Due to climate change many regions across the world now have to work with flood risk. The purpose of this master thesis is to understand, from a collaborative governance perspective, how the municipalities City of Gothenburg, City of Mölndal, Kungsbacka municipality, Kungälv municipality and Lerum municipality are working with flood risk management and municipal collaborative planning. The thesis’ aim is to understand how these municipalities are working with each other against flood risk management as well as if they are collaborating with each other in any other aspect within the urban planning context. The thesis is conducted in a qualitative manner and the empirical data was collected through qualitative interviews and qualitative content analysis. The theoretical framework is based on collaborative governance, as well as “municipal collaboration”, “resilience” and “glocal/glocality”. The results show that the municipalities are all working with flood management and integrating that aspect into many aspects of urban planning. It was also presented that the amount of collaborations between the municipalities varies depending on the amount of resources and political interest there is.

<p> Direct policy search (DPS) has been shown to be an efficient method for identifying optimal rules (i.e., policies) for adapting a system in response to changing conditions. This dissertation describes three major advances in the usage of DPS for long-range infrastructure planning, using a specific application domain of flood risk management. We first introduce a new adaptive way to incorporate learning into DPS. The standard approach identifies policies by optimizing their average performance over a large ensemble of future states of the world (SOW). Our approach exploits information gained over time, regarding what kind of SOW is being experienced, to further improve performance via adaptive meta-policies defining how control of the system should switch between policies identified by a standard DPS approach (but trained on different SOWs). We outline the general method and illustrate it using a case study of optimal dike heightening extending the work of Garner and Keller (2018). The meta-policies identified by the adaptive algorithm show Pareto-dominance in two objectives over the standard DPS, with an overall 68% improvement in hypervolume. We also see the improved performance over three grouped SOWs based on future extreme water levels, with the hypervolume improvements of 90%, 46%, and 35% for low, medium, and high water level SOWs respectively. Additionally, we evaluate the degree of improvement achieved by different ways of implementing the algorithm (i.e., different hyperparameter values). This provides guidance for decision makers with different degrees of risk aversion, and computational budgets. </p> <p>Due to simplifying assumptions and limitations of the adaptive DPS model used in the chapter, such as uniform levee design heights, the Surge and Waves Model for Protection Systems (SWaMPS) is presented as a more realistic application of the DPS framework. SWaMPS is a process-based model of surge-based flood risk. This chapter marks the first implementation of DPS using a realistic process-based risk model. The physical process of storm surge and rainfall is simulated independently over multiple reaches, and different frequencies are explored to manage the production system in SWaMPS. The performance of the DPS algorithm is evaluated versus a static intertemporal optimization.</p> <p>The computational burden of evaluating the large ensemble of SOWs to include possible future events in DPS motivates us to apply scenario reduction methods to select representative scenarios that more efficiently span an uncertain parameter space. This allows us to reduce the runtime of the optimization process. We explore a range of data-mining tools, including principal component analysis (PCA) and clustering to reduce the scenarios. We compare the computational efficiency and quality of policies to this optimization problem with reduced ensembles of SOWs.</p>

Tesis por compendio / Flood risk reduction is a global challenge. Society demands higher safety and security levels, including those actions related to flood defence infrastructure protection against natural hazards and manmade threats. Dams and levees, among other flood defence infrastructures, are critical hydraulic infrastructures, aiming at reducing the likelihood that people and property will get flooded, but whose failure would result in consequences for the community downstream, including not only economic damages but also loss of life. There is always a probability associated with infrastructure failure, although in general it might be very low. The purpose of the PhD research, with title "Integrated flood risk management: towards a risk-informed decision making incorporating natural and human-induced hazards", here presented is to propose a framework to enhance integrative flood risk management from a multi-hazard perspective (pluvial flooding, river flooding, dam and levee failure, including man-made threats), addressing current needs for decision making on flood risk reduction and analyzing the complexity of multiple hazards and systems which include multiple components. The thesis is structured in three main parts, including: (i) Part I, a methodology aiming at providing a