the effects of climate change. This causes other kinds of problems though, since too long of a time-reference will cause peoples risk-awareness to be affected and the levée-effect to further show its effects. For example, society can feel way to comfortable and safe behind a countermeasure from a risk, that their preparedness towards it will lower consequently. Conclusion: From the discussion of the study’s result, more than one conclusion can be drawn. Both Gothenburg and Karlstad, with their flood countermeasures, live up to a sustainable development which relies on a good knowledge and climate awareness. There is more than one challenge identified with this strategy which can be partially attributed to conflicts between decision-makers and other players which also affects the sustainability and safety levels of the city. Another challenge can be partially attributed to a lowered preparedness as a result of the construction of countermeasures for flood-management.

Floods are frequent natural hazards, triggering significant negative consequences for the economy every year. Their impact is expected to increase in the near future due to socio-economic development and climate change. In order to minimize the probability and magnitude of expected economic losses and compensation costs, it is essential that flood risk managers are properly informed about potential damage related to hazard features and exposure. In this paper, a flood damage estimation method was proposed for the assessment of flood risk in the Drammen River basin by using a hydraulic model, GIS, and a flood loss estimation model. Hazard variables such as flood depth, flood extent, and flood velocity were computed for the current and future climatic scenarios using the hydraulic model for flood damage assessment. To visualize the flood extent, velocity, depth, and their impact, the results of modelling are illustrated in the form of flood inundation maps produced in GIS. A flood loss estimate included buildings and other infrastructure that are major exposures in flood-prone areas. The flood damage model is formulated based on stage–damage relationships between different flood depths and land-use categories. It calculates the economic loss related to different land-use features based on the simulated flood parameter obtained from the hydraulic model from 100- to 1000-year return periods. For the case study, the results show that the highest proportion of the total damage in each repetition interval (approximately 90–92%) is expected to occur in buildings. In addition, results showed that the effects of climate change will raise the total damage from floods by 20.26%.

Evidence are dearly needed to understand under which conditions it is relevant for decisions makers to invest in NBS for water-related risk. This chapter presents the methodological framework developed for the economic assessment of NBS for water-related risks and its application to seven case studies. We particularly develop methods for the evaluation of implementation and opportunity costs, the assessment of the reduction of damage costs, and the monetary value of co-benefits. The study confirms that the cost of implementation and maintenance of NBS strategies is lower than the cost of grey solutions for the same level of water risk management, emphasizing the better cost-effectiveness of these solutions. Benefits in terms of avoided damages are however generally not sufficient to cover investment and maintenance costs. Co-benefits represent the largest share of the value generated by NBS strategies. The overall cost-benefit analysis implemented in four cases, is positive in three case studies and negative in one. This confirms the importance to carry out thorough economic assessments for the elaboration of Natural Assurance Schemes.

The Lez catchment is characterized by a rapid urbanization, due to the attractiveness of the city of Montpellier, and is exposed to a typical Mediterranean weather with high risk of flash flood and other emerging issues, such as air pollution, heat island effects and biodiversity losses. We present the evaluation of two types of NBS to address these challenges, (i) urbanization strategies that have an impact on the conservation of agricultural and natural land and (ii) a network of green infrastructure (GI), with a focus on the economic analysis. Our results reveal that our most ambitious GI strategy can reduce up to a 20% of the mean annual damages due to annual flood damages. The largest share of the economic value of our NBS however lies in the co-benefits they generate. Overall, the two GI strategies present a positive cost-benefit analysis. We finally identify a pathway towards implementation in terms of financing and organizational challenges.

