This dissertation provides three distinct perspectives on state rainy day funds. The first empirical chapter explores the factors that influence a state to access their rainy day fund, and a variety of economic, institutional, and political factors to be important. The influence and effects of these factors, however, are contextual, and vary depending on the economic environment and political control. The most important influences on accessing the rainy day fund, however, are economic indicators that are in line with the purpose of state rainy day funds. The second empirical chapter investigates the influence of state rainy day fund deposit and withdrawal rules on where lawmakers place savings. The findings reveal that when states have strict rule configurations that limit legislative discretion, lawmakers avoid placing savings in the formal rainy day funds and opt for informal savings that allow for easier access. The final empirical chapter examines if states save enough to handle their unique economic environments. This chapter replicates Joyce's (2001) study with longitudinal data to gain a better understanding of state savings behavior and economic environments. Additionally, this chapter posits that informal and formal rainy day fund savings are closely linked, and, therefore, scholars need to consider both accounts when determining if states save enough their unique economic environment. Results indicate that under a broader view of state savings behavior and volatility, states are in a much better position than Joyce originally reported. What is more, when we consider both formal and informal savings, states are in a very good position to handle average volatility.

Yes / Building roofs represents a critical pathway for sediment mixing with rainwater. This study aims to explore the correlation between roof-top deposited sediment matter in the different areas of the Ikorodu Local Government Area in Lagos, Nigeria. The deposition rate on the roof was studied for 34 weeks in total (i.e., 17 weekly analyses in the rainy season and 17 weekly analyses in the dry season). The total deposition was collected by a 10 inch funnel and directed into a 5 L container, which was partially filled with sterilised water. The roof-top deposition in four different areas was inspected and analysed. The four areas were selected based on the levels of sanitation and vege-tation. The experimental results showed that the enumerated total depositions in different areas were higher in the dry season than the rainy season, with the highest deposition occurring in the Harmattan period. The data obtained from this study have evidenced that the contamination from roof-harvested rainwater can mainly be attributed to atmospheric deposition. Another key factor was the hygiene and sanitation of the harvesting areas, including the gutter, pipes and proximity to animal faeces.

Submitted by Lucienne Costa (lucienneferreira@ufcg.edu.br) on 2018-08-13T19:06:36Z No. of bitstreams: 1 LADY LAYANA MARTINS CUSTÓDIO – DISSERTAÇÃO (PPGMET) 2017.pdf: 2210710 bytes, checksum: 55d1c243d2dffba97fddd5fcb1e2b54b (MD5) / Made available in DSpace on 2018-08-13T19:06:36Z (GMT). No. of bitstreams: 1 LADY LAYANA MARTINS CUSTÓDIO – DISSERTAÇÃO (PPGMET) 2017.pdf: 2210710 bytes, checksum: 55d1c243d2dffba97fddd5fcb1e2b54b (MD5) Previous issue date: 2017-03-03 / Capes / Buscou-se avaliar neste trabalho as precipitações da EC e da PEC do LNEB e Roraima, bem como a relação entre esta variável nas duas áreas de estudo objetivando entender melhor os sistemas precipitantes que causam a EC, que, em geral, ocorre no trimestre abril, maio e junho, portanto, fora do período de monções na AS. Bem como verificar a relação da precipitação do LNEB e Roraima com a TSM do Pacífico Equatorial e Atlântico Tropical. Para tanto, utilizou-se de dados diários de precipitação de 1979 a 2013, provenientes do CFSR do NCEP, além dos dados do projeto Era-Interim do ECMWF de mesmo período e por fim, dados mensais oceânicos das regiões do El Niño e dos setores do Atlântico no período de 1982 a 2013. A princípio, calculou-se os ciclos pêntadais da precipitação, no qual, analisou-se as séries temporais das áreas de estudo e padrões atmosféricos associados. Usou-se o método hierárquico aglomerativo de Ward para classificar as regiões homogêneas de precipitação de ambas as áreas de estudo. A relação entre a TSM e a precipitação do LNEB e em Roraima e entre as precipitações destas áreas foi estimada pelo coeficiente de correlação de Pearson. Os resultados