Vulnerability occurs at the intersection of natural geophysical forces and human settlement decisions. When humans decide to place themselves and their homes in harm’s way and disinvest in mitigation measures, vulnerability ensues. Human decisions have and continue to play a large role in furthering vulnerability, especially in coastal communities. With roughly 50 percent of the United States’ population currently located on the coast and with rapid development only projected to continue, coastal communities will be faced with a future of exacerbated flood events that will result in increased surface runoff, flooding, and economic losses. This report focuses on better understanding how the build environment exacerbates coastal vulnerability. This research involves the creation of a spatial vulnerability index to flood risk for Galveston County which uncovers the degree with which the built environment is exposed to flood risk and how this vulnerability can be responded to in a manner that builds coastal resiliency. / text

Flood-control reservoirs experience water level fluctuations that control survival of their biota. I explored diverse but related aspects of water-level management. Three frameworks were indentified for directing rule curve (i.e., daily targets for water levels) changes in flood-control reservoirs managed by the U.S. Army Corps of Engineers (USACE), with differing scopes and requirements. Framework choice depends on the reservoir’s primary authorization and magnitude of the contemplated change. Changes without congressional approval must be based on flood risk. Quantile regression was used to model a maximum water level with a user-specified level of risk. Because actions that request changes to water levels from natural resource professionals should have a sound ecological basis, I analyzed the relationships between water level fluctuations and vegetation in reservoirs. Remote sensing methods were used to calculate a greenness index from vegetation in the reservoir based on 14 years of satellite imagery and water levels.

Cemeteries have a lot of different values, both to people but also to society. Besides from being a burial place where survivors can go to be close to their deceased, they can also function as restorative places or cultural and historical places. This study’s aim is to investigate how future changes in the climate may potentially have impacts on cemeteries in Sweden in forms of flooding and to make a rough estimation of how many cemeteries that would be affected by this. This study will also investigate how many individuals that would be affected by this. In order to investigate this an overlay analysis was done in a Geographical Information System (GIS). The results showed that there are some cemeteries that would potentially have 10% or more of the total area flooded, given the scenarios in this study. It also shows that there could potentially be a lot of individuals that would be affected, in different ways.