common framework for identifying and characterizing flood risk due to pluvial flooding, river flooding and dam failure, and incorporate information on loads, system response and consequences into risk models to analyse societal and economic flood risk, (ii) Part II, an approach for quantifying and analyzing risk for complex dam-levee systems, to incorporate information from levee failure into risk models based on the aforementioned methodology, and to analyse societal and economic flood risk, including the potential failure of these infrastructures, and (iii) Part III, a screening tool to characterize the impact of human induced threats on risk due to dam failure or mission disruption. Results from this research have proven that the use of risk models provides a logic and mathematically rigorous framework for compiling information for flood risk characterization and analysis from different natural hazards and flood defence performance. The proposed framework in this thesis and applications aimed at encouraging key actors on flood risk management (infrastructure managers, authorities, emergency action planners, etc.) on the use of QRA, and at demonstrating to what extent QRA can usefully contribute to better understanding risk drivers and inform decisions on how to act to efficiently reduce flood risk. / La reducción del riesgo de inundación es un reto global. La sociedad actual demanda cada vez mayores niveles de seguridad, incluyendo la consecución de acciones vinculadas a la protección de las infraestructuras de defensa frente a inundaciones ante amenazas naturales y antrópicas. Presas y diques, entre otras obras de defensa, son infraestructuras críticas cuyo objetivo es reducir la probabilidad de inundación. Sin embargo, su fallo puede resultar en consecuencias para la comunidad situada aguas abajo, incluyendo no sólo daños económicos sino también pérdida potencial de vidas. Siempre existe una cierta probabilidad asociada al fallo de estas infraestructuras, aunque en general muy baja. El objetivo de la investigación llevada a cabo en la presente tesis doctoral, con título "Integrated flood risk management: towards a risk-informed decision making incorporating natural and human-induced hazards", es proporcionar un marco que fomente la gestión integral del riesgo de inundación desde una perspectiva multi-amenaza, considerando las necesidades actuales en la toma de decisiones para la gestión del riesgo de inundación y analizando la complejidad de sistemas con múltiples componentes, afectados por diferentes amenazas. La tesis se estructura en tres partes principales, incluyendo: (a) Parte I, una metodología para proporcionar un marco común para la identificación y caracterización del riesgo de inundación por inundación pluvial, fluvial y fallo de presas, incorporando información sobre solicitaciones, respuesta del sistema y consecuencias en modelos de riesgo que permiten analizar y evaluar el riesgo social y económico por inundación, (b) Parte II, un método para la cuantificación y análisis del riesgo en sistemas complejos presa-dique, con el objetivo de incorporar información referente al fallo de diques en la metodología propuesta en la Parte I, y analizar el riesgo social y económico por inundación incluyendo el fallo de varias infraestructuras de defensa, y (c) Parte III, una herramienta de cribado que permite caracterizar el impacto de amenazas de origen antrópico en el riesgo asociado al fallo de presas. Los resultados de esta investigación demuestran que el uso de modelos de riesgo proporciona un marco lógico y matemáticamente riguroso para la consideración de toda la información necesaria para la adecuada caracterización y análisis del riesgo de inundación por amenazas naturales y por fallo o mal funcionamiento de obras de defensa. El marco metodológico propuesto y las aplicaciones descritas en esta tesis tienen como objetivo impulsar la aplicación del análisis de riesgo por parte de los actores clave en la gestión del riesgo de inundación (gestores de infraestructuras, autoridades locales, gestores de emergencias, etc.) y demostrar en qué medida estos análisis pueden contribuir a alcanzar un mejor conocimiento de los factores clave que componen el riesgo e informar en la toma de decisiones hacia una reducción del riesgo más eficiente. / La reducció del risc d'inundació és un repte global. La societat actual demana majors nivells de seguretat, incloent-hi la realització d'accions vinculades a la protecció de les infraestructures de defensa enfront del risc d'inundacions afectades per amenaces naturals i antròpiques. Preses i dics fluvials, entre altres obres de defensa, són infraestructures crítiques i tenen l'objectiu de reduir la probabilitat d'inundació però el seu trencament pot resultar en conseqüències en, danys econòmics i també pèrdua potencial de vides. Sempre hi ha una certa probabilitat vinculada al trencament d'aquestes infraestructures, encara que en general molt baixa. L'objectiu de la investigació duta a terme en aquesta tesi doctoral, amb títol "Integrated flood risk management: towards a risk-informed decision making incorporating natural and human-induced hazards", és proporcionar un marc per a fomentar la gestió integral del risc d'inundació des d'una perspectiva multi-amenaça, tenint en compte les necessitats actuals per prendre decisions per a la gestió del risc d'inundació i analitzant sistemes