obtidos mostraram três grupos homogêneos de precipitação em Roraima e dois no LNEB. Em média a EC para as áreas de estudo tem início na pêntada 17 e final na pêntada 40. A PEC para LNEB e Roraima mostrou-se inconsistentes, pois dos cinco grupos de precipitação, em quatro, o número de ocorrências de PEC foram abaixo da metade da série histórica. As altas pressões ao nível do mar dos setores do Atlântico exercem função fundamental na contribuição da EC do LNEB e Roraima. Também se verificou que o ENOS tem papel relevante nas variabilidades interanuais da precipitação do LNEB e de Roraima, tanto nos totais anuais como nos da EC. As chuvas em Roraima apresentam correlação estatisticamente significativa com a TSM do norte do Atlântico, e as da região do Agreste do LNEB com a TSM do Atlântico Sul. Observou-se que as variabilidades interanuais dos totais anuais e sazonais de precipitação de Roraima e LNEB estão em fase, ou seja, em geral, os anos chuvosos em Roraima são os mesmos do LNEB, assim como os secos. As conclusões mais relevantes foram: a EC em Roraima possui regime tipo monções de surgimento brusco e término lento, enquanto a do LNEB apresenta transição gradual, configurando um regime diferente dos de monções; os sistemas meteorológicos produtores de precipitação nas duas regiões são diferentes, porém atuam na mesma época do ano; a marcha anual dos totais pentadais de precipitação ao longo do ano são as mesmas e são influenciados pelo ENOS e pela intensidade e posição das altas pressões do Atlântico resultando em variabilidades interanuais da precipitação em fase nas duas regiões. / The aim of this study was to evaluate the precipitations of the RS and PRS of the ENEB and Roraima, in addition to the relation between this variable in the two study areas for the sake of getting a better understanding of the precipitating systems that cause RS, which generally occurs in the quarter of April, May and June, thus outside the monsoon period in SA. Additionally the study aimed to verify the relation of the precipitation of the ENEB and Roraima with the SST of the Equatorial Pacific and Tropical Atlantic. In order to do so, daily precipitation data from 1979 to 2013 from the NCEP CFSR were used, apart from Era-Interim data from the ECMWF project of the same period and, finally, monthly ocean data from the El Niño regions and the Atlantic sectors from 1982 to 2013. At first, the 5-days cycles of the precipitation were calculated, in which the time series of study areas and the atmospheric patterns associated were analyzed. Ward's agglomerative hierarchical clustering method was used to classify the homogeneous precipitation regions of both study areas. The link between the SST and precipitation in ENEB and Roraima and between precipitations in these areas was estimated by the Pearson correlation coefficient. The results obtained showed three homogeneous groups of precipitation in Roraima and two in the ENEB. On average, the RS for the study areas starts at the 17 pentad and at the end at the 40 pentad. The PRS for ENEB and Roraima appeared to inconsistent, because among the five precipitation groups, four of them presented a number of PRS occurrences below half of the historical series. The high sea-level pressure of the Atlantic sectors play a fundamental role contributing to the ENEB and Roraima RS. It was also verified that the ENSO has a relevant role in the interannual variability of the ENEB and Roraima precipitation, both in the annual totals and in the RS. The rainfall in Roraima shows a statistically significant correlation with the SST of the North Atlantic, and those of the Agreste region of the ENEB with the SST of the South Atlantic. We observed that the interannual variabilities of the annual and seasonal precipitation totals of Roraima and ENEB are in-phase, that is, in general, the rainy years in Roraima are the same as in the ENEB, in addition to the dry ones. The most relevant conclusions were: the RS in Roraima has a monsoon type regime with abrupt onset and slow ending, while the ENEB has a gradual transition, forming a regime different from that of the monsoons; the meteorological systems producing precipitation in the two regions are different, however acting at the same time of year; the annual marching of the pentad totals of precipitation throughout the year are the same and are influenced by the ENSO and the intensity and position of the high pressure of the Atlantic, resulting in interannual variabilities of the precipitation in phase in the two regions.

