Railroad bridges and culverts in the United States are often subject to extreme floods, which have been known to washout sections of track and ultimately lead to derailments. The potential for these events is particularly high in the western U.S. due to the lack of data, inadequate radar coverage, and the high spatial and temporal variability of storm events and terrain. In this work, a hydrologic model is developed that is capable of effectively describing the rainfall-runoff relationship of extreme thunderstorms in arid and semi-arid regions. The model was calibrated and validated using data from ten storms at the semi-arid Walnut Gulch Experimental Watershed. A methodology is also proposed for reducing the amount of raingages required to provide acceptable inputs to the hydrologic model, and also determining the most appropriate placement location for these gages. Results show that the model is capable of reproducing peak discharges, peak timings, and total volumes to within 22.1%, 12 min, and 32.8%, respectively. Results of the gage reduction procedure show that a decrease in the amount of raingages used to drive the model results in a disproportionally smaller decrease in model accuracy. Results also indicate that choosing gages using the minimization of correlation approach that is described herein will lead to an increase in model accuracy as opposed to selecting gages on a random basis.

The aim of this research project was to estimate parameters for the distribution of annual maximum flood levels for the Zambezi River at Katima Mulilo. The estimation of parameters was done by using the maximum likelihood method. The study aimed to explore data of the Zambezi's annual maximum flood heights at Katima Mulilo by means of fitting the Gumbel, Weibull and the generalized extreme value distributions and evaluated their goodness of fit.

Thesis (M.Eng. (Hons.)) -- University of Western Sydney, 2008. / A thesis submitted towards the degree of Master of Engineering (Honours) in the University of Western Sydney, College of Health and Science, School of Engineering. Includes bibliographical references.

The diploma thesis on "A Proposal to Optimize the Distribution Network of Water Level Gauging Stations in South Bohemian Region? deals with the distribution network of gauging stations of a category ?A?, ?B? and ?C? in the catchment area in South Bohemia. The thesis has been designed as an overview of the current situation of the gauging stations in South Bohemian Region; it is focused on the distribution network of these stations not only in the areas hit with floods. It examines whether these critical places across which the stations have been distributed since 2002 correspond to the requirements of the current flood protection, whether it would not be advisable either to increase or, on contrary, to reduce the number of stations in the exposed river areas. The data processed by Povodí Vltavy, Horní Vltava s.p. Plant, and documents by the ČHMÚ were used for the purposes of this examination. The result of the thesis is the fact that the number of the distributed gauging stations is sufficient as for the needs of flood protection, which has been found out by means of structured interviews with the respective experts. Position of these stations has been incorporated in the flood prevention plans and most of these plans have been designed just on the basis of the distribution network of the gauging stations. The critical locations have been sufficiently mapped and recorded and the flood forecasting and warning service uses the gained, very precious information from these gauging stations. The goal of the thesis was to assess the current distribution network of the gauging stations on the rivers in South Bohemian Region. The current distribution network of the gauging stations on the rivers in South Bohemian Region was studied on the basis of an analysis of the ascertained data and documents. The first goal of the examination was the issue whether the current distribution network and the number of the gauging stations correspond to the needs of protection of citizens, cultural heritage, and property, and whether it would not be advisable to increase the number of these stations. The other goal of the thesis was to optimize the gauging stations with respect to the usefulness and their distribution network, whether the distribution network corresponds to the flood protection. The current distribution network of the gauging stations was analysed by means of a partial method of field research, consulting the expert books, legal regulations and a field research. By analysing these data, I tried to find out in the thesis whether optimisation of the number and the distribution network of the water level gauging stations correspond to the current requirements of the gained data from the respective subject-matter authorities. Upon the results of the analysis of the documents, it was found out that the distribution network and optimization of all gauging stations of all categories - ?A, B, C" - meet the needs of the catchment and requirements to their distribution. Upon the gained information, it was found out that Povodí Vltavy and the operators of the gauging stations have created a very clearly organised network. The hypothesis whether the water level gauging stations are distributed on all of the important rivers in South Bohemian Region was disapproved. The gained information suggests that the gauging stations are distributed on all rivers in South Bohemian Region. The research results have revealed that there is a number of locations in danger of big flooding, however, overflowing at such areas does not put in danger people?s lives, health or property. To conclude, it can be said no matter a society is prepared for flooding as best as possible, the nature, namely water, is an element that is to be respected a lot. This is very important in terms of protection of health, life, cultural heritage and property. The thesis will be offered to the water-management authorities and administrators of the location for further use.