<p>Översvämningar är ett stort problem på flera håll i Sverige och klimatförändringarna väntas förvärra situationen i vissa delar av landet. I syfte att strukturera arbetet med översvämningsrisker togs översvämningsdirektivet (2007:60:EG) fram i EU år 2007. Direktivet genomförs som förordning (SFS 2009:956) i Sverige och denna infördes i svensk lagstiftning den 26 november 2009. Enligt förordningen om översvämningsrisker har Myndigheten för Samhällsskydd och Beredskap en viktig roll då de ska utföra den preliminära bedömningen av översvämningsrisker, bl.a. genom framtagande av kartor som redovisar översvämningshotade områden. Vattenmyndigheter och länsstyrelser ska ansvara för framtagandet av kartor med risker inom de översvämningshotade områdena, samt riskhanteringsplaner för att minska de möjliga ogynnsamma följderna.</p><p>För att underlätta arbetet med översvämningsrisker behöver samtliga aktörer ha en bra och aktuell kunskapsgrund. Ett av syftena med detta examensarbete var därför att ta fram en kunskapsöversikt inom området. Denna översikt togs fram genom en litteraturstudie och den redovisar bl.a. information om EU-projekt med översvämningsanknytning samt fakta om olika höjdmodeller och översvämningskarteringar.</p><p>En annan del av examensarbetet syftade till att besvara ett antal uppställda frågeställningar, som bl.a. behandlade hur god medvetenheten, samverkan och krisberedskapen är hos myndigheter i Sverige. För att avgöra ovanstående utfördes en intervjustudie med ett antal kommuner och länsstyrelser, samt med Vattenmyndigheten för Västerhavet. Resultatet visade att samtliga tillfrågade aktörer hade god medvetenhet om översvämningsrisker. En inträffad översvämning medför en utökad prioritering av arbetet med översvämningsrisker och även en större angelägenhet att samverka med andra aktörer om dessa risker. Krisberedskapen var även den mest uttalad hos de som drabbats av översvämningar och visade sig ha en nära koppling till god medvetenhet och samverkan.</p><p>Slutligen skulle examensarbetet ge svar på vilka riskobjekt som bör bedömas i översvämningshotade områden. För att optimera arbetet med skadereducerande och förebyggande åtgärder bör objekten inom ett översvämningshotat område prioriteras efter sannolikheten att de drabbas, samt hur stora konsekvenserna skulle bli om detta hände. I examensarbetet besvarades denna frågeställning med hjälp av litteraturstudier. Där fokuserades på vilka konsekvenser som kan uppkomma av en översvämning. Ett förslag på riskobjekt togs fram och en översiktlig indelning av hur objekten skulle kunna prioriteras i en akut situation utfördes. Dessutom sammanställdes var data för kartframställning kan hittas för respektive riskobjekt.</p> / <p>Flooding is a major problem in many parts of Sweden and climate changes are expected to aggravate the situation in some parts of the country. In order to structure the work on flood risks the flood directive (2007:60:EG) was initiated by the EU in 2007. The directive is implemented as a regulation in Sweden (SFS 2009:956) and this regulation was introduced in Swedish legislation in November 26th 2009. According to this regulation, the Swedish Civil Contingencies Agency (Myndigheten för Samhällsskydd och Beredskap) plays an important role as they will perform the preliminary assessment of flood risks, including the production of maps of floodthreatened areas. Water authorities and other county administrative boards will be responsible for the preparation of maps of risks within the flood-threatened areas and risk management plans in order to reduce the potential adverse consequences.</p><p>To facilitate the process of flood risks all the players need to have a good and current knowledge. Therefore, one aim of this thesis was to develop a knowledge overview in the field. This overview was prepared by a literature review and includes information on flood-related EU projects, and facts about different elevation models and flood mapping. Another part of the thesis aimed to answer a number of set questions, such as: how good is the awareness, collaboration and emergency preparedness among the Swedish authorities. To determine this an interview study with a number of municipalities and county administration boards, and the Water Authority for the Western Sea (Vattenmyndigheten för Västerhavet) was carried out. The results showed that all the approached players had good awareness of flood risks. A past flood involves results in an expanded priority to work on flood risks and also a major concern to interact with other players on those risks. Crisis preparedness was also most expressed among those affected by floods and was found to have close links to good awareness and interaction.</p><p>Finally, the thesis aimed to answer the risk items that should be considered in floodthreatened areas. To optimize the process of damage reduction and prevention, the objects in a flood-threatened area should be prioritized by the likelihood that the objects will be affected, and also by how big the impact would be if this happened. In the thesis, this question was answered by means of literature studies which focused on the consequences that may arise from a flood. A proposal on the risk properties was developed and an overall breakdown of how the items could be given priority in an emergency was carried out. In addition, it was compiled where data for mapping can be found for each risk item.</p>