The objective of this study was to determine the characteristics of the growing season and dry spells based in daily rainfall data in Rio Largo, Alagoas. A serie time with 36 years of daily precipitation data (1973 - 2008) was measured in the conventional station (9 ° 28'S 35 ° 49'W, 127m) of the Agricultural Science Center (ASC) of the Federal University of Alagoas (FUA). In the definition of dry days were used six different values of precipitation (0, 1, 2, 3, 4 and 5 mm). The day was considered dry when it has a rainfall of less than one of these six values and it was defined as wet if the rainfall w as higher. The dry periods were defined as the sequence of dry days with precipitation less than or equal to the reference value of precipitation. The beginning (potencial and success), end e length of the rainy season and cultivation were measured by using direct methods. Statistical analysis of rain occurrence and dry spell was done with Markov chain in the software Instat Climatic. The dry periods were defined in three different intervals (≥ 5 days, ≥ 7 days and ≥ 10 days). At 80% probability the rainy season began on April 7th and finished on October 24th with length of 221 days. The beginning of the rainy season was anticipated in La Niña years (10 days) and delayed in years of El Niño (9 days), and consequently, cause a decrease in length of growing season for El Niño years and increase in La Niña years. The highest occurrences of rainy days were observed between April to August (50 to 90%). And November was the driest month (65 to 97%). In the rainy season (March to August) the dry spell of 5 days was the one that had the greatest chance of occurrence (5 to 85%). The occurrence of dry spells was low for 7 days (0 to 45%) and 10 days (0 to 5%). The occurrences of dry spells were intensified by the occurrence of El Niño events (1 to 60%) between 1980 and 1983 and were reduced in years of La Niña events (0 to 45%) between 1983 and 1985. / Fundação de Amparo a Pesquisa do Estado de Alagoas / O objetivo desse trabalho foi determinar as características da estação de cultivo e os períodos secos baseado em dados diários de precipitação pluvial para o município de Rio Largo, Alagoas. A série de 36 anos de dados de precipitação pluvial diária (1973 2008) foi obtida na estação convencional (9°28 S, 35° 49 O, 127m) do Centro de Ciências Agrárias (CECA) da Universidade Federal de Alagoas (UFAL). Na definição de dia seco foram considerados seis diferentes valores de referência para a precipitação (0, 1, 2, 3, 4 e 5 mm). O dia foi considerado seco quando possuiu precipitação igual ou inferior a um desses valores e definido como chuvoso em caso contrário. Os períodos secos foram definidos como a sequência de dias secos com precipitação menor ou igual ao valor considerado de referência de precipitação. O início (potencial e de sucesso), fim e comprimento da estação chuvosa e de cultivo foram definidos pela utilização de métodos diretos em função da precipitação pluvial e evapotranspiração de referência. As análises estatísticas de ocorrência de chuva e de períodos secos foram feitas através da cadeia de Markov no aplicativo Instat Climatic. Os períodos secos foram avaliados em três diferentes intervalos de tempo (≥ 5 dias, ≥ 7 dias e ≥ 10 dias). A 80% de probabilidade, a estação chuvosa iniciou-se no dia 07 de abril e terminou no dia 24 de outubro, com comprimento de 221 dias. O início da estação chuvosa foi antecipado em anos de La Niña (10 dias) e retardado em alguns anos de El Niño (9 dias), e assim, causa uma diminuição no comprimento da estação de cultivo para anos de El Niño e aumento em anos de La Niña. As maiores ocorrências de dias chuvosos foram observadas entre abril e agosto (50 a 90%), enquanto novembro foi o mês mais seco (65 a 97%). Na estação chuvosa (março a agosto), o período seco de 5 dias obteve as maiores chances de ocorrência (5 a 85%). A ocorrência de períodos secos foi baixa para 7 dias (0 a 45%) e 10 dias (0 a 5%). As ocorrências de períodos secos foram intensificadas pela ocorrência de eventos de El Niño (1 a 60%), entre 1980 e 1983, e reduzidas em anos de eventos de La Niña (0 a 45%) entre 1983 e 1985.