Bujične poplave nastaju kao posljedica kratkotrajnih oborina velikog intenziteta ili uslijed puknuća/kvara hidrotehničkog objekta ili opreme. Karakterizira ih iznenadna lokalna poplava velikog volumena i kratkog trajanja koja nastaje u razdoblju od nekoliko, obično manje od šest, sati od jake kiše. Posljednjih godina, kao posljedica klimatskih ekstrema, bujične poplave su sve češća pojava pa i na područjima gdje se do sada nisu pojavljivale. Kroz upravljanje rizicima od poplava potrebno je dodatnu pažnju usmjeriti upravo na ovaj tip poplava jer su izuzetno opasne te mogu izazvati velike štete na imovinu i ljude. Kroz aktivnosti na lokalnoj razini bitno je educirati stanovništvo i osvijestiti na moguću opasnost od bujičnih poplava. Također potrebno poduzeti potrebne mjere kako bi se smanjili rizici od bujičnih poplava., Flash floods occur as a result of short-term, high-intensity precipitation or as a result of a failure of a hydrotechnical facility or equipment. They are characterized by a short duration and sudden local flood of large water volume that occurs within a period of several, usually less than six, hours from heavy rain. In recent years, as a result of climate extremes, flash floods are becoming more common, even in areas where they have not occurred before. It is necessary to focus extra attention on this type of floods, through flood risk management, because they are extremely dangerous and can cause damage to property and people. Through activities at the local level, it is important to educate the population and make them aware of the possible danger of flash floods. It is also necessary to take the necessary measures to reduce the risks of flash floods.

Τα συχνά πλημμυρικά φαινόμενα στην Ελλάδα σε συνδυασμό με τη μη ικανοποιητική αντιπλημμυρική θωράκιση, οδηγούν σε καταστροφές με υλικές ζημιές, υποβάθμιση του περιβάλλοντος και ανθρώπινα θύματα. Η παρούσα διπλωματική εργασία έχει σαν σκοπό να διερευνήσει την πλημμυρική επικινδυνότητα του χειμάρρου Βελβεντού Κοζάνης για 50 και για 1000 έτη επαναφοράς, προσομοιώνοντας τη ροή του χειμάρρου με πλάτος διατομών 150 και 300 μέτρα στην πεδινή περιοχή. Γίνεται χρήση των λογισμικών ArcMap 10.7.1, ArcGIS Pro, και HEC-RAS 6.3.1. Υλοποιήθηκαν δύο υδρολογικές αναλύσεις με χρήση της ορθολογικής μεθόδου και στη συνέχεια τέσσερις υδραυλικές προσομοιώσεις με χρήση του λογισμού HEC-RAS για τους συνδυασμούς περιόδων επαναφοράς και πλάτους διατομών, με παραγωγή και σχεδιασμό γραμμών πλημμύρας. Παρά τη χαμηλή ακρίβεια (κανάβου πλευράς 5m) του Ψηφιακού Υποβάθρου Υψομέτρων (DEM) του Ελληνικού Κτηματολογίου, τα αποτελέσματα είναι αρκετά αξιόπιστα, δεδομένου ότι πολλές πραγματικές αντίστοιχες μελέτες διεξάγονται με τέτοια ανάλυση, και με ιδιαίτερο ενδιαφέρον. Η πεδινή περιοχή κινδυνεύει να πληγεί από πλημμύρες περισσότερο από την ορεινή περιοχή, τόσο για 50 όσο και για 1000 έτη επαναφοράς και για τις δύο περιπτώσεις πλάτους διατομών. Εκτός από προτάσεις βελτίωσης και συνέχισης της παρούσας μελέτης/έρευνας, όπως χρήση ακριβέστερου DEM ή/και ακριβέστερη αποτύπωση του χειμάρρου με επιτόπιες τοπογραφικές μετρήσεις και μη επανδρωμένα αεροχήματα, κατατίθενται και ρεαλιστικές προτάσεις για την καλύτερη αντιπλημμυρική θωράκιση της περιοχής, ενώ προτείνεται και σχετική επικαιροποίηση της νομοθεσίας, Recurring flood events in Greece combined with unsatisfactory flood protection, lead to disasters with material damages, environmental degradation and human casualties. The current Master Thesis aims to investigate the flood risk of the Velventos torrent in Kozani, Greece for return periods of 50 and 1000 years, simulating the torrent’s flow for the cross-sections’ width of 150 and 300 m in the lowland area of the hydrographic network. For that purpose, the following software applications were used: ArcMap 10.7.1, ArcGIS Pro, and HEC-RAS 6.3.1. Two hydrologic analyses were implemented using the rational method, followed by four hydraulic simulations using HEC-RAS for all combinations of return periods and cross-section widths, resulting at the production and design of the flood extents. Despite the low accuracy (5m x 5m grid) of the Digital Elevation Model (DEM) of the Hellenic Cadastre used, results are quite reliable, given that many respective real projects are implemented using similar accuracy, and also are quite interesting. The lowland torrent area is in higher risk of flooding than the mountainous ones, for both 50- and 1000-year return periods and for both applied cross-section widths. Apart from future research goals, such as the use of a more accurate DEM or/and a better mapping of the torrent with in-situ topographic survey methods and unmanned aerial vehicles, realistic suggestions are submitted towards improved flood protection of the study area, while the respective update of the relevant legislation is proposed

