Every dam must be capable of safely passing a predetermined flood magnitude. For high-hazard dams, it is a common practice to require that this flood be the Probable Maximum Flood (PMF). The determination of the PMF starts with the determination of the Probable Maximum Precipitation (PMP). We used the generalized estimates of the PMP as outlined in Hydrometeorological Report (HMR) 49. In this study we used the storm event model approach to convert the PMP into PMF. Different synthetic unit hydrograph (SUH) techniques were then used in the conversion process. The Soil Conservation Service (SCS) curve number method was used to estimate the losses, and the U.S. Bureau of Reclamation (USBR) lag time relationship was used as the basis for estimating the time parameters for the different (SUH) methods. The objectives of this study were 1) to evaluate the theoretical and empirical basis for the SUH methods that are commonly used for Utah PMF determinations; 2) to compare the PMF determinations for representative Utah watersheds based on alternative SUH methods using Geographic Information System (GIS) techniques, and to explore the effects of parameter uncertainty ; and 3) to make recommendations for the selection and use of SUH methods for Utah PMF determinations. An interactive PMF modeling system was formulated. The modeling system processes the different databases and estimates the parameters required for HEC 1 model input to produce the PMF hydrograph. Five SUHs were used, tbe SCS, Clark, Snyder, USBR, and the Corps of Engineers (COE) LA valley S-graph. Seven representative Utah high-hazard dam sites were selected and used in the evaluation of the five SUH techniques, focusing on their procedure, practice and applicability, and analytical and empirical evaluations. GIS procedures proved to be a very efficient and flexible means for obtaining rainfall-runoff model inputs. Deviation of the site-specific time-area curve from the default curve in HEC 1 leads to errors in the peak flow estimate. In the absence of suitable events for site-specific development of unit hydrographs, the USBR SUH technique is to be used, but careful consideration should be given to the appropriateness of the use of local storm K, values for Utah local storm PMFs.

Abstract not available

Thesis (M.S.)--Florida State University, 2004. / Advisor: Dr. T.N. Krishnamurti, Florida State University, College of Arts and Sciences, Dept. of Meteorology. Title and description from dissertation home page (viewed June 18, 2004). Title and description from dissertation home page (viewed <date>). Includes bibliographical references.

Tesis para optar al grado de Magíster en Geografía / En esta investigación se estudia la distribución espacial de la amenaza hidrometeorológica, debido a eventos de precipitación máxima entre los 21° y 34° latitud Sur de Chile Continental y su implicancia en los procesos de remoción en masa por flujos en el caso de estudio de las unidades de respuesta de la Cuenca del río Copiapó. Para ello se calcularon los valores máximos probables de precipitación en 24, 48 y 72 horas, analizando las cantidades máximas de precipitación en estaciones pluviométricas con registros desde 1940 hasta el 2015. Se empleó el procedimiento objetivo de análisis estadístico, basado en el ajuste de los datos a leyes de probabilidad, en particular Gumbel Max, y el posterior cálculo de valores máximos para distintos períodos de retorno de 10, 50 y 100 años. Además, se aplicó la metodología de LARA (2007) para determinar la susceptibilidad de remoción por flujos. Los resultados distinguen tres macrozonas, la primera llamada desértica con un umbral de precipitación máxima menor a 30 mm., la segunda llamada desértica intermedia con un umbral de precipitación máxima menor a 60 mm., y una tercera correspondiente al semiárido y mediterráneo con precipitación máxima con un umbral sobre los 60 mm. Teóricamente, se cumple la hipótesis: que las lluvias generadas en períodos estivales en la zona preandina de la Región Metropolitana, su umbral es de 60 mm., no solamente en 24 horas, sino también en 48 y 72 horas; mientras que en los distintos sectores de la ciudad de Antofagasta, su umbral máximo es de 30 mm., en 24 horas, al igual que en 48 y 72 horas. Para el caso de estudio de la Cuenca del río Copiapó, se cumple la hipótesis que el desarrollo de flujos o aluviones se generan con pendientes mayores al rango entre 15° y 25° y se gatilla con un umbral mínimo de precipitación máxima de 22 mm., en 24, 48 y 72 horas.