State government finance is a substantial endeavor in the United States. The management of a multitude of revenues and expenditures often involves some level of fiscal stress. In an age of increased public scrutiny, policymakers must be mindful of possible causes of fiscal stress, and the policy options available to mitigate fiscal stress and increase financial stability. This dissertation contains three essays that examine different elements of fiscal stress, and in some cases, the applicable policy responses. Chapter two examines rainy day funds and their countercyclical goal of reducing recessionary fiscal stress. This essay takes a different approach from much of the literature, by using forecast residuals to quantify fiscal stress as tax revenue volatility and searching for any relationship between rainy day funds and states that had greater volatility. Empirical results indicate states that experience positive residuals, that is actual tax revenues greater than the forecast trend line, had greater rainy day fund balances. Chapter three focuses on the problem of lost revenues facing states from e-commerce. Due to Supreme Court decisions, businesses that do not have a physical location, or nexus, in a state are not required to collect sales and use taxes. To date, the policy response to lost revenue that has gained the most traction is the Streamlined Sales and Use Tax Agreement. Results indicate that states with local option sales taxes and higher sales tax rates were more likely to adopt this agreement. Chapter four scrutinizes state unemployment trust funds, which are used to fund state unemployment insurance programs. If state funds run short of money during recessions due to the larger number of individuals drawing benefits, then states must borrow from the federal government’s unemployment trust fund. This creates another liability that must be managed by state governments. Empirical findings show that several features of programs affect balances and the probability of taking a loan from the federal fund including the taxable wage base, weekly benefits, and unemployment tax rates. This dissertation concludes by summarizing the results and exploring future research possibilities on the three essay topics.

Since most of the inhabitants in West Africa is working with, or are dependent on agricultural work, accurate weather forecasts are important in their daily work. Knowledge of when to start to sow is one of the most important features from a farmer’s point of view. It can be devastating for the farmers if the soil is not moist enough when planting since the crops risks to dry out, but also planting too late needs to be avoided since it will affect the growing time and therefore might reduce the production. In this thesis, investigations whether the start of the rainy season in Ghana and parts of Burkina Faso is predictable, only with the use of patterns in rainfall and changes in sea surface temperature in the Gulf of Guinea. The region of interest has been divided into four equally sized areas with a latitudinal width of 2  from south to north. The models are first of all predicting the start of the rainy season in the southernmost area by use of four different methods, three that are based on precipitation patterns and one based on changes in sea surface temperature. Thereafter, the three northerly areas are predicted with a linear function based on when the rainy season started in the southernmost area. The results shows that the model is acceptable in its predictability but is very good in indicating if the rainy season will start earlier or later than the year before. This is of major benefits for the farmers in the region. On a long‐range average, the rainy season starts in the southernmost area first and then it starts further north, but this is not always the case in individual years, which makes the models complicated to use in some years. In order to give reliable forecasts to the farmers, the rainy season needs to be defined so it fulfils the conditions that are needed for plants to grow. Therefore, the start of the rainy season is defined as when 40 mm of precipitation is received during a five‐day period with at least 16 mm in one of these five days. Thereafter, the next 30 days cannot contain more than 18 days without precipitation. / Eftersom de flesta invånarna i Västafrika arbetar med, eller är beroende av jordbruksarbete så är väderprognoser till stor hjälp i det dagliga arbetet. Att ha kännedom om när det är lämpligt att börja så är en av de viktigaste aspekterna ur böndernas perspektiv. Att börja så innan marken är tillräckligt fuktig kan leda till förödande konsekvenser för bönderna då grödorna riskerar att torka ut och dö, men även att vänta för länge med att så bör undvikas eftersom det påverkar längden på skördesäsongen och därmed också produktionen. I den här studien har det gjorts undersökningar om det är möjligt att göra prognoser för när regnperioden börjar i Ghana och delar av Burkina Faso med hjälp av nederbördsfördelningen och förändringar i ytvattentemperaturen i Guineabukten. Regionen har delats in i fyra lika stora områden med latitudinell bredd på 2 ° från söder till norr. Modellerna börjar med att göra en prognos för regnperiodens början i det sydligaste området med hjälp av fyra olika metoder, tre som är baserade på nederbördsfördelningen och en som är baserad på ändringar i ytvattentemperaturen. Därefter görs prognoser för de tre nordligare områdena med hjälp av en linjär funktion baserad på när regnperioden började i det sydligaste området. Resultaten visar att modellen är acceptabel när det gäller att komma så nära den verkliga starten som möjligt, men är väldigt bra på att indikera om regnperioden kommer att börja tidigare eller senare än året innan. Detta är till stor nytta för bönderna i området. Över ett längre perspektiv så börjar regnperioden först i det sydligaste området för att sedan börjar längre norrut, men så ser det inte ut i varje enskilt år, vilket gör att modellerna inte är användbara alla år. För att kunna ge bönderna så bra prognoser som möjligt så behöver regnperioden definieras så att den uppfyller de villkor som krävs för att de ska kunna börja så. Därför har regnperiodens början definierats som när 40 mm nederbörd mottagits under en femdagarsperiod med minst 16 mm under en av dessa fem dagar. Därefter får de närmaste 30 dagarna inte innehålla mer än 18 dagar utan nederbörd.

