This application aims to identify a possible correlation between the reflectivity factor signal RADAR Weather Radar System of Alagoas (SIRMAL), with the flow of the Rio Mundaú, data obtained fromthe Hydrological Station National Water Agency (ANA) in BoaFortuna, Rio Largo, Alagoas. What is required is a remote monitoring and continuous rate of flow, at one point the river basin Mundaú in order to predict possible flood waves. The floods in the river Mundaú are recurrent, having brought great losses in material resources and human lives for decades, their monitoring is of fundamental importance for better planning and management of these resources. For this we constructed a computer code in object-oriented language, Object Pascal. The program reads the image in jpeg format, generated and provided by SIRMAL on his Internet site, spatially integrates all the values of reflectivity of the microwave pulse on the watershed, determining the volume and then precipitated considered high rainfall area on the Watershed River Mundaú. This value is associated with the reflective state of the basin, at a given time, indicates the amount of precipitated water in the basin for a given period. The high rainfall is related to precipitation over the basin and consequently the flow in river. To verify the correlation with the flow, were chosen five months, the period from 2004 to 2006, when the flow measured at the farm Good Fortune, showed abrupt changes and sought similar variations in rainfall height, measured from the image processing radar. For the months of January 2004, December 2005 and September 2006, we obtained a correlation exceeding 70% between the reflectivity factor and the flow. From the daily analysis of the height and flow rate determined to be a qualitative correlation. This was obtained from the flow data, derived from stories of the season series, obtained in the HIDROWEB ANA rainfall and the height obtained with the method. The correlation was promising but not conclusive. Through the analysis it was demonstrated that the sensitivity of variations in height, indicating up to 24 hours to raise the level of flow to 60% of cases. / O presente trabalho tem como objetivo identificar uma possível correlação entre o fator de refletividade do sinal do RADAR do Sistema de Radar Meteorológico de Alagoas (SIRMAL), com a vazão do Rio Mundaú, obtida a partir de dados da Estação Hidrológica da Agência Nacional de Águas (ANA), na Fazenda Boa Fortuna, Município de Rio Largo, Alagoas. O que se pretende é um monitoramento remoto e contínuo do nível de vazão, em um ponto da bacia hidrográfica do rio Mundaú, com o intuito de prever possíveis ondas de cheias. As enchentes no rio Mundaú são recorrentes, tendo trazido grandes prejuízos em recursos materiais e em vidas humanas ao longo de décadas; o seu monitoramento é de importância fundamental para o melhor planejamento e gerenciamento desses recursos. Para isso foi construído um código de computador, na linguagem orientada a objeto, OBJECT PASCAL. O programa lê a imagem, em formato jpeg, gerada e disponibilizada pelo SIRMAL em seu sítio da Internet, integra espacialmente todos os valores de refletividade do pulso de microondas sobre a bacia, determinando volume precipitado e posteriormente a altura pluviométrica considerada sobre área da Bacia Hidrográfica do rio Mundaú. Este valor está associado ao estado reflexivo da bacia, em um dado momento e indica a quantidade de água precipitada na bacia para um determinado período. A altura pluviométrica está relacionada à precipitação sobre a bacia e em conseqüência à vazão no rio. Para a verificação da correlação com a vazão, foram escolhidos cinco meses, o período de 2004 a 2006, em que a vazão medida na Fazenda Boa Fortuna apresentou variações bruscas, e se procurou variações semelhantes na altura pluviométrica, aferidas a partir do processamento da imagem do radar. Para os meses de janeiro de 2004, dezembro de 2005 e setembro de 2006, obteve-se uma correlação superior a 70% entre o fator de refletividade e a vazão. A partir da análise diária da altura e da vazão determinou-se uma correlação qualitativa. Esta foi obtida a partir dos dados da vazão, retirados das séries histórias da estação, obtidas no sistema HidroWeb da ANA, e a altura pluviométrica obtida a partir dos dados do radar com o método. A correlação se mostrou promissora, porém, não conclusiva. Através da análise foi demonstrado que a sensibilidade das variações na altura, indicando em até 24 horas a elevação do nível de vazão para 60% dos casos estudados.

