With urbanisation continuing to encroach upon flood plains, the constant replacement of permeable land with impermeable surfaces and with the changes in global climate, the need for improved flood modelling is ever more apparent. A wide range of methods exist that simulate surface flow; most commonly in one-dimensional (1D) or twodimensional (2D), and more recently on smaller scales in three-dimensional (3D) models. In urban flood modelling, 2D models are often the preferred choice as they can simulate surface flow more accurately than their 1D model counterparts; they are, however, more computationally demanding and thereby usually require greater simulation time. With the vast amount of information used in flood modelling, generalisation techniques are often employed to reduce the computational load within a simulation. The objective of this thesis is to improve 2D flood modelling in urban environments by introducing a new and novel approach of representing fine scale building features within coarse grids. This is achieved by creating an automated approach that data-mines key features such as buildings and represents their effects numerically within a multiple layer grid format. This new approach is tested in comparison to two other, already established generalising techniques which are single layer based. The effectiveness of each model is assessed by its ability to accurately represent surface flow at different grid resolutions and how each copes with varying building orientations and distributions within the test datasets. The performance of each generalising approach is determined therefore by its accuracy in relation to the fine scale model and the difference in the computational time required complete the simulation. Finally the multilayered methodology is applied to a real case scenario to test its applicability further. Overall it revealed, as predicted, that the multilayered approach enables far greater accuracies at routing surface flow within coarse grids whilst still greatly reducing computational time. As a further benefit in urban flood modelling, this thesis shows that using a multilayered data format it is possible to simulate the influence of features that have a grid resolution finer than the initial terrain topology data, thus enabling, for example, the routing of surface water through alleyways between buildings that have a width less than one meter.

The research presented in this Thesis aims at defining the strengths and weaknesses of an Improved 1D/1D model when compared with a more accurate 1D/2D model. Although both coupled-models (sewer/surface) solve the St.\ Venant equations in both layers, the latter uses a higher approximation (2D two-dimensional) on the surface layer. Consequently, the 1D/1D model is computationally more efficient when compared to the 1D/2D model, however there is some compromise with the overall accuracy. The hypothesis is that "The inundation extent of urban flooding can be reproduced by 1D/1D models in good agreement with the 1D/2D models if the results are kept within certain limits of resolution and under certain conditions". The Thesis starts by investigating ways of improving an existing 1D/1D model to rival the more accurate 1D/2D model. Parts of the 1D/1D model code are changed and new algorithms and routines implemented. An innovative GIS tool translates the 1D output-results into 2D flood-inundation-maps enabling a thorough comparison between the two models. The methodology assures the set-up of two equivalent models, which includes a novel algorithm for calibrating the 1D/1D model vs.\ the 1D/2D model results. Developments are tested in two distinctly different case studies of areas prone to flooding. The conclusion is that the 1D/1D model is able to simulate flooding in good agreement with the 1D/2D model; however, it is found that features such as topography, density of the urbanised areas and rainfall distribution may affect the agreement between both models. The work presented herein is a step forward in understanding the modelling capabilities of the analysed coupled-models, and to some extent may be extrapolated to other models. Research is growing in urban flooding and this work may well prove to be a strong foundation basis for future research.

This thesis provides a basic framework for probabilistic real-time urban flood forecasting based on data of varying degree of quality and quantity. The framework was developed based on precipitation data from two case study areas:Aarhus Denmark and Castries St. Lucia. Many practitioners have acknowledged that a combination of structural and non-structural measures are required to reduce the effects of flooding on urban environments, but the general dearth of the desired data and models makes the development of a flood forecasting system seem unattainable. Needless to say, high resolution data and models are not always achievable and it may be necessary to override accuracy in order to reduce flood risk in urban areas and focus on estimating and communicating the uncertainty in the available resource. Thus, in order to develop a pertinent framework, both primary and secondary data sources were used to discover the current practices and to identify relevant data sources. Results from an online survey revealed that we currently have the resources to make a flood forecast and also pointed to potential open source quantitative precipitation forecast (QPF) which is the single most important component in order to make a flood forecast. The design of a flood forecasting system entails the consideration of several factors, thus the framework provides an overview of the considerations and provides a description of the proposed methods that apply specifically to each component. In particular, this thesis focuses extensively on the verification of QPF and QPE from NWP weather radar and highlights a method for estimating the uncertainty in the QPF from NWP models based on a retrospective comparison of observed and forecasted rainfall in the form of probability distributions. The results from the application of the uncertainty model suggest that the rainfall forecasts has a large contribution to the uncertainty in the flood forecast and applying a method which bias corrects and estimates confidence levels in the forecast looks promising for real-time flood forecasting. This work also describes a method used to generate rainfall ensembles based on a catalogue of observed rain events at suitable temporal scales. Results from model calibration and validation highlights the invaluable potential in using images extracted from social network sites for model calibration and validation. This framework provides innovative possibilities for real-time urban flood forecasting.