No description available.

207 postes pluviométriques de l’Agence brésilienne sur l’eau (ANA) dans le sud de l'Amazonie et au nord du Cerrado sont analysés, tout en utilisant des tests non-paramétriques de Pettitt qui identifie les ruptures dans les séries chronologiques de pluviométrie, le test de Mann-Kendall qui détecte des tendances annuelles et saisonnières des indices pluviométriques, ainsi qu’un modèle de régression linéaire qui identifie les tendances subtiles de croissance ou décroissance dans les précipitations. Le test de Pettitt a indiqué 16% des ruptures dans les séries chronologiques des précipitations, et le test mensuel/saisonnière de Mann-Kendall a mis en évidence que 41% des postes ont des tendances négatives, principalement dans les saisons de transition (début et fin de la saison de pluie). Le modèle de régression linéaire a montré que 63% des données ont présenté des tendances négatives. Et en fine échelle les données temporelles nous ont permis d’identifier les dates de début et fin de la saison des pluies. Les résultats suggèrent qu'il existe de forts contrastes entre l'Amazonie et le Cerrado. Cette analyse chronologique a également indiqué que durant la période couverte par l’étude il y a eu un retard dans le début de la saison des pluies pour 84% des postes pluviométriques, et pour la fin un décalage prématuré de 76%, et pour son ampleur une diminution en 88%. L’analyse de krigeage exponentielle ordinaire des postes pluviométriques dans les zones déboisées a également révélé qu’il y a d’importantes chances que la déforestation soit un adjuvant à l'affaiblissement de la saison des pluies, en particulier dans les zones fortement déboisées de l’État de Mato Grosso et les régions au nord de l’État de Rondônia. Dans ce travail, des séries chronologiques des précipitations sont mises en corrélation avec des données d’occupation du sol, acquises par des images satellites Landsat 5, à partir d'une perspective temporelle. Cette analyse des zones tampons (1-50km) est divisée par 3 périodes de couverture forestière (avant 1997, parmi 1997-2010 et 2010) a indiqué que sur le plan local, au niveau des précipitations, il n’existe pas de corrélation. Pourtant, la méthodologie des zones tampons a suggéré que dans les grandes zones forestières, elle peut éventuellement s’appliquer. Malgré que les données climatiques ne montrent pas decorrélation significative avec les données de la couverture forestière, les analyses de Pettit, Mann-Kendall, la régression linéaire et l'identification de la saison des pluies rejoignent des découvertes récentes sur les modèles de circulation de large-échelle / 207 Rain Gauges (RG) of the Brazilian National Agency for Water (ANA) were analyzed using statistical non-parametrical tests. The Pettitt’s test identified ruptures in the chronological rainfall series, while the Mann-Kendall’s test detected annual and seasonal tendencies in rainfall indexes and a linear regression analysis identified slight gain or loss in precipitation. Pettitt’s test indicated 16% of ruptures in the chronological rainfall series at the same time as Mann-Kendall’s monthly test put in evidence 41% of the RG having negative trends in transition seasons (onset and offset of the rainy season). Lastly the linear regression analysis showed 63% of data having negative trends. Additionally the dates of onset and offset of the rainy season were identified and its results submitted to Mann-Kendall’s and the linear regression approach. The data suggests strong contrasts between the Southern Amazon and the Northern Cerrado showing a delay on the onset of the rainy season for 84% of the RG, a premature offset for 76% and a reduction in the rainfall seasonal extend for 88%. An exponential ordinary kriging analysis of RG in deforested areas also revealed major chances of deforestation areas working as an adjuvant in the weakening of the rainy season- especially in highly deforested areas of the Mato Grosso State and the northern Rondônia. Aiming to build a tool to detect interactions between land surface and rainfall patterns the207 RG were correlated through a buffer zones analysis with land use data acquired from satellite LANDSAT 5. The time frame previously selected was divided into three periods of forest cover (before 1997, between 1997-2010 and acumulated for 2010). The cross-related buffer zones analysis (1-50km) indicated at local level that precipitation patterns are not well correlated to forest cover. Yet the buffer zones methodology suggested that as larger the forest areas are, larger are the probabilities of those influencing precipitation at regional scale, contrary to forest fragments in local level. Despite the