Presented in this thesis is a case study of two study watersheds located in south central Virginia. For each, a HEC-HMS event-based hydrologic model was constructed to simulate the rainfall-runoff response from the Probable Maximum Storm (PMS), the theoretical worst-case meteorological event that is capable of occurring over a particular region. The primary goal of these simulations was to obtain discharge hydrographs associated with the Probable Maximum Flood (PMF) at key locations in each of the watersheds. These hydrographs were subsequently used to develop flood inundation maps of the study areas and to characterize sediment transport phenomena in the study reaches under severe flooding conditions. To build the hydrologic basin models, ArcHydro, HEC-GeoHMS and ArcGIS were employed to assimilate the substantial amount of input data and to extract the pertinent modeling parameters required for the selected simulation methods. In this, the SCS Loss and Transform Methods, along with the Muskingum Routing Method, were adopted for the HEC-HMS simulations. Once completed, the basin models were calibrated through a comparison of simulated design storm flows to frequency discharge estimates obtained with regional regression techniques and a flood frequency analysis. The models were then used to simulate their respective PMS events, which were developed following recommendations from the Hydrometeorological Branch of the National Weather Service and the U.S. Army Corps of Engineers. Descriptions of each of the study sites, explanations of the modeling theory and development methodologies, and discussions of the modeling results are all detailed within. / Master of Science

A definição de valores máximos de variáveis hidrológicas na engenharia de recursos hídricos atua como ferramenta de extrema importância em vista de inúmeras aplicações práticas que se utilizam desses valores. Neste trabalho é apresentada uma revisão do estado da arte na definição de valores máximos de variáveis hidrológicas (metodologia estatística e determinística). Na metodologia estatística é mostrada uma avaliação conceitual e crítica, na qual é apresentado um exemplo numérico que demonstra as inconsistências ou falhas que caracterizam a necessidade de revisão nos conceitos. Na metodologia determinística é demonstrada as técnicas que definirão os valores da precipitação máxima provável e algumas considerações adicionais quanto à metodologia determinística, principalmente no que se refere às imprecisões dos valores determinados para a precipitação máxima provável/enchente máxima provável. A partir das conclusões sobre ambas as metodologias avaliadas é aplicado uma nova metodologia para determinação de valores máximos de projeto. Essa metodologia, denominada conjugada, resulta da combinação dos procedimentos atualmente usados: metodologia probabilística e determinística. Com o objetivo de caracterizar as importantes contribuições do método conjugado para engenharia, são apresentados alguns estudos de casos que procuram demonstrar a aplicabilidade prática do método e suas vantagens em detrimento aos métodos atuais. A conclusão é que o método conjugado representa um avanço em relação aos métodos atualmente utilizados, uma vez que é consistente com o fenômeno físico e permite atribuir probabilidades às variáveis hidrológicas, resultando em valores de projeto mais realista. / The description of extreme values of hydrological variables in water resources engineering is an extremely importance tool for innumerable practical applications. This work provides a review of statistical and deterministic methods that are used to estimate extreme values of hydrological variables. A critical and conceptual evaluation of statistical methods is presented along with a numerical example that demonstrates the inconsistencies or imperfections of such methods, characterizing the necessity of revisions of these concepts. Deterministic methods to estimate the maximum probable precipitation are also presented and some additional considerations regarding the methodology are discussed, especially those concerned to the imprecise estimates of the maximum probable precipitation/flood. A new methodology to estimate extreme values of hydrologic variables for engineering projects is developed based upon conclusions about the evaluated methodologies. This new methodology is called conjugated, and results from the combination of the currently used statistical and deterministic procedures. In order to characterize the important contributions provided by the conjugated method, some case studies are presented as an attempt to demonstrate its practical applicability as well as its advantages over current methods. The conclusion is that the conjugate method represents an advance with respect to current methods because it is consistent with the physical phenomenon and it allows assigning probabilities to the hydrological variable, resulting in more realistic values to be employed in engineering projects.