Este tese objetiva analisar sistemas complexos de drenagem urbana visando definir uma técnica de dimensionamento de obras de reservação. Nesta pesquisa, sistemas complexos de drenagem urbana são aqueles compostos por diversos reservatórios de detenção, distribuídos numa rede de canais formada por vários trechos. Este tipo de sistema é típico em megacidades. O dimensionamento das obras de reservação em redes complexas possui uma série de condicionantes, ou seja, ele é função de diversas variáveis, muitas delas de caráter aleatório. A principal delas é a chuva de projeto. Esta tese desenvolve uma técnica conjunta de simulação e de cenarização de chuvas com defasagem no tempo e no espaço para tratar a questão da variabilidade da precipitação de projeto. Do ponto de vista hidráulico, existem outras condicionantes para dimensionamento, dependendo do tipo de reservação adotada. Basicamente existem dois tipos de reservatórios para controle de cheias em cidades, os reservatórios on-line e os reservatórios off-line, cada um apresenta características próprias de desempenho que devem ser consideradas quando o sistema é dimensionado. Esta tese apresenta uma técnica de dimensionamento iterativa que permite compor um conjunto de reservatórios (on-line ou off-line) que atendem ao grau de proteção requerido para uma bacia urbana. Os métodos foram avaliados em bacias hipotéticas típicas de grandes cidades. Desse modo, uma série de variáveis foi contemplada, na tentativa de generalizar o método proposto. Os resultados mostraram a importância da cenarização da chuva de projeto. É praticamente inviável trabalhar hoje com as premissas clássicas para definir a chuva de projeto, a cenarização permite avaliar o desempenho do sistema segundo diferentes condições hidrológicas. Finalmente, ressalta-se que esta tese apresenta um enfoque novo de dimensionamento e que certamente irá requerer novas investigações e aperfeiçoamentos. Ela procura trazer à discussão a implementação de novos paradigmas para desenvolvimento de projetos no campo da drenagem urbana em grandes cidades. / This thesis aims to analyze urban drainage complex systems in order to define a technique for the design of detention ponds structures. In this study, Urban Drainage Complex Systems are those composed of several detention ponds, distributed in a network of channels formed by various reaches. This type of system is typical in megacities. The design of the reservation structures in complex networks has a number of constraints, in other words, it is a function of several variables, many of them are randomness. The main one is the design rainfall. This thesis develops a joint technical of simulation and the design rainfall scenario generation delayed in time and space to deal with the variability of design precipitation. From the hydrological point of view, there are other constraints for scaling, depending on the type of reservation adopted. There are basically two types of detention ponds for flood control in cities, on-line detention and off-line detention, each performance has its own characteristics that must be considered when the system is designed. This thesis presents an iterative design technique for composing a set of detention ponds (on-line or off-line) that satisfy the degree of protection required for an urban watershed. The methods were evaluated in hypothetical basins typical of large cities. Thus, a series of variables was included in an attempt to generalize the proposed method. The results showed the importance of design rainfall scenario generation. It is practically impossible to work today with the classical assumptions to define the design rainfall; the scenario generation allows evaluating system performance under different hydrological conditions. Finally, we emphasize that this thesis presents a new approach to sizing and it certainly will require further research and improvements. It seeks to bring the discussion to implementation of new paradigms for development projects in the field of urban drainage in large cities.