complexes amb múltiples components i afectats per diferents amenaces. La tesi s'estructura en tres parts principals: (a) Part I, una metodologia proposada per a proporcionar un marc comú per a la identificació i caracterització del risc d'inundació per inundació pluvial, fluvial i trencament de preses, incorporant informació de sol¿licitacions, resposta del sistema i conseqüències en models de risc que permeten analitzar el risc social i econòmic per inundació, (b) Part II, un mètode per a la quantificació i anàlisi del risc en sistemes complexes, amb l'objectiu d'incorporar informació referent al trencament de dics fluvials en la metodologia descrita en la Part I, i analitzar el risc social i econòmic pel trencament de diverses infraestructures de defensa, i (c) Part III, una ferramenta de pre-anàlisi per a caracteritzar l'impacte d'amenaces de origen antròpic en el risc associat al trencament de preses. Els resultats de la investigació demostren l'utilitat de l'aplicació de models de risc, proporcionant un marc lògic i matemàticament rigorós per a la consideració de tota la informació necessària per a l'adequada caracterització i anàlisi del risc d'inundació per amenaces naturals i per trencament d'obres de defensa. El marc metodològic i les aplicacions derivades d'aquesta tesi tenen com a objectiu impulsar l'aplicació d'anàlisi de risc quantitatius per part dels actors vinculats a la gestió del risc d'inundació (gestors d'infraestructures, autoritats locals, gestors d'emergències, etc.) i demostrar que poden contribuir a disposar d'un millor coneixement dels factors clau que componen el risc, i per a informar les decisions necessàries per a una reducció del risc més eficient. / Castillo Rodríguez, JT. (2017). Integrated Flood Risk Management: Towards a Risk-Informed Decision Making Incorporating Natural and Human-Induced Hazards [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/82305 / Compendio

Natural disasters such as floods, droughts and storms cause many deaths and a great deal of damage worldwide. Recently, several countries have suffered from an the increased number of floods. This has led government agencies to seek to improve flood risk management by providing historical data obtained from stationary sensor networks to help communities that live in hazardous areas. However, the sensor networks can only help to check specific features (e.g. temperature and pressure), and are unable to contribute significantly to supplying the missing information that is required. In addition to stationary sensors, mobile sensors have also been used to monitor floods since they can provide images and reach distances that are not within the coverage of stationary sensors. By combining these heterogeneous sensors, an initiative called Sensor Web Enablement (SWE) seeks to free these applications from the idiosyncrasies that affect the implementation of these heterogeneous sensors. However, SWE cannot always be applied effectively in a context where sensors are embedded and removed dynamically. This dynamic context makes it a complex task to handle, control, access and discover sensors. In view of this, the aim of this work is to dynamically manage heterogeneous sensors involved in flood risk management in near real-time, by enabling interoperable access to their data and using open and reusable components. To achieve this goal, a service-oriented middleware was designed that contains a common protocol message, a dynamic sensor management component and a repository. This approach was evaluated performed by employing an application that prioritizes geographically social media messages based on sensor data. / Os desastres naturais, como inundações, secas e tempestades causam muitas mortes e danos em todo o mundo. Mais recentemente, alguns países sofreram com o aumento das inundações, comparado com outros tipos de desastres. Para melhor gerenciá-las, agências governamentais têm fornecido dados históricos de redes de sensores estáticas para ajudar comunidades que vivem em áreas de risco. No entanto, tais redes de sensores apenas ajudam a verificar propriedades específicas (por exemplo, temperatura e pressão) e pouco contribuem com a falta de informações presente nesse contexto. Além dos sensores estáticos, sensores móveis também têm sido utilizados para monitorar inundações, uma vez que podem fornecer imagens e alcançar distâncias onde sensores estáticos não funcionam adequadamente. Para combinar esses sensores, deve ser utilizado uma iniciativa chamada Sensor Web Enablement (SWE) que isola as aplicações das idiossíncrasias da implementação desses sensores heterogêneos. Entretanto, a SWE não gerencia completamente contextos em que sensores são inseridos e removidos dinamicamente. Este contexto dinâmico torna complexo o controle, o acesso e a descoberta de novos sensores. Logo, o objetivo deste trabalho é gerenciar dinamicamente e próximo do tempo-real sensores heterogêneos envolvidos na gestão de inundações, permitindo um acesso interoperável para seus dados usando componentes abertos e de re-uso. Para alcançar esse objetivo, um middleware orientado a serviços contendo um protocolo de mensagens comum, um componente de gerenciamento dinâmico de sensores e um repositório foi desenvolvido. A avaliação dessa abordagem foi feita considerando uma aplicação que prioriza geograficamente dados de mídias sociais baseados em dados de sensores.