A definição de valores máximos de variáveis hidrológicas na engenharia de recursos hídricos atua como ferramenta de extrema importância em vista de inúmeras aplicações práticas que se utilizam desses valores. Neste trabalho é apresentada uma revisão do estado da arte na definição de valores máximos de variáveis hidrológicas (metodologia estatística e determinística). Na metodologia estatística é mostrada uma avaliação conceitual e crítica, na qual é apresentado um exemplo numérico que demonstra as inconsistências ou falhas que caracterizam a necessidade de revisão nos conceitos. Na metodologia determinística é demonstrada as técnicas que definirão os valores da precipitação máxima provável e algumas considerações adicionais quanto à metodologia determinística, principalmente no que se refere às imprecisões dos valores determinados para a precipitação máxima provável/enchente máxima provável. A partir das conclusões sobre ambas as metodologias avaliadas é aplicado uma nova metodologia para determinação de valores máximos de projeto. Essa metodologia, denominada conjugada, resulta da combinação dos procedimentos atualmente usados: metodologia probabilística e determinística. Com o objetivo de caracterizar as importantes contribuições do método conjugado para engenharia, são apresentados alguns estudos de casos que procuram demonstrar a aplicabilidade prática do método e suas vantagens em detrimento aos métodos atuais. A conclusão é que o método conjugado representa um avanço em relação aos métodos atualmente utilizados, uma vez que é consistente com o fenômeno físico e permite atribuir probabilidades às variáveis hidrológicas, resultando em valores de projeto mais realista. / The description of extreme values of hydrological variables in water resources engineering is an extremely importance tool for innumerable practical applications. This work provides a review of statistical and deterministic methods that are used to estimate extreme values of hydrological variables. A critical and conceptual evaluation of statistical methods is presented along with a numerical example that demonstrates the inconsistencies or imperfections of such methods, characterizing the necessity of revisions of these concepts. Deterministic methods to estimate the maximum probable precipitation are also presented and some additional considerations regarding the methodology are discussed, especially those concerned to the imprecise estimates of the maximum probable precipitation/flood. A new methodology to estimate extreme values of hydrologic variables for engineering projects is developed based upon conclusions about the evaluated methodologies. This new methodology is called conjugated, and results from the combination of the currently used statistical and deterministic procedures. In order to characterize the important contributions provided by the conjugated method, some case studies are presented as an attempt to demonstrate its practical applicability as well as its advantages over current methods. The conclusion is that the conjugate method represents an advance with respect to current methods because it is consistent with the physical phenomenon and it allows assigning probabilities to the hydrological variable, resulting in more realistic values to be employed in engineering projects.

Le risque contentieux est une incertitude prévisible. Il peut se définir comme la probabilité de survenance d’une cause contentieuse multipliée par l’ampleur des conséquences attachées à cette survenance. Le risque contentieux pèse d’abord sur le décideur public et les administrés. Son traitement s’effectue en deux phases. La première phase correspond au stade où le risque contentieux est éventuel, c’est-à-dire un risque connu mais non manifesté. Il s’agit alors de prévenir les causes contentieuses en sécurisant la décision publique. Pour y parvenir, la personne publique peut compter sur ses propres moyens ainsi que sur la compétence technique que les tiers peuvent lui apporter. Le risque contentieux devient probable au moment de l’introduction du recours contentieux. Il est alors un risque manifesté mais non encore concrétisé. Le procès est la phase où il convient de gérer le risque contentieux dans le contentieux, notamment par des actions curatives ou palliatives. Ces dernières ont pour objet d’éviter que le risque contentieux se réalise (par l’annulation d’un acte, une condamnation…) ou de limiter les conséquences contentieuses. Et le juge est loin d’être étranger à l’anticipation du risque contentieux. Il y est de plus en plus sensibilisé. Il prévient également les risques contentieux. In fine, ce risque conduit à faire supporter une charge sur la partie perdante et, corrélativement, à rétablir la partie adverse dans ses droits. / Litigation risk is a foreseeable uncertainty. It can be defined as the probability that a cause of action will occur, associated with the extent of the consequences attached to this occurrence. First, litigation risk hangs over policymakers and citizens. It is carried out in two-steps. The first step corresponds to stage when the litigation risk is potential. The risk is known but has not yet actualized. The issue is then to prevent litigation cause by securing public decision-making. To reach this goal, decision makers can, count on their own resources, but also on the expertise of third parties. When a court case is filed, litigation risk becomes probable. That is to say, litigation risk exists but it is not yet materialized. Secondly, the trial is the step in which litigation risk must be handled through remedial or mitigating actions. These actions aim at avoiding the realization of the litigation risk –quashing of an act, condemnation- or containing the consequences of the litigation. Furthermore, judges play a major role in the anticipation of litigation risk: not only are they increasingly aware of it, but also becoming more involved. Ultimately, the risk leads to burdening the losing party, and correlatively, to restoring the rights of the opposing party.