climatic data in the buffer analyzes do not reveal significant correlation to forest cover, the statistic Pettit and Mann-Kendall tests, the linear regression analyzes and the identification of the rainy season, confirmed a fine linkage with recent findings which focus large-scale circulation models including forest cover as a variable / Este estudo analisou 207 estações pluviométricas da Agência Nacional das Águas (ANA) no Sul da Amazônia e no Cerrado no período de 1970-2010, utiizando-se dos testes estatísticos não-paramétricos de Pettitt que identifica rupturas nas séries cronológicas pluviométricas, o teste de Mann-Kendall que detecta tendências anuais e sazonais dos índices pluviométricos, e uma análise de regressão linear que identifica tendências sutis de acréscimo ou decréscimo nas precipitações. O teste de Pettitt indicou um total de 16% de rupturas nas séries cronológicas de chuva enquanto que o teste sazonal/mensal de Mann-Kendall coloca em evidência que 41% das estações apresentam tendências negativas principalmente nas estações de transição (início e fim da estação chuvosa). Já a análise de regressão linear indicou que 63% dos dados apresentam tendências negativas nas precipitações. Como complemento também foram identificadas as datas do início e fim da estação chuvosa. Esta se deu por meio da adaptação de método estatístico atrelado às análise de tendências de Mann-Kendall e de regressão linear. Os resultados sugerem fortes contrastes entre o Sul Amazônico e o Cerrado. Esta análise cronológica do período chuvoso indicou o atraso significativo no início da estação chuvosa para 84% das estações, e um fim prematuro em 76%, além da redução do período em 88% dos casos. Por fim, foi desenvolvido,examinado e verificado a correlação de dados climáticos e cobertura do solo através da análise climática oriunda da regressão linear, e da classificação do uso da terra adquiridos do satélite LANDSAT 5 a partir de uma perspectiva temporal. A correlação dos dados delimitados por zonas tampão de 1-50km e divididos em 3 períodos cronológicos anteriores a 1997, entre 1997-2010 e o acumulado de 2010 contemplam o total de floresta. As análises indicam que os padrões de precipitação local não são correlacionados diretamente a cobertura florestal. No entanto, a metodologia de zonas tampão sugere que quanto maiores as áreas de floresta, maiores são as probabilidades destas influenciarem as precipitações, ao contrário de pequenos fragmentos florestais como indicado nos resultados das correlações até 50km. Apesar dos dados climáticos não mostrarem correlação significativa com os dados da cobertura florestal, as análises dos testes de Pettit, Mann-Kendall, regressão linear e de identificação do período chuvoso vão em direção de descobertas recentes com foco nos modelos de circulação em larga-escala, que incluem a cobertura florestal como variável

A cana-de-açúcar é um dos principais produtos agrícolas cultivados no Brasil. O País é o maior produtor de cana-de-açúcar do mundo, sendo que o Estado de São Paulo é responsável por 57,5 % da produção brasileira. Como em qualquer outra cultura, as condições atmosféricas constituem um dos principais fatores responsáveis pela quebra na produtividade. A fim de determinar as regiões paulistas mais susceptíveis a eventos de tempo prejudiciais ao cultivo canavieiro, principalmente com relação ao déficit hídrico, foram calculadas as probabilidades de ocorrência de períodos secos no Estado para o período de 1971-2003. Os resultados mostraram que as regiões centro-norte e centro-oeste paulistas são as que possuem condições pluviométricas mais adequadas às exigências hídricas da cana-de-açúcar, com estações seca e chuvosa mais bem definidas do que nas demais regiões. Foram encontradas seis regiões homogêneas dentro do Estado quanto ao regime de precipitação, sendo que quatro destas são áreas canavieiras. Para estas quatro regiões, foram determinadas as datas de início e fim da estação chuvosa, de modo a selecionar veranicos que ocorreram dentro da mesma e que possam ter prejudicado a produção de cana no Estado. Para esses períodos, foram construídos campos médios para diferentes variáveis meteorológicas, defasados no tempo em até 3 pêntadas. A comparação entre os campos médios obtidos e campos observados em sete episódios de veranicos mostra que o campo de divergência de massa é o mais indicado na previsão dos mesmos, com 70 a 100 % de semelhanças nas características meteorológicas identificadas. Por fim, análises foram feitas sobre a existência de mudanças no padrão de precipitação das regiões canavieiras paulistas. Foi possível concluir que a quantidade de chuva acumulada nos meses de DJF apresentou tendência de