Storm surge barriers are large movable hydraulic structures which close during a storm surge to prevent coastal floods. In the regions they protect, a failure to close the barrier is often the most likely cause for a catastrophic flood. Nevertheless, flood risk assessments usually only focus on raising flood defences behind the barrier. Despite its importance, there is no general method to assess the costs and benefits of improving the closure reliability. This paper presents a model that optimises investments considering both closure reliability improvements and raising flood defences behind the barrier, using the region protected by the Maeslant barrier as a case. We substantiate that constructing the Maeslant barrier was an optimal economic decision. Moreover, we demonstrate large investments such as a redundant barrier already being economically sound with a few decimetres of sea level rise. Based on our experience with this case study, we expect the model is useful in finding strategies to adapt to rising sea levels and other developments that cause coastal flood risk to rise worldwide.

The effects of climate change are already being felt today, and future effects, which will be determined by the readiness and resolve of today’s world leaders, are fraught with high levels of complexity, uncertainty, ambiguity, and transboundary effects – characteristics of systemic risk. Since climate change is seen as a threat multiplier, the risks that might be impacted by climate change, such as floods and dam failure, will be affected by systemic risk characteristics as well. Recent literature on risk governance calls for a more inclusive approach to address the challenges of systemic risks. Sweden has adopted the Sendai Framework, which aims to reduce disaster risk and strengthen societal resilience through a more people-centered approach. Sweden can be expected to have the resources and institutional structures needed to be able to implement the framework at a high level. However, evaluations of recent crises have shown a discrepancy between what can be expected and actual performance. This thesis aims to increase the understanding of contextual barriers to and drivers of inclusive risk governance, with a focus on responsibilities, (mandated) collaboration, and stakeholder participation, as an approach to increase societal resilience against disaster and systemic risk. The aim is reached by studying flood-related systemic risks and their governance. Three distinct, qualitative case studies focusing on different aspects of the Swedish disaster risk reduction and risk governance systems in relation to the risk of floods and dam failure are the empirical foundation for the four papers that are appended in the thesis. The thesis concludes that there is a need for a change in how resilience is framed, as part of a paradigm shift to a discourse that views resilience as a measure of adaptive capacity, and a change in how systemic risks should be understood and governed, as part of a paradigm shift to an inclusive risk governance framework. Effekterna av klimatförändringarna märks idag, och framtida effekter, som avgörs av beslutsamheten hos dagens ledare, har höga nivåer av komplexitet, osäkerhet, tvetydighet och effektöverskridande – egenskaper hos systemrisker. Eftersom klimatförändringar ses som en hotmultiplikator kommer de risker som kan påverkas av klimatförändringar, såsom översvämningar och dammbrott, också att påverkas av systemriskegenskaper. Nylig litteratur om riskstyrning föreslår ett mer inkluderande tillvägagångssätt för att hantera utmaningarna med systemrisker. Sverige har antagit Sendai Framework, som syftar till att minska katastrofrisken och stärka samhällelig motståndskraft genom ett mer människocentrerat förhållningssätt. Sverige kan förväntas ha de resurser och institutionella strukturer som behövs för att kunna implementera ramverket på hög nivå. Utvärderingar av kriser det senaste årtiondet har dock visat att det finns en diskrepans mellan vad som kan förväntas och faktisk prestation. Syftet med denna avhandling är att öka förståelsen för kontextuella hinder och drivkrafter för inkluderande riskstyrning, med fokus på ansvar; (obligatorisk) samverkan; och intressentdeltagande, som ett tillvägagångssätt för att öka samhällets resiliens mot katastrofer och systemrisker. Målet nås genom en studie av översvämningsrelaterade systemrisker och deras styrning. Tre distinkta, kvalitativa fallstudier som fokuserar på olika aspekter av de svenska katastrofriskreduktions- och riskstyrningssystemen i relation till översvämningsrisk och risk för dammbrott är den empiriska grunden för de fyra artiklar som ligger till grund för avhandlingen. Slutsatsen av avhandlingen är att det finns ett behov av en förändring av hur resiliens betraktas, som en del av ett paradigmskifte till en diskurs som ser resiliens som ett mått på anpassningsförmåga, och en förändring av hur systemrisker ska förstås och styras, som del av ett paradigmskifte till ett ramverk för inkluderande riskstyrning. This thesis aims to increase the understanding of contextual barriers to and drivers of inclusive risk governance, with a focus on responsibilities, (mandated) collaboration, and stakeholder participation, as an approach to increase societal resilience against disaster and systemic risk. The aim is reached by studying flood-related systemic risks and their governance. Three distinct, qualitative case studies focusing on different aspects of the Swedish disaster risk reduction and risk governance systems in relation to the risk of floods and dam failure are the empirical foundation for the four papers that are appended in the thesis. The thesis concludes that there is a need for a change in how resilience is framed, as part of a paradigm shift to a discourse that views resilience as a measure of adaptive capacity, and a change in how systemic risks should be understood and governed, as part of a paradigm shift to an inclusive risk governance framework.