La prédiction de la zygotie à partir du génotype le plus probable en la comparant à la PCR-SSP, n’était pas fiable liée à la possibilité d’avoir d’autres génotypes possibles pour le même phénotype. En effet, la fréquence très proche de l’haplotype R0 et r dans la population tunisienne rend la déduction du génotype le plus probable très aléatoire. Dans un deuxième temps, l’évaluation de la méthode moléculaire la plus convenable à la détermination de la zygotie RHD a été réalisée par comparaison des trois techniques moléculaires (PCR-SSP, PCR-RFLP et Q-PCR) et par l’analyse des résultats discordants par séquençage du gène RHD et des « boîtes Rhésus ». L’analyse de 370 échantillons RH:1 à l'aide de ces trois tests moléculaires a montré que 81,9% des résultats étaient en concordance alors que 18,1% en discordance. L’analyse des cas discordants a montré que notre cohorte se compose de 193 sujets dizygotes et 145 hémizygotes et 32 dont la zygotie reste inconnue. Cette étude a révélé 19 nouveaux polymorphismes des « boîtes Rhésus » et a permis aussi de décrire trois nouveaux allèles RHD: RHD(Trp185Stop), RHD(Ala176Thr) et RHD(Ile342Ile). Cette étude a également mis en valeur l’hétérogénéité des « boîtes Rhésus » et la complexité des allèles RHD en décrivant les nouveaux polymorphismes obtenus, ce qui met en évidence les limites des approches moléculaires de la détermination de la zygotie. La Q-PCR a été la méthode la plus adaptée à la détermination de la zygotie, mais en raison des contraintes économiques locales, la PCR-RFLP pourrait être une alternative malgré l’hétérogénéité des « boîtes Rhésus » et la complexité du gène RHD. / Determination of paternal RHD zygosity can help the clinician to assess the risk of HDN. It was determined initially by both assignment of the most probable genotype and PCR-SSP. The prediction of zygosity based on the most probable genotype was not reliable due to the possibility of other genotypes for the same phenotype. In fact, the frequencies of R0 and r haplotypes in the Tunisian population are approached and make the deduction of the most probable genotype very aleatory. Secondly, the evaluation of the most convenient molecular method for RHD zygosity determination was realized by comparison of three molecular techniques (PCR-SSP, PCR-RFLP and RQ-PCR) and analysis of discordant results by sequencing of the RHD gene and Rhesus boxes. Analysis of 370 RH:1 samples by these three molecular tests showed concordant results in 81.9% and discordant results in 18.1%. Molecular investigations revealed that our cohort consists of 193 dizygous and 145 hemizygous samples and 32 which zygosity remains unknown. This study revealed 19 novel Rhesus boxes polymorphisms, and described 3 novel RHD alleles: RHD(Trp185Stop), RHD(Ala176Thr) and RHD(Ile342Ile). This study also underlined Rhesus boxes heterogeneity and RHD alleles complexity by describing of new polymorphisms which showed the limits of molecular approaches for RHD zygosity determination. RQ-PCR is the most convenient method for first intension paternal RHD zygosity determination in Tunisians. However taking into account local economic constraints PCR-RFLP could be an alternative despite the Rhesus boxes heterogeneity and RHD complexity.

