Degallier N.,IRD Montpellier |
Servain J.,IRD Montpellier |
Lucio P.S.,IRD Montpellier |
Lucio P.S.,Federal University of Rio Grande do Norte |
And 4 more authors.
Journal of Vector Ecology | Year: 2012
It is generally assumed that the daily probability of survival of mosquitoes is independent of age. To test this assumption we have conducted a three-year experimental fieldwork study (2005-2007) at Fortaleza-CE in Brazil, determining daily survival rates of the dengue vector Aedes aegypti (L.). Survival rates of adult Ae. aegypti may be age-dependent and the statistical analysis is a sensitive approach for comparing patterns of mosquito survival. The mosquito survival data were better fit by a Weibull survival function than by the more traditionally used Gompertz or logistic survival functions. Gompertz, Weibull, or logistic survival functions often fit the survival, and the tails of the survival curves usually appear to fall between the values predicted by the three functions. We corroborate that the mortality of Ae. aegypti in semi-natural conditions may no more be considered as a constant phenomenon during the life of adult mosquitoes but varies according to the age and environmental conditions under a tropical climate. This study estimates the variability in the survival rate of Ae. aegypti and environmental factors that are related to such variability. The statistical analysis shows that the fitting ability, concerning the hazard function, was in decreasing order: Seasonal Cox, the three-parameter Gompertz, and the three-parameter Weibull, that was similar to the three-parameter logistic. The advantage of using the Cox model is that it is convenient for exploring the relationship between survival and several explanatory variables. The Cox model has the advantage of preserving the variable in its original quantitative form and of using a maximum of information. The survival analyses indicate that mosquito mortality is both age- and environment-dependent. © 2012 The Society for Vector Ecology.
Kouadio Y.K.,University of Fortaleza |
Servain J.,Fundacao Cearense de Meteorologia e Recursos Hidricos FUNCEME |
Servain J.,Institut Universitaire de France |
MacHado L.A.T.,National Institute for Space Research |
Lentini C.A.D.,Federal University of Bahia
Advances in Meteorology | Year: 2012
Relationships between simultaneous occurrences of distinctive atmospheric easterly wave (EW) signatures that cross the south-equatorial Atlantic, intense mesoscale convective systems (lifespan > 2 hour) that propagate westward over the western south-equatorial Atlantic, and subsequent strong rainfall episodes (anomaly > 10 mm·day-1) that occur in eastern Northeast Brazil (ENEB) are investigated. Using a simple diagnostic analysis, twelve cases with EW lifespan ranging between 3 and 8 days and a mean velocity of 8 m·s-1 were selected and documented during each rainy season of 2004, 2005, and 2006. These cases, which represent 50% of the total number of strong rainfall episodes and 60% of the rainfall amount over the ENEB, were concomitant with an acceleration of the trade winds over the south-equatorial Atlantic, an excess of moisture transported westward from Africa to America, and a strengthening of the convective activity in the oceanic region close to Brazil. Most of these episodes occurred during positive sea surface temperature anomaly patterns over the entire south-equatorial Atlantic and low-frequency warm conditions within the oceanic mixing layer. A real-time monitoring and the simulation of this ocean-atmosphere relationship could help in forecasting such dramatic rainfall events. © 2012 Yves K. Kouadio et al.
Alves J.M.B.,Fundacao Cearense de Meteorologia e Recursos Hidricos FUNCEME |
Campos J.N.B.,Federal University of Ceará |
Servain J.,Fundacao Cearense de Meteorologia e Recursos Hidricos FUNCEME |
Servain J.,IRD Montpellier
Water Resources Management | Year: 2012
This study investigated the sensitivity of a dynamic downscaling atmospheric model system coupled with a rainfall-runoff model to hindcast an example of reservoir water management in the semi-arid region of Northeast Brazil (NEB). A regional atmospheric spectral model (RSM) is driven by the outputs of an atmospheric general circulation model (AGCM), itself forced by the observed sea surface temperature over the World Ocean. Daily precipitation simulated by the RSM was then used as the input to a hydrological rainfall-runoff model for the Upper Jaguaribe River Basin to estimate inflows at the Orós Reservoir in the state of Ceará. A hindcast analysis of precipitation was performed during the rainy season over NEB (January to June) from 1971 to 2000. The RSM captured the precipitation variability relatively well when a probability density function (PDF) was used to correct the numerical bias. Three hindcast series of inflow using (i) the observed rainfall, (ii) the simulated rainfall before the PDF correction, and (iii) the simulated rainfall after the PDF correction were performed during the study period and then compared to the series of observed inflow. The atmospheric-rainfall-runoff "cascade" model efficiency was evaluated by comparing the Orós Reservoir release decisions from different scenarios based on observed, simulated (RSM, RSM-PDF), and mean historical reservoir inflows. The cascade model has the potential, relatively well balanced during dry, normal or wet years, to be a useful tool to correctly forecast the decision managements of reservoirs in the semi-arid region of NEB. Additional progress in the numerical simulation is however necessary to improve the performance. © 2011 Springer Science+Business Media B.V.