Översvämningar är ett stort problem på flera håll i Sverige och klimatförändringarna väntas förvärra situationen i vissa delar av landet. I syfte att strukturera arbetet med översvämningsrisker togs översvämningsdirektivet (2007:60:EG) fram i EU år 2007. Direktivet genomförs som förordning (SFS 2009:956) i Sverige och denna infördes i svensk lagstiftning den 26 november 2009. Enligt förordningen om översvämningsrisker har Myndigheten för Samhällsskydd och Beredskap en viktig roll då de ska utföra den preliminära bedömningen av översvämningsrisker, bl.a. genom framtagande av kartor som redovisar översvämningshotade områden. Vattenmyndigheter och länsstyrelser ska ansvara för framtagandet av kartor med risker inom de översvämningshotade områdena, samt riskhanteringsplaner för att minska de möjliga ogynnsamma följderna. För att underlätta arbetet med översvämningsrisker behöver samtliga aktörer ha en bra och aktuell kunskapsgrund. Ett av syftena med detta examensarbete var därför att ta fram en kunskapsöversikt inom området. Denna översikt togs fram genom en litteraturstudie och den redovisar bl.a. information om EU-projekt med översvämningsanknytning samt fakta om olika höjdmodeller och översvämningskarteringar. En annan del av examensarbetet syftade till att besvara ett antal uppställda frågeställningar, som bl.a. behandlade hur god medvetenheten, samverkan och krisberedskapen är hos myndigheter i Sverige. För att avgöra ovanstående utfördes en intervjustudie med ett antal kommuner och länsstyrelser, samt med Vattenmyndigheten för Västerhavet. Resultatet visade att samtliga tillfrågade aktörer hade god medvetenhet om översvämningsrisker. En inträffad översvämning medför en utökad prioritering av arbetet med översvämningsrisker och även en större angelägenhet att samverka med andra aktörer om dessa risker. Krisberedskapen var även den mest uttalad hos de som drabbats av översvämningar och visade sig ha en nära koppling till god medvetenhet och samverkan. Slutligen skulle examensarbetet ge svar på vilka riskobjekt som bör bedömas i översvämningshotade områden. För att optimera arbetet med skadereducerande och förebyggande åtgärder bör objekten inom ett översvämningshotat område prioriteras efter sannolikheten att de drabbas, samt hur stora konsekvenserna skulle bli om detta hände. I examensarbetet besvarades denna frågeställning med hjälp av litteraturstudier. Där fokuserades på vilka konsekvenser som kan uppkomma av en översvämning. Ett förslag på riskobjekt togs fram och en översiktlig indelning av hur objekten skulle kunna prioriteras i en akut situation utfördes. Dessutom sammanställdes var data för kartframställning kan hittas för respektive riskobjekt. / Flooding is a major problem in many parts of Sweden and climate changes are expected to aggravate the situation in some parts of the country. In order to structure the work on flood risks the flood directive (2007:60:EG) was initiated by the EU in 2007. The directive is implemented as a regulation in Sweden (SFS 2009:956) and this regulation was introduced in Swedish legislation in November 26th 2009. According to this regulation, the Swedish Civil Contingencies Agency (Myndigheten för Samhällsskydd och Beredskap) plays an important role as they will perform the preliminary assessment of flood risks, including the production of maps of floodthreatened areas. Water authorities and other county administrative boards will be responsible for the preparation of maps of risks within the flood-threatened areas and risk management plans in order to reduce the potential adverse consequences. To facilitate the process of flood risks all the players need to have a good and current knowledge. Therefore, one aim of this thesis was to develop a knowledge overview in the field. This overview was prepared by a literature review and includes information on flood-related EU projects, and facts about different elevation models and flood mapping. Another part of the thesis aimed to answer a number of set questions, such as: how good is the awareness, collaboration and emergency preparedness among the Swedish authorities. To determine this an interview study with a number of municipalities and county administration boards, and the Water Authority for the Western Sea (Vattenmyndigheten för Västerhavet) was carried out. The results showed that all the approached players had good awareness of flood risks. A past flood involves results in an expanded priority to work on flood risks and also a major concern to interact with other players on those risks. Crisis preparedness was also most expressed among those affected by floods and was found to have close links to good awareness and interaction. Finally, the thesis aimed to answer the risk items that should be considered in floodthreatened areas. To optimize the process of damage reduction and prevention, the objects in a flood-threatened area should be prioritized by the likelihood that the objects will be affected, and also by how big the impact would be if this happened. In the thesis, this question was answered by means of literature studies which focused on the consequences that may arise from a flood. A proposal on the risk properties was developed and an overall breakdown of how the items could be given priority in an emergency was carried out. In addition, it was compiled where data for mapping can be found for each risk item.

Over recent years, community resilience has been increasing in popularity as a topic for detailed study. During that time, academic researchers have been working to untangle the complex network of social relationships that define the concept. In parallel, some institutions have set the achievement of enhanced community resilience as a policy goal. This research has sought to assist in both areas: first, by contributing to the academic debate and second, to build a clearer understanding of how institutions can tailor policies to ensure success in their goal of enhancing community resilience. A case study approach was adopted for the research, centring on three communities in the Teign Estuary of South Devon (Newton Abbot, Teignmouth and Shaldon). All three communities were vulnerable to tidal flooding and links between the communities and institutions responsible for managing flood risk (FRM framework) were analysed. In the analysis, a specific form of social capital was studied: social capital derived from community-institution links (CISC). CISC was found to be effective in revealing links with the greatest potential to enhance the resilience of communities against flood risks. To assess resilience at the individual and community level, a maturity based model was used. The assessment found disparities between how resilience matures at the community level compared to the individual level. Specifically, resilience maturity in communities was revealed as a less linear process. As such, the case study communities were able to exhibit traits associated with low resilience maturity at the same time as exhibiting traits associated with high resilience maturity. This research concluded that the UK FRM policy framework was robust, aligning well with academic theory. However, the FRM system was revealed as being dominated by expert elites. These elites are mainly public sector based and were judged to be stifling the engagement of the private sector at the local level. To enhance their resilience, this study determined that communities need to investment in CISC, but that investment must not just be targeted at public sector FRM institutions alone, it also needs to target private sector FRM institutions.