Die Dissertation befasst sich mit der integrierten Bewirtschaftungsplanung von Flusseinzugsgebieten. Die europäische Wasserrahmenrichtlinie (WRRL, 2000/60/EG) und die europäische Hochwasserrichtlinie (HWRL, 2007/60/EG) setzen dafür neue Maßstäbe, indem beide die Mitgliedsstaaten zur Aufstellung einzugsgebietsbezogener Planungsinstrumente verpflichten. In der Arbeit werden eingangs die wesentlichen Prozesse, theoretischen Modelle und Ansatzpunkte für ein integriertes Management von Flusseinzugsgebieten vorgestellt. Die Anforderungen an Bewirtschaftungspläne und Maßnahmenprogramme der WRRL werden den Vorgaben für die Erstellung der Hochwasserrisikomanagementpläne und ihren planerischen Grundlagen gemäß HWRL gegenübergestellt. Potenzielle Synergien und Konflikte zwischen den Zielen und Maßnahmen werden identifiziert. Der Vergleich der Planungsschritte und -methoden zeigt, dass Abstimmungsbedarf zwischen den Planungsinstrumenten des Flussgebiets- und Hochwasserrisikomanagements für sämtliche Planungsschritte besteht, von der Systemanalyse bis zur Maßnahmenumsetzung. Darauf aufbauend wird ein Konzept für eine integrierte Bewirtschaftungsplanung entwickelt. Das Konzept besteht aus einzelnen fachlich-methodischen Planungsmodulen für jeden Planungsschritt. Sie können im Zusammenhang oder für sich genommen zur Abstimmung zwischen den Plänen des Flussgebiets- und Hochwasserrisikomanagements dienen. Abschließend werden die fachlichen und organisatorischinstitutionellen Potenziale des Konzepts diskutiert und weitergehender Forschungsbedarf aufgezeigt. / The thesis addresses the integrated planning of river basins. For this, the European Water Framework Directive (WFD, 2000/60/EC) and the Floods Directive (FD, 2007/60/EC) are setting new benchmarks by committing its member states to set up river basin-wide management plans. At the beginning of the thesis, the most important processes, theoretical models and options of intervention for integrated river basin management are introduced. The requirements for the river basin management plans and the programmes of measures of the WFD will be contrasted with the specifications for the flood risk management plans according to the FD and their fundamental planning documents. Potential synergies and conflicts between the objectives and measures are identified. The comparison of the planning steps and methods show that all planning steps, from the systems analysis to the implementation of measures, require a coordination of the planning instruments of river basin management and flood risk management. Based on these findings, a concept of integrated river basin management planning is developed. The concept is composed of planning modules for each planning step. For the reconciliation between the plans of river basin management and flood risk management, those planning modules can be used in combination or separately. Finally, the technical and institutional potentials of the concept are discussed. Need for further research is identified.

