Dados de precipitação diária foram usados para determinar e classificar limiares da precipitação pluviométrica, assim como avaliar os impactos sociais, econômicos e ambientais decorrentes dos desastres associados às chuvas na cidade do Recife-PE. Com base na técnica dos quantis, a precipitação diária (P, em mm) foi dividida nas seguintes classes: Dia Seco (DS): P < 2,2; Chuva muito fraca (Cmf): 2,2 ≤ P < 4,2; Chuva fraca (Cf): 4,2 ≤ P < 8,4; Chuva Moderada (CM): 8,4 ≤ P < 18,6; Chuva Forte (CF): 18,6 ≤ P < 55,3; Chuva Muito Forte (CMF): P ≥ 55,3. Os resultados evidenciaram que quando há registros de precipitação dentro das classes de Chuva Muito Forte e Forte, sempre há escorregamentos e muitos pontos de alagamentos. As chuvas de intensidade Moderada também podem desencadear escorregamentos, principalmente pontos de alagamentos. Não houve ocorrência de danos associados à Chuva fraca, porém, quando há registros de precipitação em dias consecutivos anteriores a um evento de Chuva fraca, com acumulado superior a 30 mm, podem ocorrer escorregamentos. Dias consecutivos com chuvas anteriores a um evento de Chuva Muito Forte, Forte e Moderada contribuem ainda mais para a ocorrência de desastres. Apesar dos eventos extremos de chuvas intensas serem observados principalmente entre os meses de março e julho, tais eventos podem ocorrer nas demais épocas do ano. Verificou-se que é freqüente a ocorrência de escorregamentos e alagamentos decorrentes das chuvas, associada à falta de infra-estrutura, aliado principalmente às condições sociais e econômicas da população.Palavras-chave: Precipitação pluviométrica, quantis, impactos, desastres. Classification of Daily Rain and Impacts Resulting from Disasters Linked to Rainfall in the City of Recife-PE A B S T R A C TData of daily rainfall were used for determining and classifying the threshold values of rainfall as well as for evaluating the socioeconomic and environmental impacts of the disasters associated to the rains in the city of Recife-PE. Based on the technique of quantiles, the daily precipitation (R, in mm) was divided into the following classes: Dry Day: R < 2.2: Rain very weak (Rvw): 2.2 ≤ R < 4.2; Showers (Rw): 4.2 ≤ R < 8.4; Moderate rain (MR): 8.4 ≤ R < 18.6; Heavy Rain (HR): 18.6 ≤ R < 55.3; Very Strong Rain (VSR): R ≥ 55.3. The results showed that when there are records of precipitation within the classes of Strong and Very Strong Rain, there are always many points of landslides and flooding. Moderate intensity rains can also trigger landslides, particularly points of flooding. There was no occurrence of damage associated with Shower, however, when there are records of precipitation on consecutive days prior to an event Showers with accumulated more than 30 mm, landslides may occur. Consecutive days of rain prior to an event of Very Strong, Strong and Moderate Rain further contribute to the occurrence of disasters. Despite the extreme events of Heavy Rainfall are observed mainly between March and July, these events may occur in other seasons. It was found that the...

Several studies have shown that the increasing of planet's average temperature causes an intensification of the hydrological cycle, which may lead to changes in rainfall regimes, such as increasing of the occurrence of extreme hydrological events, modifying the water availability of a region and the quality of life of its population. The trend analysis of time series of rainfall is one of the ways to determine the occurrence of local climate changes. In this context, this work aims to estimate the trend in rates of climate change detection, referring to daily rainfall, defined by World Meteorological Organization (WMO), using the software RClimDex, and to evaluate the implications of these trends in river basins of the state of Grande parte dos pesquisadores acredita que as alterações climá-ticas que vêm acontecendo são consequências da atividade antrópica,

A B S T R A C TClimate change is a reality for the world's population and the evidence are part of our daily lives, with threats to the infrastructure of cities, decreased productivity in crops, changes in rivers and oceans. The objective of this study is to classify weather patterns in Agreste through Rain Anomaly Index (RAI), to characterize the severity of dry and moist years and analyze the disasters arising from climate variability. We selected 14 rain gauge stations distributed in the Agreste from 1963 to 2013. The annual RAI and the wet period were calculated. The survey of official data of disasters associated with extreme weather (dry and floods) of the 14 cities studied was conducted in 1963 to 2013, through the Integrated Information System of the Ministry of Integration of Disaster. The results indicated that the wet period corresponds to the months from February to July and the dry period from August to January. Through the RAI was diagnosed a change in the pattern of precipitation, showing that by the end of the 80s there is a higher frequency of wet years and that from the 90s there was a significant decrease in these years, i.e., the years dry now predominate in the region. In the drier classified official documents were issued decreeing state public and emergency disaster, caused by the drought and/or drought, with social impacts and huge losses in agriculture and livestock, in addition to human and pet supplies.

O Nordeste brasileiro, em destaque Pernambuco, apresenta grande variabilidade e irregularidade de chuvas, uma vez que esta é associada às oscilações das temperaturas dos oceanos Pacífico e Atlântico. Diante desta problemática, a pesquisa teve por objetivo analisar a influência dos eventos El Niño e La Niña sobre o regime de chuvas no Agreste de Pernambuco. Utilizaram-se dados mensais de precipitação pluviométrica de 30 estações localizadas no Agreste no período de 1963 a 2016, como também dados mensais do Índice Oceânico do Niño (ION). Foi realizada a climatologia mensal da região para identificar os períodos úmidos e secos da região. Em seguida, os eventos de El Niño e La Niña foram identificados e classificados de acordo com a intensidade dos fenômenos (Muito Forte, Forte, Moderado e Fraco), baseado nos valores do ION, e relacionados com a precipitação total anual. Por fim, correlacionou-se o ION com a precipitação pluviométrica trimestral, a partir do método de Pearson para identificar a influência sazonal. Verificou-se que o período chuvoso da região corresponde aos meses de março a julho, e o seco de agosto a fevereiro. Há dois padrões climáticos, um considerado úmido com maior número de anos chuvosos até o final da década de 80, e o segundo com aumento da frequência de anos secos a partir da década de 90. Os eventos de El Niño com intensidades variadas não explicam sozinhos os anos secos, assim como os eventos de La Niña não estão associados, necessariamente, a anos chuvosos. A interação desses fenômenos com os sistemas meteorológicos e o Dipolo do Atlântico é que são determinantes no regime de chuvas. Na análise sazonal, constatou-se que o ION exerce influência sobre o regime de chuvas, principalmente no período chuvoso.

This study investigates the effects of Lake Sobradinho, a large reservoir in Northeastern Brazil, on the local near-surface atmospheric and boundary layer conditions. For this purpose, simulations with the regional climate model COSMO-CLM are compared for two different scenarios: (1) with the lake being replaced by the average normal native vegetation cover and (2) with the lake as it exists today, for two different two-month periods reflecting average and very dry conditions, respectively. The performance of the simulation is evaluated against data from surface meteorological stations as well as satellite data in order to ensure the model’s ability to capture atmospheric conditions in the vicinity of Lake Sobradinho. The obtained results demonstrate that the lake affects the near-surface air temperature of the surrounding area as well as its humidity and wind patterns. Specifically, Lake Sobradinho cools down the air during the day and warms it up during the night by up to several ∘ C depending on the large-scale meteorological conditions. Moreover, the humidity is significantly increased as a result of the lake’s presence and causes a lake breeze. The observed effects on humidity and air temperature also extend over areas relatively far away from the lake.