State-of-the-art flood hazard maps in coastal cities are often obtained from simulating coastal or pluvial events separately. This method does not account for the seasonality of flood drivers and their mutual dependence. In this article, we include the impact of these two factors in a computationally efficient probabilistic framework for flood risk calculation, using Ho Chi Minh City (HCMC) as a case study. HCMC can be flooded subannually by high tide, rainfall, and storm surge events or a combination thereof during the monsoon or tropical cyclones. Using long gauge observations, we stochastically model 10,000 years of rainfall and sea level events based on their monthly distributions, dependence structure and cooccurrence rate. The impact from each stochastic event is then obtained from a damage function built from selected rainfall and sea level combinations, leading to an expected annual damage (EAD) of $1.02 B (95th annual damage percentile of $2.15 B). We find no dependence for most months and large differences in expected damage across months ($36–166 M) driven by the seasonality of rainfall and sea levels. Excluding monthly variability leads to a serious underestimation of the EAD by 72–83%. This is because high-probability flood events, which can happen multiple times during the year and are properly captured by our framework, contribute the most to the EAD. This application illustrates the potential of our framework and advocates for the inclusion of flood drivers' dynamics in coastal risk assessments.

Conventional green roofs have often been criticised for their limited water buffer capacity during extreme rainfall events and for their susceptibility to droughts when additional irrigation is unavailable. One solution to these challenges is to create an extra blue water retention layer underneath the green layer. Blue-green roofs allow more stormwater to be stored, and the reservoir can act as a water source for the green layer throughout capillary rises. An automated valve regulates the water level of the system. It can be opened to drain water when extreme precipitation is expected. Therefore, the water buffer capacity of the system during extreme rainfall events can be maximised by integrating precipitation forecasts as triggers for the operation of the valve. However, the added value of this forecast-based operation is yet unknown. Accordingly, in this study, we design and evaluate a hydrological blue-green roof model that utilises precipitation forecasts. We test its performance to capture (extreme) precipitation and to increase evapotranspiration and evaporative cooling under a variety of precipitation forecast-based decision rules. We show that blue-green roofs can capture between 70 % and 97 % of extreme precipitation (>20 mm/h) when set to anticipate ensemble precipitation forecasts from the European Centre for Medium-Range Weather Forecasts (ECMWF). This capture ratio is considerably higher than that of a conventional green roof without extra water retention (12 %) or that of a blue-green roof that does not use forecast information (i.e., valve always closed; 59 %). Moreover, blue-green roofs allow for high evapotranspiration rates relative to potential evapotranspiration on hot summer days (around 70 %), which is higher than from conventional green roofs (30 %). This serves to underscore the higher capacity of blue-green roofs to reduce heat stress. Using the city of Amsterdam as a case study, we show the high upscaling potential of the concept: on average, potentially suitable flat roofs cover 13.3 % of the total area of the catchments that are susceptible to pluvial flood risk. If the 90th percentile of the ECMWF forecast is used, an 84 % rainfall capture ratio can translate into capturing 11 % of rainfall in flood-prone urban catchments in Amsterdam.