Natural disasters such as floods, droughts and storms cause many deaths and a great deal of damage worldwide. Recently, several countries have suffered from an the increased number of floods. This has led government agencies to seek to improve flood risk management by providing historical data obtained from stationary sensor networks to help communities that live in hazardous areas. However, the sensor networks can only help to check specific features (e.g. temperature and pressure), and are unable to contribute significantly to supplying the missing information that is required. In addition to stationary sensors, mobile sensors have also been used to monitor floods since they can provide images and reach distances that are not within the coverage of stationary sensors. By combining these heterogeneous sensors, an initiative called Sensor Web Enablement (SWE) seeks to free these applications from the idiosyncrasies that affect the implementation of these heterogeneous sensors. However, SWE cannot always be applied effectively in a context where sensors are embedded and removed dynamically. This dynamic context makes it a complex task to handle, control, access and discover sensors. In view of this, the aim of this work is to dynamically manage heterogeneous sensors involved in flood risk management in near real-time, by enabling interoperable access to their data and using open and reusable components. To achieve this goal, a service-oriented middleware was designed that contains a common protocol message, a dynamic sensor management component and a repository. This approach was evaluated performed by employing an application that prioritizes geographically social media messages based on sensor data. / Os desastres naturais, como inundações, secas e tempestades causam muitas mortes e danos em todo o mundo. Mais recentemente, alguns países sofreram com o aumento das inundações, comparado com outros tipos de desastres. Para melhor gerenciá-las, agências governamentais têm fornecido dados históricos de redes de sensores estáticas para ajudar comunidades que vivem em áreas de risco. No entanto, tais redes de sensores apenas ajudam a verificar propriedades específicas (por exemplo, temperatura e pressão) e pouco contribuem com a falta de informações presente nesse contexto. Além dos sensores estáticos, sensores móveis também têm sido utilizados para monitorar inundações, uma vez que podem fornecer imagens e alcançar distâncias onde sensores estáticos não funcionam adequadamente. Para combinar esses sensores, deve ser utilizado uma iniciativa chamada Sensor Web Enablement (SWE) que isola as aplicações das idiossíncrasias da implementação desses sensores heterogêneos. Entretanto, a SWE não gerencia completamente contextos em que sensores são inseridos e removidos dinamicamente. Este contexto dinâmico torna complexo o controle, o acesso e a descoberta de novos sensores. Logo, o objetivo deste trabalho é gerenciar dinamicamente e próximo do tempo-real sensores heterogêneos envolvidos na gestão de inundações, permitindo um acesso interoperável para seus dados usando componentes abertos e de re-uso. Para alcançar esse objetivo, um middleware orientado a serviços contendo um protocolo de mensagens comum, um componente de gerenciamento dinâmico de sensores e um repositório foi desenvolvido. A avaliação dessa abordagem foi feita considerando uma aplicação que prioriza geograficamente dados de mídias sociais baseados em dados de sensores.

Traditional grey infrastructure in New Orleans, Louisiana has become increasingly less efficient and adaptable to changing flood risks in the face of climate change and increasing development of flood-prone areas. City planners and decision-makers are beginning to use integrated flood risk management as a tool to increase community flood resiliency, however inequalities between communities’ representation still exist. The extent and methods of community participation within the decision-making of flood risk management requires more research. Thus, this study aims to examine methods of community participation within three city plans and to investigate if they are procedurally just for socially vulnerable populations. Based on existing research regarding city planning, this study will attempt to answer the following question: how are socially vulnerable populations being incorporated into the flood risk management decision-making of New Orleans’ city plans? Social vulnerability, in this context, is defined as the attributes of individuals or communities that create challenges in preparation for, protection from, and restoration from flood events.  In-depth content analyses of three New Orleans city plans involving flood risk mitigation were accomplished using coding an grouping related to the study’s research aim. This method was combined with conducting semi-structured interviews of key individuals involved in the analyzed city plans. This study shows the implications of incorporating socially vulnerable populations into community participation within flood risk planning in New Orleans. While it seems that there is an increased use and awareness of community participation methods within flood risk management planning in New Orleans, procedurally just methods and socially vulnerable populations’ engagement are lacking and left unassessed. Further research is needed to establish greater legitimacy of the importance for city government to prevent further marginalization of communities that are unequally engaging with flood risk planning.