Projections of precipitation and temperature changes over Northeast Brazil using the dynamical downscaling technique [Projeções de mudanças na precipitação e temperatura no nordeste Brasileiro utilizando a técnica de downscaling dinâmico]
Sales D.C.,State University of Ceará |
Sales D.C.,Instituto Nacional do Semiarido INSA |
Costa A.A.,State University of Ceará |
da Silva E.M.,State University of Ceará |
And 7 more authors.
Revista Brasileira de Meteorologia | Year: 2015
This paper presents analysis of projected changes on precipitation and temperature perfomed by dynamical downscaling simulations in the CORDEX Project context. The simulation domain encompasses the Tropical Americas but the focus of this study is restricted to the Northeast Brazil subregions: North (NNEB) and South (SNEB). The regional model run in the simulations was RAMS6.0, forced by HadGEM2-ES global model data. The present period and three future time slices under the RCP8.5 climate scenario were analyzed. Current precipitation and temperature were compared against CRU observed data, to evaluate the performance and the biases from the regional and the global model. In comparison to the HadGEM2-ES model, RAMS6.0 is superior in someaspects as the phase representation of the annual precipitation and temperature cycle, reduction of the dry bias during the dry season over the NNEB and spatial distribution of the two variables, especially temperature. However, RAMS6.0 exacerbates some errors from the global model, like the wet bias in the rainy season. In the future climate, changes in the climatological value and annual mean fields of both variables were analyzed. Some patterns were projected by both models, like decreasing precipitation during austral winter and increasing temperature throughout the century. © 2015, Sociedade Brasileira de Meteorologia. All rights reserved.
Gutierrez A.P.A.,The World Bank |
Engle N.L.,The World Bank |
De Nys E.,The World Bank |
Molejon C.,The World Bank |
Martins E.S.,Fundacao Cearense de Meteorologia e Recursos Hidricos FUNCEME
Weather and Climate Extremes | Year: 2014
Large portions of Brazil's Northeast have experienced an intense and prolonged drought for the majority of 2010-2013. This drought, along with other droughts that have hit the South in recent years, has sparked a new round of discussions to improve drought policy and management at the federal and state levels. To assist with these efforts, the World Bank recently conducted a series of evaluations on national and sub-national drought preparedness measures and approaches across five country case studies. This particular article presents the Brazilian case study. The work draws from interviews with key experts and stakeholders, as well as document analyses, and focuses on preparedness measures and approaches at the national and one sub-national case; the state of Ceará. The analysis shows that although there is a rich history of drought management throughout Brazil, there are short-term and long-term gaps and opportunities on which decision makers might consider focusing to improve monitoring, forecasting, and early warning systems, vulnerability/resilience and impact assessments, and mitigation and response planning measures. © 2014 The Authors.
Muniz L.L.,Fundacao Cearense de Meteorologia e Recursos Hidricos Funceme |
Muniz L.L.,State University of Ceará |
Netto U.S.C.,Fundacao Cearense de Meteorologia e Recursos Hidricos Funceme |
Maia P.H.M.,State University of Ceará
ICEIS 2015 - 17th International Conference on Enterprise Information Systems, Proceedings | Year: 2015
Model-based testing (MBT) is an approach that takes software specification as the base for the formal model creation and, from it, enables the test case extraction. Depending on the type of model, an MBT tool can support functional and statistical tests. However, there are few tools that support both testing techniques. Moreover, the ones that support them offer a limited number of coverage criteria. This paper presents TCG, a tool for the generation and selection of functional and statistical test cases. It provides 8 classic generation techniques and 5 selection heuristics, including a novel one called minimum probability of path. Copyright © 2015 SCITEPRESS - Science and Technology Publications.