The traditional regulatory and policy approach to flood risk in the US has been the optimization of benefits and costs, broadly mandated by federal policy. However, optimization may not be the best approach to flood risk management in light of the deep uncertainties we now face. A more incremental approach using a satisficing strategy may be. Flood risk is a function of the hydrologic factors that produce a hazard and the consequences of the hazard interfacing with the people and property exposed. Regretfully, both hydrologists and climatologists seem unable to provide the clairvoyant guidance needed by the water community facing major decisions on flood risk management in the coming years. As the seminal ‘Red Book’ noted, two things have become second nature to policy analysts and risk managers: absolute safety is unachievable, and it is necessary to distinguish between science and policy. The forcing elements and largest unknowns in determining risk rest with understanding the hydrologic factors involved in shaping the hazard. HIGHLIGHTS Flood risk is a function of hazard, exposure, and vulnerability.; Hydrologists and climatologists seem unable to provide guidance for coming years.; The US operates with an inconsistent approach to dealing with hydrologic factors.; Quantitative risk analysis may not be the best approach considering the deep uncertainties such analyses face.; A more incremental and satisficing one may be.

Following Hurricane Katrina, the US Army Corps of Engineers, supported in part by the risk and reliability analysis conducted by the Interagency Performance Evaluation Task Force (IPET), made a major shift from ‘protection’ to ‘risk reduction’ as the principal goal in flood mitigation. The mitigation of the flood risk in Southeast Louisiana was embodied in the design and construction of the ‘Hurricane and Storm Damage Risk Reduction System’, the post-Katrina initiative for New Orleans flood mitigation. It also spawned a major overhaul of many of the Corps of Engineers’ technical guidance and engineering practice documents, incorporating risk as a key measure in the planning and design processes. The criteria applied for the design of the HSDRRS are discussed, with summaries of the associated major changes in Corps engineering guidance and practice relevant to flood mitigation. HIGHLIGHTS The losses from Hurricane Katrina and subsequent forensic and risk analyses for New Orleans resulted in substantial changes to the knowledge base and guidance for planning and designing coastal risk reduction systems.; The new knowledge was a substantial input to the design of the Hurricane and Storm Damage Risk Reduction System that is currently in place in New Orleans.; The processes used were considerably different from past practice and resulted in a more robust and resilient system with some capacity to deal with uncertainty and change. This paper highlights the new processes.; The same knowledge base was the stimulus for significant changes to the US Army Corps of Engineers engineering guidance and practice documents. A major change was the incorporation of risk-based decision making in many aspects of project development and execution.

A systems perspective is presented of what happened during and after Hurricane Katrina (2005) and the potential for reducing the likelihood of large losses in the future. This work was the basis for the rapid repair of the damage resulting from Katrina and ultimately the development and construction of a new risk reduction system for the region and a major shift in engineering guidance and practice related to public water infrastructure. The work was primarily accomplished through the Interagency Performance Evaluation Task Force (IPET) established by the Chief of Engineers, US Army Corps of Engineers, to conduct a comprehensive forensic analysis of what happened and why, and to an engineering risk and reliability assessment of the hurricane protection system in place when Katrina struck. HIGHLIGHTS Hurricane Katrina caused extensive and unprecedented economic damages and loss of life in Southeast Louisiana. An interagency task force was formed to find out what happened and why.; The resulting forensic analysis of the storm and resulting forces, protective structures and their performance, the resultant flooding, and associated economic and life losses portrays a vivid picture of the consequences of being unprepared.; The associated risk and reliability analysis conducted for New Orleans and vicinity provided a strategic baseline for understanding why New Orleans was so vulnerable and a foundation for configuring both short-term repairs and a longer-term initiative for a dramatic reduction of flood risk for the future.; The lessons learned from this effort were the roots of major changes in the approach taken for flood mitigation through the application of risk and reliability and a better understanding of both the hurricane threat and the failure modes of coastal structures.