O Estado do Tocantins está localizado entre o domínio do Cerrado e da Floresta Amazônica, o que confere ao mesmo uma diversidade climática importante, especialmente no tocante a ocorrência de chuvas. O conhecimento das chuvas intensas permite o planejamento adequado diante da atuação da precipitação na erosão do solo, inundações em áreas rurais e urbanas, obras hidráulicas, dentre outros. Neste contexto, o objetivo deste estudo foi o mapeamento das chuvas intensas no estado do Tocantins, estruturado em três capítulos com objetivos específicos: (1) com base em 10 estações pluviográficas, determinar constantes de desagregação de chuvas intensas para o Estado do Tocantins; (2) promover o mapeamento de chuvas intensas com durações de 5, 10, 20, 30, 40, 50, 60, 120, 180, 240, 360, 720 e 1440 minutos, associadas com as recorrências de 5, 10, 20, 30, 50, 100, 500 e 1000 anos; e (3) mapear a precipitação máxima provável (PMP) para as durações de 10, 20, 30, 40, 50, 60, 120, 180, 240, 360, 720 e 1440 minutos. Para a modelagem da frequência das chuvas intensas de diferentes durações foi empregada a distribuição de probabilidades de Gumbel para 10 estações pluviográficas. Para o mapeamento das chuvas intensas foram aplicadas séries históricas de 95 postos pluviométricos pertencentes à rede hidrometeorológica da Agência Nacional de Água (ANA), disponibilizadas pelo site Hidroweb, localizados no Tocantins e proximidades, considerando o período de 1983 a 2013, aplicando a geoestatística e avaliando os modelos de semivariograma esférico, exponencial e gaussiano. Para o mapeamento da PMP foi adotado o interpolador inverso do quadrado da distância, tendo sido a sua qualidade avaliada pelo procedimento de validação cruzada, a partir do cálculo da tendência (bias) e do erro médio percentual absoluto (EMPA). Na desagregação das chuvas intensas para o Estado do Tocantins, foram obtidas as seguintes constantes: h10min/h30min = 0,46, h20min/h30min = 0,76, h30min/h1h = 0,68, h40min/h1h = 0,83, h50min/h1h = 0,92, h1h/h24h = 0,61, h2h/h24h = 0,72, h3h/h24h = 0,78, h4h/h24h = 0,82, h6h/h24h = 0,86, h12h/h24h = 0,93. Para o mapeamento das chuvas intensas, o modelo que apresentou o menor erro médio obtido por validação cruzada foi aplicado ao processo de mapeamento por krigagem ordinária, tendo sido observado bom desempenho do modelo esférico para precipitação máxima diária anual e do gaussiano para chuvas desagregadas e associadas a um tempo de retorno. As regiões do Bico do Papagaio (extremo norte), Ilha do Bananal (extremo sudoeste) e noroeste, sob ocorrência de clima Amazônico, respondem pelos valores críticos de chuvas intensas no Estado do Tocantins. Para a maior duração de PMP avaliada (24h), encontraram-se lâminas variando de 410,8 a 768,2 mm, enquanto que, para a menor duração avaliada (10’) as lâminas variaram de 62,5 a 104,6 mm, com padrão de distribuição espacial semelhante às chuvas intensas mapeadas. / The State of Tocantins is located between the area of the Cerrado and the Amazon rainforest, which gives the same an important climatic diversity, especially with regard to rainfall. Knowledge of heavy rainfall allows proper planning considering the action of rainfall on soil erosion, floods in rural and urban areas, waterworks, among others. In this context, the objective of this study was the heavy rainfall mapping in the State of Tocantins, divided into three chapters with specific objectives: (1) based on 10 pluviograph stations, to determine disaggregation constants of heavy rainfall for the State of Tocantins; (2) promote heavy rainfall mapping at durations of 5, 10, 20, 30, 40, 50, 60, 120, 180, 240, 360, 720 to 1440 minutes associated with recurrences of 5, 10, 20, 30, 50, 100, 500 and 1000 years; and (3) to map the probable maximum precipitation for the state of Tocantins based on Hershfield methodology for durations of 10, 20, 30, 40, 50, 60, 120, 180, 240, 360, 720 and 1440 minutes. For modeling the frequency of intense rainfalls of different durations, was used the Gumbel distribution of probabilities for 10 pluviograph stations. For the mapping of heavy rainfall were applied historical series of 95 rain gauge stations belonging to the hydrometeorological network of the National Water Agency (NWA), provided by Hidroweb site, located on the Tocantins and nearby, considering the period 1983-2013, applying geostatistics and evaluating models of semivariogram spherical, exponential and gaussian. For the PMP mapping, was adopted the inverse-square-distance interpolator (ISD), being their quality assessed by cross-validation procedure from the calculation of the trend (bias) and the mean absolute percentage error. In the heavy rainfall disaggregation for the State of Tocantins, the constants were obtained: h10min/h30min = 0.46, h20min/h30min = 0.76, h30min/h1h = 0.68, h40min/h1h = 0.83, h50min/h1h = 0.92, h1h/h24h = 0.61, h2h/h24h = 0.72, h3h/h24h = 0.78, h4h/h24h = 0.82, h6h/h24h = 0.86, h12h/h24h = 0.93. For the heavy rainfall mapping, the model had the lowest average error obtained by cross-validation was applied to mapping by ordinary kriging process, having been observed good performance of the spherical model for maximum annual daily rainfall and gaussian to disaggregate and associated rains a return time. The regions of the Bico do Papagaio (north end), Bananal Island (extreme southwest) and northwest, under occurrence of Amazonian climate account for the critical values of heavy rainfall in the State of Tocantins. For longer duration evaluated PMP (24h), met blades ranging from 410.8 - 768.2 mm, while for the lowest measured duration (10') slides ranged from 62.5 - 104.6 mm with spatial distribution pattern similar to heavy rains mapped.