Storm sewer systems play a very important role in urban areas. The design of a storm sewer system should be based on an appropriate level of preventing flooding. This thesis focuses on issues relevant to decision-making in storm sewer network design considering flood risk. Uncertainty analysis is often required in an integrated approach to a comprehensive assessment of flood risk. The first part of this thesis discusses the understanding and representation of uncertainty in general setting. It also develops methods for propagating uncertainty through a model under different situations when uncertainties are represented by various mathematical languages. The decision-making process for storm sewer network design considering flood risk is explored in this thesis. The pipe sizes and slopes of the network are determined for the design. Due to the uncertain character of the flood risk, the decision made is not unique but depends on the decision maker’s attitude towards risk. A flood risk based storm sewer network design method incorporating a multiple-objective optimization and a “choice” process is developed with different design criteria. The storm sewer network design considering flood risk can also be formed as a single-objective optimization provided that the decision criterion is given a priori. A framework for this approach with a single objective optimization is developed. The GA is adapted as the optimizer. The flood risk is evaluated with different methods either under several design storms or using sampling method. A method for generating samples represented by correlated variables is introduced. It is adapted from a literature method providing that the marginal distributions of variables as well as the correlations between them are known. The group method is developed aiming to facilitate the generation of correlated samples of large sizes. The method is successfully applied to the generation of rainfall event samples and the samples are used for storm sewer network design where the flood risk is evaluated with rainfall event samples.

Coastal management accounting for shoreline erosion and coastal flooding requires information about various physical processes that take place over a range of temporal and spatial scales. Field measurements provide information on the past and current coastal environment and statistical tools are used to determine extreme conditions that can lead to damage. However, in a changing climate, these conditions cease to be statistically stationary, making predictions problematic. To assess future conditions, a set of scenarios for greenhouse gas emissions has been defined to project impacts on global oceanographic conditions and sea level rise. This thesis estimates the effect of these global projections on coastal processes off the North Norfolk coast of the UK. A model system is set up to downscale global conditions on to nearshore conditions (wave climate, water level and beach profile), which influence coastal stability and coastal flood risk. The system is based on coupling numerical models for different temporal and spatial scales. The area contains large tidal sandbanks and shore-connected sand ridges. The downscaling procedure accounts for interactions that take place on the upper part of the continental shelf where these large-scale seabed features affect wave propagation, tidal flows and sediment transport. The modelling system is then validated against historical data and then used to compute long-term inshore hydrodynamic characteristics and sediment transport resulting from future projections of climate change and sea level rise. This enables an assessment of extreme inshore wave heights, overtopping discharge rates and their occurrence at a sea defence through extreme joint probability analysis. This modelling assumes a fixed seabed. However, the system includes a sub model for the release of sediment from the cliff erosion, which provides a source of sediment for the maintenance of the offshore sandbanks. The link between the cliff and the sandbanks is demonstrated by computing the residual sediment transport. The model system is also used to assess the impact of offshore sand extraction on coastline erosion. Finally, the system is used to analyse an overtopping and flood inundation event at Walcott in 2007 enabling uncertainties in the predictions to be assessed.

