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[pt] Atrelado à densa ocupação dessas áreas, identifica-se que parte de suas feições naturalmente protetoras da linha de costa são recorrentemente suprimidas da paisagem, dando lugar a obras de engenharia rígidas que passam a ocupar o perfil dinâmico das praias. Com isso, em casos de eventos de tempestades, as praias tornam-se susceptíveis a ação das ondas, bem como a população que habita a beira mar. Nesse sentido, o presente trabalho tem como objetivo caracterizar sazonalmente o comportamento morfodinâmico e sedimentar do arco praial localizado entre o Leblon e Arpoador e sua suspectibilidade aos efeitos das ressacas, fornecendo subsídios para a gestão do litoral. Para a obtenção dos dados foram aquisitados 32 perfis topográficos de praia entre 2018-2021, com o método das balizas de Emery; análises nas areias das praias (granulometria e morfoscopia); análises morfoscópicas; cálculos do volume emerso dos sedimentos e levantamento de alertas de ressacas emitidos pela Marinha do Brasil e demais veículos midiáticos. As extremidades do arco praial (pontos LB01 e AR01) apresentaram maior variabilidade morfológica e na largura da praia variação da largura da praia.; o ponto LB02 (próximo ao canal de Jardim de Alah) apresenta-se como o mais susceptível às ondas de tempestades; e o ponto IP01 (localizado no meio do arco), é considerado o mais estável devido à presença de ilhas em sua frente. Os sedimentos emersos do arco praial exibiram uma sazonalidade marcada por acúmulo no verão e perda subsequente dos mesmos no inverno. O papel das ondas é essencial na dinâmica do arco praial, com incidência predomiante de Sudoeste (tempestade) e Sudeste (tempo bom), o que possibilita a formação de correntes de deriva litorânea importantes na distribuição Leste-Oeste rotacional de sedimentos no arco praial. Conclui-se que o arco praial apresenta certo equilibrio dinâmico, uma vez que os perfis topográficos mostram grande variabilidade de largura e tal dinâmica pode ser corroborada pela relação de ganha e perda do volume de sedimentos do arco. A areia média é predominante porém percebe-se uma distinta distribuição dos grãos no arco praial: observou areias médias a grossas na porção oeste (Leblon) e areias médias a finas na porção leste (Arpoador). A distribuição sedimentar se mostra diferente também em termos de grau de arredondamento (no pós-praia os grãos são subarredondados e na face de praia são subangulares), seleção do grão e maturidade. / [en] Linked to the dense occupation of these areas, it is identified that part of its features that naturally protect the coastline are recurrently suppressed from the landscape, giving way to rigid engineering works that begin to occupy the dynamic profile of the beaches. With that, in cases of storm events, the beaches become susceptible to wave action, as well as the population that inhabits the seaside. In this sense, the present work aims to seasonally characterize the morphodynamic and sedimentary behavior of the coast located between Leblon and Arpoador and its susceptibility to the effects of storm surges, providing subsidies for the management of the coast. To obtain the data, 32 topographic beach profiles were acquired between 2018- 2021, using the Emery method; beach sand analyzes (granulometry and morphoscopy); morphoscopic analysis; calculations of the emerged volume of sediments and survey of storm surge alerts issued by the Brazilian Navy and other media outlets. The ends of the beach (points LB01 and AR01) showed greater morphological variability and variation in beach width in beach width.; point LB02 (close to the Jardim de Alah channel) is the most susceptible to storm waves; and point IP01 (located in the middle of the arc), is considered the most stable due to the presence of islands in front of it. Emerged sediments from the coast exhibited a seasonality marked by accumulation in summer and subsequent loss in winter. The role of waves is essential in the dynamics of the beach arc, with predominant incidence from the Southwest (storm) and Southeast (clear weather), which enables the formation of longshore drift currents that are important in the rotational East-West distribution of sediments in the beach arc. It is concluded that the Leblon-Arpoador coast presents a certain dynamic balance, since the topographic profiles show great variability in width and such dynamics can be corroborated by the relationship between gain and loss in the volume of sediments in the arch. Medium sand is predominant, but a distinct distribution of grains can be seen in the coast: medium to coarse sand was observed in the western portion (Leblon) and medium to fine sand in the eastern portion (Arpoador). The sedimentary distribution is also different in terms of degree of roundness (in the backshore the grains are subrounded and in the beach face they are subangular), grain selection and maturity.

<p>Hourly archived rainfall records are separated into individual rainfall events with</p> <p>an Inter-Event Time Denition. Individual storms are characterized by their depth,</p> <p>duration, and peak intensity. Severe events are selected from among the events for</p> <p>a given station. A lower limit, or threshold depth is used to make this selection,</p> <p>and an upper duration limit is established. A small number of events per year are</p> <p>left, which have relatively high depth and average intensity appropriate to small</p> <p>to medium catchment responses. The Generalized Pareto Distributions are tted</p> <p>to the storm depth data, and a bounded probability distribution is tted to storm</p> <p>duration. Peak storm intensity is bounded by continuity imposed by storm depth</p> <p>and duration. These physical limits are used to develop an index measure of peak</p> <p>storm intensity, called intensity peak factor, bounded on (0; 1), and tted to the Beta</p> <p>distribution. The joint probability relationship among storm variables is established,</p> <p>combining increasing storm depth, increasing intensity peak factor, with decreasing</p> <p>storm duration as being the best description of increasing rainstorm severity. The</p> <p>joint probability of all three variables can be modelled with a bivariate copula of</p> <p>the marginal distributions of duration and intensity peak factor, combined simply</p> <p>with the marginal distribution of storm depth. The parameters of the marginal</p> <p>distributions of storm variables, and the frequency of occurrence of threshold-excess</p> <p>events are used to assess possible shifts in their values as a function of time and</p> <p>temperature, in order to evaluate potential climate change eects for several stations.</p> <p>Example applications of the joint probability of storm variables are provided that</p> <p>illustrate the need to apply the methods developed.</p> <p>The overall contributions of this research combine applications of existing probabilistic</p> <p>tools, with unique characterizations of rainstorm variables. Relationships</p> <p>between these variables are examined to produce a new description of storm severity,</p> <p>and to begin the assessment of the eects of climate change upon severe rainstorm</p> <p>events.</p> <p>i</p> / Doctor of Philosophy (PhD)