abstract: A model is presented for real-time, river-reservoir operation systems. It epitomizes forward-thinking and efficient approaches to reservoir operations during flooding events. The optimization/simulation includes five major components. The components are a mix of hydrologic and hydraulic modeling, short-term rainfall forecasting, and optimization and reservoir operation models. The optimization/simulation model is designed for ultimate accessibility and efficiency. The optimization model uses the meta-heuristic approach, which has the capability to simultaneously search for multiple optimal solutions. The dynamics of the river are simulated by applying an unsteady flow-routing method. The rainfall-runoff simulation uses the National Weather Service NexRad gridded rainfall data, since it provides critical information regarding real storm events. The short-term rainfall-forecasting model utilizes a stochastic method. The reservoir-operation is simulated by a mass-balance approach. The optimization/simulation model offers more possible optimal solutions by using the Genetic Algorithm approach as opposed to traditional gradient methods that can only compute one optimal solution at a time. The optimization/simulation was developed for the 2010 flood event that occurred in the Cumberland River basin in Nashville, Tennessee. It revealed that the reservoir upstream of Nashville was more contained and that an optimal gate release schedule could have significantly decreased the floodwater levels in downtown Nashville. The model is for demonstrative purposes only but is perfectly suitable for real-world application. / Dissertation/Thesis / Doctoral Dissertation Civil Engineering 2015

This diploma work has been done as a part of the EC funded projects, MUSIC VK1- CT-2000-00058 and SmartDoc IST-2000-28137. The objective was to create an intuitive and easy to use visualization of flood forecasting data provided in the MUSIC project. This visualization is focused on the Visual User Interface and is built on small, reusable components. The visualization, FloodViewer, is small enough to ensure the possibility of distribution via the Internet, yet capable of enabling collaboration possibilities and embedment in electronic documents of the entire visualization. Thus, FloodViewer has been developed in three versions for different purposes. Analysis and report generation (FloodViewer ) Collaborative analysis (FloodViewerNet ) Presentation and documentation (FloodViewerX).

La prévision des crues et des inondations reste aujourd’hui un défi pour anticiper et assurer la sécurité des biens et des personnes. En France, le SCHAPI, qui dépend du MEDDE, assure ce rôle. Les niveaux et les débits d’un cours d’eau dépendent étroitement des interactions à différentes échelles entre les précipitations, les caractéristiques géométriques du cours d’eau et les propriétés topographiques, géologiques et pédologiques du bassin versant. Les modèles hydrauliques, utilisés dans le cadre de la prévision des crues, sont entachés d’incertitudes qu’il est nécessaire de quantifier et de corriger afin de mieux anticiper l’évolution hydrodynamique du cours d’eau en temps réel. L’objectif de ces travaux de thèse est d’améliorer les prévisions de hauteurs d’eau et de débits, sur le bassin de la Marne, issues des modèles hydrauliques utilisés dans le cadre opérationnel de la prévision des crues à partir de méthodes d’assimilation de données. Ces prévisions reposent sur une modélisation mono-dimensionnelle (1D) de l’hydrodynamique du cours d’eau à partir du code hydraulique 1D Mascaret basé sur la résolution des équations de Saint-Venant, enrichie par une méthode d’assimilation de données in situ utilisant un Filtre de Kalman Étendu (EKF). Ce mémoire de thèse s’articule en cinq chapitres, trois dédiés à la recherche et les deux derniers à l’application opérationnelle. Le chapitre 1 présente les données et les outils utilisés pour caractériser le risque inondation dans le cadre de la prévision des crues, ainsi que les modèles hydrauliques Marne Amont Global (MAG) et Marne Moyenne (MM), sujets d’application des méthodes d’assimilation de données développées dans cette étude. Le chapitre 2 est dédié à la méthodologie : il traite des différentes sources d’incertitudes liées à la modélisation hydraulique et présente les approches d’assimilation de données de type EKF appliquées dans cette étude à travers la maquette DAMP pour les réduire. Dans le chapitre 3, cette approche est appliquée aux modèles MAG et MM en mode réanalyse pour un ensemble de crues ayant touché le bassin de la Marne par le passé. Deux publications ont été insérées dans ce chapitre "étude". Dans le chapitre 4, les corrections appliquées dans le chapitre 3, sont validées à partir du rejeu de la crue de 1983 en condition opérationnelle avec le modèle MM. La quantification des incertitudes de prévision et la réalisation de cartes de zones inondées potentielles y sont aussi abordées. L’application de ces méthodes d’assimilation de données pour les modèles MAG et MM en opérationnel au SCHAPI au niveau national et au SPC SAMA au niveau local est présentée dans le chapitre 5. Cette thèse s’inscrit dans un contexte collaboratif où chacun apporte son expertise : la modélisation hydraulique pour le LNHE, les méthodes numériques pour le CERFACS et la prévision opérationnelle pour le SCHAPI. L’ensemble de ces travaux de thèse a permis de démontrer les bénéfices et la complémentarité de l’estimation des paramètres et de l’état hydraulique par assimilation de données sur les hauteurs d’eau et les débits prévus par un modèle hydraulique 1D, ce qui constitue un enjeu d’importance pour l’anticipation du risque hydrologique. Ces méthodes ont été intégrées dans la chaîne opérationnelle de prévision du SCHAPI et du SPC SAMA. / Flood forecasting remains a challenge to anticipate and insure security of people. In France, the SCHAPI, wich depends on the MEDDE, takes this function. Water levels and discharges are highly dependent on interactions at different scales between rainfall, geometric characteristics of rivers and topographic, geological and soil properties of the watershed. Hydraulic models, used in the context of flood forecasting, are tainted by uncertainties which necessist to be quantified and corrected in order to better anticipate flow evolution in real time. The work carried out for this PhD thesis aims to improve water level and discharge forecasts on the Marne watershed, from hydraulic models used in the operational framework of flood forecasting using data assimilation methods. These forecasts come from a mono-dimensional (1D) hydraulic model Mascaret based on the resolution of Saint-Venant equations, improved by data assimilation methods using an Extended Kalman Filter (EKF). This thesis consists of five chapters, three dedicated to research and the two last to the operational application. The first presents data, tools and methods used to characterize the flood risk in the context of flood forecasting, as well as the Marne Amont Global (MAG) and Marne Moyenne (MM) models, subjects of application of data assimilation methods developed in this study. The second chapter covers hydraulic model uncertainties and data assimilation methodology (Kalman filter) applied in this thesis through DAMP in order to reduce them. In the third chapter, this approach is applied to the MAG and MM models for different flood events. In the fourth chapter, the April 1983 flood event allows to validate the corrections applied in the previous chapter for the MM model in an operational context. The uncertainties evaluations and the mapping of potential flooded zones are also reported. The real-time application of these data assimilation methods for MAG and MM models by SCHAPI and SPC SAMA is presented in the fifth chapter. This thesis takes place in a collaborative work where each member brings his own expertise : the hydraulic modeling for LNHE, the numeric methods for the CERFACS and operational forecasting for the SCHAPI. This thesis shows the benefits and complementarity of the evaluation of parameters and hydraulic state using data assimilation on water levels and discharges forcasted by a 1D hydraulic model, which is an important issue for the anticipation of hydrologic risk. These methods have already been integrated to the operational chain of flood forecasting of the SCHAPI and the SPC SAMA.