Cette thèse doctorale porte sur la gestion des risques d’inondation et des capacités d’adaptation des zones côtières, notamment face au changement climatique. Le contexte actuel est tel que la vulnérabilité face aux aléas d’inondation est amplifiée par les phénomènes du changement climatique et par la forte exposition, des personnes et des biens, en zones à risques. Sous le cadre général du projet européen Theseus ’’Innovative technologies for safer European coasts in a changing climate’’, ce travail de recherche s’est, en particulier, appuyé sur une étude de cas en France : l’estuaire de la Gironde.L’objectif de ce travail est de proposer un cadre alternatif d’adaptation de la gestion des inondations, à l’égard des incertitudes liées au contexte climatique.Dans cet objectif, cette recherche est partie d’une étude d’exploration, des perceptions locales vis-à-vis des inondations, pour analyser ensuite la gestion actuelle, sous forme de combinaison entre mesures structurelles et non structurelles.La publication d’articles scientifiques, contenus dans ce rapport, cristallise l’essentiel des résultats obtenus et illustre la démarche itérative de progression, entre le recueil des données du terrain et l’analyse des concepts théoriques.Cette thèse doctorale a abouti à la proposition d’un cadre opérationnel de renforcement de la résilience appliqué à l’aménagement du territoire, aux systèmes d’alerte, aux plans d’évacuation, aux plans de continuité de fonctionnement, aux programmes d’assurance et à la gestion du post-trauma. / This PhD thesis deals with the flood risk management and the adaptation capacities of coastal areas, in regard of the climate change.Currently, the flood hazard vulnerability is aggravated by both the climate change phenomenon and the huge exposure, of people and assets, in risk areas. In the general framework of Theseus european project, this research work has particularly focused on the Gironde estuary, in France, as a case study.The aim of this work is to provide an alternative framework of adaptation for the flood risk management, in regard of the climate change related uncertainties.In this order, our research is initiated by anexploratory study , of the local perception toward the flood hazard, followed by the analysis of the current flood risk management, as a set of structural and nonstructural measures.The published papers, included in this report, summarize our results and illustrate our iterative approach between the field data collection and the theoretical concepts analysis.This thesis research has led to put forward an operationnal framework to enhance the resilience applied to land use planning, warning systems and evacuation plans, business recovery plans, insurance programs and post trauma management.

Can one society’s flood risk perception and management strategy impact the neighbouring society? This study applies a socio-hydrological model to four ideal types of society living along the same river. These societies have various rationalities and risk perceptions: risk-controlling, risk-monitoring, risk- neglecting and risk-downplaying. Combined with a hydraulic model of the river, this study explores the human-flood interactions and how the four societies can influence each other. The results show that the society that adopts soft-measures experiences the lowest flood loss; the society that neglects flood risks suffers from much higher flood losses. Dynamics, including the levee effect and adaptation effect, can also be observed. The society that builds levees to alter the hydrological regime causes the flood stage to be higher than it would have been without levees, indirectly increasing flood loss for the neighbouring societies. A more sustainable flood risk management strategy calls for broader considerations than the conventional method. / Skulle ett samhälles uppfattning om översvämningsrisk och förvaltningsstrategi påverka det närliggande samhället? Denna studie tillämpar en sociohydrologisk modell på fyra idealtyper av samhälle som lever längs samma flod. Dessa samhällen har olika rationaliteter och riskuppfattningar: riskkontroll, riskövervakning, riskförsummelse och risknedsättande. I kombination med en hydraulisk modell av floden, utforskar denna studie interaktionen mellan människa och översvämning och hur de fyra samhällena kan påverka varandra. Resultaten visar att det samhälle som vidtar mjuka åtgärder upplever lägst översvämningsförlust; det samhälle som försummar översvämningsrisker lider av mycket högre översvämningsförluster. Dynamik, inklusive valleffekten och anpassningseffekten, kan också observeras. Det samhälle som bygger vallar för att förändra den hydrologiska regimen gör att översvämningsstadiet blir högre än det skulle ha varit utan vallar, vilket indirekt ökar översvämningsförlusterna för de närliggande samhällena. En mer hållbar strategi för hantering av översvämningsrisk kräver bredare överväganden än den konventionella metoden.