Cette thèse s’intéresse à la variabilité de la relation mass-diamètre (m(D)) des hydrométéores en phase glace présents dans les systèmes convectif de moyenne échelle (MCS). Elle s’appuie sur une base de données acquise pour 4 types de MCS différents durant 4 campagnes de mesure aéroportée : (i) MCS de la mousson Africaine (Continent ; MT2010), (ii) MCS de l’océan Indien (MT2011), (iii) MCS de la Méditerranée (côtes ; HyMeX), (iv) MCS de la mousson Nord-Australienne (côtes ; HAIC-HIWC). La relation m(D) est calculée à partir de l’analyse combinée des images des hydrométéores enregistrées par les sondes optiques et les facteurs de réflectivité mesurés à l’aide d’un radar Doppler embarqués sur le même avion de recherche. Il est d’usage que la relation m(D) des hydrométéores soit représentée par une loi puissance (avec un pré-facteur et un exposant), qui doit être contrainte par des informations supplémentaires sur les hydrométéores. Une étude théorique sur les formes des hydrométéores à l’aide de simulations en 3 dimensions dans lesquelles les hydrométéores sont orientés aléatoirement et projeté sur un plan, permet de contraindre l’exposant β de la relation m(D) en fonction de l’exposant σ de la relation surface-diamètre (S(D)). La relation S(D) est aussi représentée par une loi puissance, et elle peut-être calculée pour une population d’images d’hydrométéores enregistrés par les sondes optiques. La variabilité de l’exposant est finalement calculée à partir de la variabilité de l’exposant σ déduis des images des hydrométéores. Ensuite le pré-facteur α est calculé à partir de simulations des facteurs de réflectivité, de sorte que les facteurs de réflectivité simulés soient égaux aux facteurs de réflectivité mesurés par le radar nuage le long de la trajectoire de l’avion dans les MCS. Des profils moyens en fonction de la température sont calculés pour les coefficients de la relation m(D), les distributions en tailles des hydrométéores et les contenus massiques de glace dans les MCS (CWC). Les profils moyens pour les quatre types de MCS sont différents les uns des autres. Pour les quatre types de MCS, il est montré que les variations des coefficients de la relation m(D) sont corrélées avec les variations de la température. Four types de paramétrisations de la relation m(D) sont calculées depuis l’analyses des variations des coefficients de la relation m(D). Le bénéfice apporté par l’utilisation de relation m(D) non constante contrairement à l’utilisation de relation m(D) avec α et β constant, est démontré en étudiant l’impact de toutes les paramétrisations de la relation m(D) sur le calcul des relations Z-CWC et Z-CWC-T. / This study focuses on the variability of mass-diameter relationships (m(D)) and shape of ice hydrometeors in Mesoscale Convective Systems (MCS). It bases on data base which were recorded during four airborne measurement campaigns: (i) African monsoon’s MCS (continent; MT2010), (ii) Indian Ocean’s MCS (MT2011), (iii) Mediterranean’s MCS (costs; HyMeX), (iv) North-Australian monsoon’s MCS (costs; HAIC-HIWC). m(D) of ice hydrometeors are derived from a combined analysis of particle images from 2D-array probes and associated reflectivity factors measured with a Doppler cloud radar on the same research aircraft. Usually, m(D) is formulated as a power law (with one pre-factor and one exponent) that need to be constrained from complementary information on hydrometeors. A theoretical study of numerous hydrometeor shapes simulated in 3D and arbitrarily projected on a 2D plan allowed to constrain the exponent β of the m(D) relationship from the exponent σ of the surface-diameter S(D) relationship, which is likewise written as a power law. Since S(D) always can be determined for real data from 2D optical array probes or other particle imagers, the evolution of the m(D) exponent can be calculated. After that, the pre-factor α of m(D) is constrained from theoretical simulations of the radar reflectivity factor matching the measured reflectivity factor along the aircraft trajectory. Mean profiles of m(D) coefficients, particles size distributions and Condensed Water Content (CWC) are calculated in functions of the temperature, and are different for each type of MCS. For the four types of MCS, it is shown that the variability of m(D) coefficients is correlated with the variability of the temperature. Four types of m(D) parametrisations are calculated since the analysis of the variability of the m(D) coefficients. The significant benefit of using variable m(D) relations instead of a single m(D) relationship is demonstrated from the impact of all these m(D) relations on Z-CWC and Z-CWC-T fitted parametrisations.