Floods are the most impactful natural disasters on earth, and reliable flood warning systems are critical for disaster preparation, mitigation, and response. The GEOGloWS ECMWF Streamflow Services (GESS) provide forecasted streamflow throughout the world. While forecasted discharge is essential to flood warning, forecasted inundation extents are required to understand and predict flood impact. In this research, I sought to expand GESS flood warning potential by generating inundation extents from streamflow forecasts. I compared Height Above Nearest Drainage (HAND), a method beneficial for flood mapping on a watershed scale, to a 2D hydrodynamic model, specifically Sedimentation and River Hydraulics – Two Dimension (SRH-2D), a method localized to specific areas of high importance. In three study areas in the Amazon basin, I validated HAND and SRH-2D flood maps against water maps derived from satellite SAR imagery. Specifically, I analyzed what features of an SRH-2D model were required to generate more accurate flood extents than HAND. I also analyzed the practicality of using SRH-2D for forecasting by comparing flood extents generated from simulating a complete forecast hydrograph to flood extents precomputed at predetermined, incremental flowrates. The SRH-2D models outperformed HAND, but their accuracy decreased at flowrates different than those used for calibration, limiting their reliability for forecasting and impact analysis. Based on this study, the key features necessary for a reliable SRH-2D model for forecasting include (1) a high-resolution DEM for an accurate representation of the floodplain, (2) correct representation of channel flow control, and (3) a channel bathymetry approximation and exit boundary rating curve that correctly predict water levels at a range of input flowrates. For forecasting practicality, the precomputed flood extents had accuracies comparable to the complete hydrograph simulations, showing their potential for estimating forecasted inundation extents. Future research should include (1) a more comprehensive analysis using existing SRH-2D models in areas with more bathymetry information and calibration data, (2) further assessment of the reliability of precomputed flood maps for forecasting applications, and (3) quantifying the effect of error in the streamflow forecasts on the accuracy of the resulting flood extents.

京都大学 / 0048 / 新制・課程博士 / 博士(工学) / 甲第18564号 / 工博第3925号 / 新制||工||1603(附属図書館) / 31464 / 京都大学大学院工学研究科社会基盤工学専攻 / (主査)教授 中北 英一, 准教授 KIM Sunmin, 教授 角 哲也 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DFAM

Every year floods are responsible of a significant number of human losses, many of which could be avoided with a broader implementation of flood forecasting systems. Nevertheless, there are still some technological and economic limitations that impede the creation of these systems in many parts of the world. At the core of many flood forecasting systems is a hydrologic model that transforms the weather forecast into a flow forecast. Using real-time modeling for potential floods poses a series of problems: if the model is complex, the computational power required can be significant, and consequently expensive, and if the model is simple enough to run on regular computers in the time allotted, it is likely that the results will not be accurate enough to be useful. I propose the development of a standardized method for using pre-computed scenarios as an alternative to real-time flood modeling. I explain how pre-computing has been used on other realms in the past, and how it is beginning to be implemented in different branches of hydrology, the prediction coastal flooding due to storms or tsunamis being one of the most developed. My research has focused on answering the questions that arise during the design stage of a flood forecasting system not only for rain or snow driven floods, but also by anthropogenic-produced floods. I analyze the number of parameters and their granularity to be used to create the scenarios, the accuracy of the results, different strategies to implement the systems, etc. Finally, I present some test-cases of the application of the method, and assess their results.