Thesis (MScEng)--Stellenbosch University, 2012. / ENGLISH ABSTRACT: The devastating effects floods have on both social and economic level make effective flood risk management an essential part of rural and urban development. A major part of effective flood risk management is the application of reliable design flood estimation methods. Research over the years has illustrated that current design flood estimation methods as a norm show large discrepancies which can mainly be attributed to the fact that these methods are outdated (Smithers, 2007). The research presented focused on the evaluation and updating of the Midgley and Pitman (MIPI) and the Catchment Parameter (CAPA or McPherson) empirical design flood estimation methods. The evaluation was done by means of comparing design floods estimated by each method with more reliable probabilistic design floods derived from historical flow records. Flow gauging stations were selected as drainage data points based on the availability of flow data and available catchment characteristics. A selection criterion was developed resulting in 53 gauging stations. The Log Normal (LN) and Log Pearson Type III (LP III) distributions were used to derive the probabilistic floods for each gauging station. The flow gauging stations were used to delineate catchments and to quantify catchment characteristics using Geographic Information Systems (GIS) software and their associated applications. The two methods were approximated by means derived formulas instead of evaluating and updating the two methods from first principles. This was done as a result of the constraints brought about by both time and the attainment of the relevant literature. The formulae were derived by means of plotting method inputs and resulted in graphs, fitting a trendline through the points and deriving a formula best describing the trendline. The derived formulae and the catchment characteristics were used to estimate the design floods for each method. A comparison was then done between the design flood results of the two methods and the probabilistic design floods. The results of these comparisons were used to derive correction factors which could potentially increase the reliability of the two methods used to estimate design floods. The effectiveness of any updating would be the degree (or level) in which the reliability of a method could be increased. It was proven that the correction factors did decrease the difference between the „assumed and more reliable probabilistic design floods‟ and the methods‟ estimates. However, the increase in reliability of the methods through the use of the recommended correction factors is questionable due to factors such as the reliability of the flow data as well as the methods which had to be used to derive the correction factors. / AFRIKAANSE OPSOMMING: Die verwoestende gevolge van vloede op beide ekonomiese en sosiale gebiede beklemtoon die belangrikheid van effektiewe vloed risiko bestuur vir ontwikellings doeleindes. „n Baie belangrikke gedeelte van effektiewe vloed risiko bestuur is die gebruik van betroubare ontwerp vloed metodes. Navorsing oor die laaste paar jaar het die tekortkominge van die metodes beklemtoon, wat meestal toegeskryf kan word aan die metodes wat verouderd is. Die navorsing het gefokus op die evaluering en moontlike opdatering van die Midley en Pitman (MIPI) en die “Catchment Parameter” (CAPA of McPherson) empiriese ontwerp vloed metodes. Die evaluering het geskied deur middel van die vergelyking van die ontwerp vloed soos bereken deur die twee metodes en die aanvaarde, meer betroubare probabilistiese ontwerp vloede, bepaal deur middel van statistiese ontledings. Vloei meetstasies is gekies as data-punte omrede die beskikbaarheid van vloei data en beskikbare opvanggebied eienskappe. „n Seleksie kriteruim is ontwikkel waaruit 53 meetstasies gekies is. Die Log Normale (LN) en Log Pearson Tipe III (LP III) verspreidings is verder gebruik om die probabilistiese ontwerp vloede te bereken vir elke meetstasie. Die posisie van die meetstasies is ook verder gebruik om opvanggebiede te definieer en opvanggebied eienskappe te bereken. Geografiese inligtingstelsels (GIS) is vir die doel gebruik inplaas van die oorspronlik hand metodes. Die twee metodes is benader deur die gebruik van afgeleide formules inplaas van „n eerste beginsel benadering. Dit is gedoen as gevolg van die beperkings wat teweeggebring is deur beide tyd en die beskikbaarheid van die relevante litratuur wat handel oor die ontwikkeling van die twee metodes. Die formules is verkry deur middel van die plot van beide insette en resultate in grafieke, die passing van tendenslyne en die afleiding van formules wat die tendenslyne die beste beskryf. Die afgeleide formules saam met die opvanggebied eienskappe is toe verder gebruik om die ontwerp vloede van elke meet stasie te bepaal, vir beide metodes. The resultate van die twee metodes is toe vergelyk met die probabilistiese ontwerp vloede. Die resultate van hierdie vergelyking is verder gebruik om korreksie faktore af te lei wat moontlik die betroubaarheid van die twee metodes kon verhoog. Die doeltreffendheid van enige opdatering sal die mate wees waarin die betroubaarheid van n metode verhoog kan word. Gedurende die verhandeling is dit bewys dat die korreksie faktore wel n vermindering teweebring in die verskil tussen die ontwerp vloede van die aanvaarde meer betroubare probabilistiese ontwerp vloede van beide metodes. Die toename in betroubaarheid van die metodes deur die gebruik van die voorgestelde korreksie faktore is egter bevraagteken as gevolg van faktore soos die betroubaarheid van die vloei data self asook die metodologie wat gevolg is om die korreksie faktore af te lei.