Este tese objetiva analisar sistemas complexos de drenagem urbana visando definir uma técnica de dimensionamento de obras de reservação. Nesta pesquisa, sistemas complexos de drenagem urbana são aqueles compostos por diversos reservatórios de detenção, distribuídos numa rede de canais formada por vários trechos. Este tipo de sistema é típico em megacidades. O dimensionamento das obras de reservação em redes complexas possui uma série de condicionantes, ou seja, ele é função de diversas variáveis, muitas delas de caráter aleatório. A principal delas é a chuva de projeto. Esta tese desenvolve uma técnica conjunta de simulação e de cenarização de chuvas com defasagem no tempo e no espaço para tratar a questão da variabilidade da precipitação de projeto. Do ponto de vista hidráulico, existem outras condicionantes para dimensionamento, dependendo do tipo de reservação adotada. Basicamente existem dois tipos de reservatórios para controle de cheias em cidades, os reservatórios on-line e os reservatórios off-line, cada um apresenta características próprias de desempenho que devem ser consideradas quando o sistema é dimensionado. Esta tese apresenta uma técnica de dimensionamento iterativa que permite compor um conjunto de reservatórios (on-line ou off-line) que atendem ao grau de proteção requerido para uma bacia urbana. Os métodos foram avaliados em bacias hipotéticas típicas de grandes cidades. Desse modo, uma série de variáveis foi contemplada, na tentativa de generalizar o método proposto. Os resultados mostraram a importância da cenarização da chuva de projeto. É praticamente inviável trabalhar hoje com as premissas clássicas para definir a chuva de projeto, a cenarização permite avaliar o desempenho do sistema segundo diferentes condições hidrológicas. Finalmente, ressalta-se que esta tese apresenta um enfoque novo de dimensionamento e que certamente irá requerer novas investigações e aperfeiçoamentos. Ela procura trazer à discussão a implementação de novos paradigmas para desenvolvimento de projetos no campo da drenagem urbana em grandes cidades. / This thesis aims to analyze urban drainage complex systems in order to define a technique for the design of detention ponds structures. In this study, Urban Drainage Complex Systems are those composed of several detention ponds, distributed in a network of channels formed by various reaches. This type of system is typical in megacities. The design of the reservation structures in complex networks has a number of constraints, in other words, it is a function of several variables, many of them are randomness. The main one is the design rainfall. This thesis develops a joint technical of simulation and the design rainfall scenario generation delayed in time and space to deal with the variability of design precipitation. From the hydrological point of view, there are other constraints for scaling, depending on the type of reservation adopted. There are basically two types of detention ponds for flood control in cities, on-line detention and off-line detention, each performance has its own characteristics that must be considered when the system is designed. This thesis presents an iterative design technique for composing a set of detention ponds (on-line or off-line) that satisfy the degree of protection required for an urban watershed. The methods were evaluated in hypothetical basins typical of large cities. Thus, a series of variables was included in an attempt to generalize the proposed method. The results showed the importance of design rainfall scenario generation. It is practically impossible to work today with the classical assumptions to define the design rainfall; the scenario generation allows evaluating system performance under different hydrological conditions. Finally, we emphasize that this thesis presents a new approach to sizing and it certainly will require further research and improvements. It seeks to bring the discussion to implementation of new paradigms for development projects in the field of urban drainage in large cities.

Kyoto University (京都大学) / 0048 / 新制・課程博士 / 博士(工学) / 甲第15354号 / 工博第3233号 / 新制||工||1486(附属図書館) / 27832 / 京都大学大学院工学研究科都市社会工学専攻 / (主査)教授 岡田 憲夫, 教授 戸田 圭一, 教授 多々納 裕一 / 学位規則第4条第1項該当

As the global climate gets warmer, local extreme weather becomes more frequent, and it becomes more and more difficult to accurately predict the occurrence of extreme rainfall. At the same time, the threat and destructiveness of stormwater weather to urban water systems and cities are also increasing due to the continuous advancement of urbanization, the continuous gathering of urban population and the increasingly obvious urban heat island effect.Since it was first proposed, resilience thinking has become a very important idea in urban planning and research. With the continuous development of resilience thinking, its concept and connotation are also constantly improved and developed. It has developed from a single state of resilience at the beginning to cover all aspects of social, economic and ecological issues.This research aims to find the resilience level of the urban water system of Rotterdam, and find some typical cases of Rotterdam’s experience for other cities to learn. Based on the resilience thinking, this study takes Rotterdam as an example to comprehensively evaluate the resilience of the urban water system under stormwater disaster and urban flood and waterlogging. The first part of this thesis first introduces the urban water system, resilience thinking and other concept which this thesis use. In the second part, this thesis mainly introduced the specific analytical method and analytical framework, namely ASPIRE model. The third part will combine the analysis model with the example of Rotterdam, and comprehensively analyze the stormwater adaptive resilience of the urban water system. In the fourth part of this thesis, three engineering examples of Rotterdam which worthy of promotion and learning are introduced and summarized in detail. The last part of this thesis is the discussion and conclusion. Through this study, it is found that the urban water system of Rotterdam has high stormwater adaptive resilience and Rotterdam has many successful experiences which can be learned by other cities.

yes / Urban flooding is a combined product of the climate and watershed geomorphology. River system is one of the vital components of watershed geomorphology. The geomorphic characteristics of rivers have important effect on the formation of flooding. However, there have been few attempts so far to investigate the relationship between flooding frequency, the probability of flooding, and the geomorphological complexity of river system. Such relationship is essential in order to predict likely responses of flooding frequency to the large-scale changes in the complexity of the river networks induced by accelerating urbanization around river. In this study we investigate the correlation between geomorphological characteristics of river system and the probability of flooding. Hangzhou city in China, which has suffered severe flooding, is chosen as a case study to evaluate this correlation and to investigate the impact of changes of drainage networks morphology on the local flooding. The fractal dimension, which is used to quantitatively assess geomorphological complexity of river network, is calculated by using box-counting method based on fractal geometry for eight sub river networks in Hangzhou. A model based on the correlation of flooding frequency and fractal dimension is established. The model is applied to investigate the effect of the rapid urbanization induced changes of river geomorphology on the local flood frequency in two typical regions in Hangzhou. The results show that the flood frequency/events increases with the decrease of fractal dimension of the river network, indicating that the geomorphologic complexity of river network has an important effect on flooding. This research has great referential value for future flood quantitative investigation and provides new method for urban flood control and river system protection. / Key Scientific and Technical Project of Water Conservancy of Zhejiang Province (Grant No: RB1401)

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