Bangladesh is situated at the confluence of GBM basins, with 90% of the basin area locating outside the country. Future climate change will lead to intense, prolonged, and frequent floods in Bangladesh. An integrated flood risk assessment that transforms flood risks from transboundary river basins to the local administrative level is necessary. A 1D/2D hydrodynamic model is developed for flood vulnerable Arial Khan River feed by basin-scale hydrologic model for low (RCP2.6) and high (RCP8.5) climate scenarios. An increasing trend in flood depth, duration, and area is observed from the early (2020s) to the end (2080s) of the century for both scenarios. The difference between both RCPs is minimal from the 2020s to 2050s but becomes very pronounced in the 2080s. The depth-duration-area with equal weightage provides better hazard results for the area. Flood risk is assessed using the IPCC AR5 framework incorporating vulnerability and exposure. Some medium-hazard zones fall into high-risk zones due to high exposure and vulnerability to flooding. The areas along the left reach are found more hazard-prone, while the areas on the right side are more risk-prone in the 2080s of RCP8.5. The hazard/risk maps will help policymakers identify priority areas for planning a sustainable flood management strategy. HIGHLIGHTS Flood risk is transferred from transboundary river basins to local administrative levels using a multi-model hydrological-hydrodynamic-statistical modelling system.; High-resolution bias-corrected GCM climate data is used.; IPCC AR5 climate scenarios and risk framework are considered.; Future flood hazard and risks are assessed for Arial Khan River Floodplain for the 2020s, 2050s, and 2080s.; Medium hazard zones might have high flood risk in the future.

Awash River Subbasin is one of the major river flood-prone areas in Ethiopia where the most significant part of the railway section is constructed. There is tendency of this railway line being affected by flooding. The study performed the flood risk analysis and flow variability at some selected drainage structures within Sebeta and Adama Section of this line. The climate and observed flow data were sourced from the National Meteorological Agency of Ethiopia and the Ministry of Water, Irrigation and Energy of Ethiopia respectively, and used for hydrological model parametrization, calibration, and validation. DMC, Linear Regression, and Thiessen Polygon were used for climate data consistency check, filling of missing data, and estimation of areal data respectively. The rainfall-runoff was simulated with an HEC-HMS hydrological model using a 20years (2000 – 2019) rainfall data. The model calibration and validation results using NSE, PBIAS, and R2, were found within the statistically acceptable range for the surface runoff simulation. This study developed Rainfall Intensity – Duration Frequency Curve for the selected catchment as an input for the flood frequency analysis in the model. The coefficient of variance was estimated to select the flood discharge structures with the flow variabilities. The flood risk was assessed by comparing the modeled and the as built designed Q100 (m3/s) extracted from the design documents. About 46% of the drainage structures are found prone to flooding at a T100years. This study recommends the use of the methodological procedure adopted in this study for other section of this line by other researchers.

Floods are among the most devastating natural hazards in the world, causing the largest percentage of deaths and property damage. The impact of floods can be mitigated with an adequate knowledge of the territory, which makes it possible to better organize prevention plans with an appropriate analysis of the risk areas, which allows the management of relief efforts quickly and adequately. This work presents a methodology for mapping and monitoring the areas affected by floods and landslides by remote sensing: the correct representation and full interpretation of the territory matrix are essential for quality and sustainability design. In this paper, we used tools and technology that allow us to analyze and visualize the landscape evolution. The calibration of the method was performed on the events that took place in Calabria, in Southern Italy, on 12 August 2015. The proposed methodology concerned the planning of acquisition flights, the selection and setting of the sensors used, and the processing and post-processing of the data collected through the application of algorithms used for data manipulation and interpretation. The process of recognizing the areas with deposits of debris through the spectral signature was carried out using similarity criteria relating to hyperspectral data. The results obtained recommend the adoption of this methodology to deal with emergencies due to flood events.