Probabilistic risk assessment (PRA) has been used in various engineering and technological fields to assist regulatory agencies, and decision-makers to assess and reduce the risks inherent in complex systems. PRA allows decision-makers to make risk-informed choices rather than simply relying on traditional deterministic flood analyses (e.g., a Probable Maximum Flood) and therefore supports good engineering design practice. Type and quantity of available data is often a key factor in PRA at an early stage for determining the best methodology. However, implementation of PRA becomes difficult and challenging since probability distributions need to be derived to describe the variable states. Flood protection is one of the rare fields in civil engineering where probability is extensively used to describe uncertainty and where the concept of failure risk is explicitly part of the design. The concept of return period is taught in all civil engineering classes throughout the world, and most cities in the developed world have developed flood risk maps where the limits of the 50-year or 100-year flood are shown. While this approach is useful, it has several limitations: • It is based on a single flow value while all flow ranges contribute to the risk; • It is not linked to the actual economic damage of floods; • So far, flood risk maps only account for river water levels. It has been demonstrated that intense rainfall causes significant property damages in West Africa. This study aimed to explore the possibility of developing and implementing a probabilistic flood risk estimation framework where all flow ranges are accounted for: 1) The probability of flood occurrence and the probabilistic distribution of hydraulic parameters, and 2) The probability of damages are spatially calculated in order for the decision-makers to take optimal adaptation decisions (e.g., flood protection dike design, recommendations for new buildings, etc.). In this study the challenges of inferring the probability distribution of different physical flood parameters in a context of sparse data, of linking their parameters to flood damages, and finally the translation of the estimation risk into decision were explored. The effect of the choice of the one-dimensional (1-D) or two-dimensional (2-D) hydraulic models on the estimated flood risk and ultimately on the adaptation decisions was investigated. A first case study on the city of Niamey (Niger, West Africa), was performed using readily available data and 1-D and 2-D HEC-RAS (Hydrologic Engineering Center-River Analysis System) models. Adaptation options to flood risk in Niamey area were examined by looking at two main variables: a) Buildings’ material (CAS: Informal constructions – a mixture of sundried clay and straw, also known as Banco, BAN: Mud walls, DUR: Concrete walls, and SDU: Mud walls covered by mortar); and b) Dike height within a scenario-based framework, where numerical modelling was undertaken to quantify the inundated area. The 1-D and 2-D hydraulic models, HEC-RAS, were tested on a 160 km reach of the Niger River. Using the numerical modelling, water levels within the inundated areas have been identified. The extent of residential areas as well as exposed assets (polygons and building material) associated with each scenario have been evaluated. 1000 probabilistic flood maps were generated and considered in the estimation of the total loss. Benefits and costs of different adaptation options were then compared for residential land-use class in order to implement flood risk maps in the city of Niamey. Results show the individual as well as the combined impact of the two abovementioned variables in flood risk estimation in Niamey region. Dike heights ranged from 180.5 m to 184 m, at a 0.5 m interval, and buildings’ material were considered to be of 0% to 100% of each type, respectively. The results enable decision-makers as well as the regulators to have a quantitative tool for choosing the best preventive measures to alleviate the adverse impacts arising from flood. Also, because of the lack of detailed information on the exposed infrastructure elements in the study area, a feasible yet fast and precise method of extracting buildings from high-resolution aerial images was investigated using an Artificial Intelligence (AI) method – Deep Learning (DL). The applied deep learning method showed promising results with high accuracy rate for the area of interest in this study and was able to successfully identify two introduced classes of Building and Background (non-building). The findings contend that although the proposed structural adaptation options, as a resisting to environment approach, are applied to the area of interest and considered to be technically feasible, other non-structural measures, which have long-term effect of risk mitigation, should be taken into consideration, especially for highly hazard-prone areas. The results of this study would significantly help in loss estimation to the buildings due to the yearly floods in the region of interest, Niamey, Niger. However, since the buildings are of various type of material, having an accurate building database has a great importance in assessing the expected level of damage in the inundated areas, especially to the critical buildings (hospitals, schools, research labs, etc.) in the area.

Floods are one of the most costly natural hazards worldwide, affecting millions of people every year. Flood risk management is of global concern, and a deeper understanding of dynamic flood risk development is needed. Currently,vulnerability and exposure are often assumed to be constant in quantitative flood risk assessments, which does not reflect patterns observed in real life. In fact, flood protection measures on individual and community level can induce changes in both vulnerability and exposure, as well as alter river and floodplain hydraulics. The human-flood system is complex, incorporating two-way interactions between both subsystems. To build up these dynamics from the bottom up with a focus on the role of the individual, an agent-based model was combined with a hydraulic model. It was shown that this coupled model is capable of replicating levee and adaptation effects which are commonly knownto occur in the context of river floods and flood protection measures. Moreover,the new modeling approach can explicitly simulate the spatial distribution of flood risk which allowed for an analysis of conflicting interests in urban and rural areas. Here, model outcomes suggest that a shift of flood risk from high-value urban to lower-value rural areas can reduce system-wide flood losses. However, decreasing flood awareness in the city will push population growth rates, and discontent in rural areas might nally induce a shift of higher floodrisk back to the urban area. In the end, one low-probability high-intensity event might cause a disastrous outcome.