aumento no período 1937-2003, assim como o número de dias de chuva maior que 1 mm, indicando um aumento do número de eventos extremos de precipitação. A análise da tendência da estação chuvosa nas quatro regiões homogêneas de interesse mostrou antecipação (atraso) no início (fim) da época das chuvas no interior do Estado, ocasionando um prolongamento na duração da estação chuvosa. / Sugarcane is one of the major agricultural products grown in Brazil. The country is the largest sugarcane producer in the world, and São Paulo State accounts for 57,5 % of Brazilian production. As in any other culture, the weather conditions play an important role on production losses. In order to identify the most vulnerable State regions for sugarcane cultivation, especially with respect to hydric deficit, the probabilities of dry spells in the State were calculated for the 1971-2003 period. The results showed that the rainfall conditions on the northern central and midwestern regions of São Paulo are the ones that better fulfill sugarcane water requirements, with wet and dry seasons better defined in comparison with the other regions. Based on precipitation, six homogeneous regions were determined inside the State. Four of these regions are sugar-cane production areas. The onset and end of the rainy season in these four regions were investigated in order to select dry spells that might have hindered the production of sugarcane in the State. Lagged mean atmospheric fields based on these dry spells were constructed. Comparisons between mean and observed fields during seven different dry spells showed that the divergence field is the one that can be best used in the forecast of dry spells, with resemblance of 70 to 100 % on meteorological characteristics and its mean values. Finally, tests were made in order to investigate the existence of changes in precipitation patterns over the productive regions of São Paulo. Results led to the conclusion that the amount of precipitation accumulated during de DJF trimester tended to increase during the 1937-2003 period, as well as the number of days with rainfall greater than 1 mm, indicating that the extreme precipitation events has possibly also increased. The trend analysis of the rainy season in the four homogeneous regions of interest showed early (late) start (end) of the rainy season in the countryside, causing a more extended rainy season.

Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / This work was carried out in the county of Valen?a - RJ, with the objective to evaluate production and quality of the stargrass, in function of: two irrigation levels (with and without); four cut intervals (21, 28, 35 and 42 at the rainy season and 28, 35, 42 and 49 days at the dry season of the year); as well as four levels of nitrogen (0, 150, 300 e 600 kg/ha/year). The dry matter production (DMP) and the efficiency of the nitrogen utilization (ENU) in plots of 6,25 m2, were estimated from October 2004 to October 2005. In the months of January, June/July and September/October samples were collected to determine chemical composition and digestibility such as: crude protein (CP), neutral-detergent fiber (NDF) and in vitro dry matter digestibility (IVDMD). The Irrigation when increased DMP and ENU, reduced the forrage quality and only had significative effect (P<0,05) during the rainy season. The harvest intervals does not affected (P>0,05) on DMP. However, there was tendency to increase. Harvest intervals should be 42/49 days to obtain good forage quality and yield. The chemical composition and digestibility of the dry matter decreased with the spacing of the cuts and the effect of the interval of cuts on ENU was dependent of the irrigation. At that time it dries the irrigated treatments had her ENU increased with the decrease of the frequency of the cut. The nitrogen fertilization was the only factor that increased (P<0,05) DMP and the quality of the stargrass. However, the answer of DMP to the nitrogen fertilization was reduced and ENU was not affected in function of the nitrogen levels. In the conditions of experiment was realized, it is approved as the most appropriate handling of the studied factors: The interval of cuts of 42/49 days, that formed an alliance high yield with a satisfactory quality and the irrigation, only accomplished in favorable climatic conditions. / Este trabalho foi conduzido no munic?pio de Valen?a - RJ, com o objetivo de avaliar a produ??o e a qualidade do capim-estrela, em fun??o de: dois regimes h?dricos (irrigado e n?o-irrigado); quatro intervalos de cortes (21, 28, 35 e 42 na ?poca chuvosa e 28, 35, 42 e 49 dias na ?poca seca do ano); e quatro doses de nitrog?nio (0, 150, 300 e 600 kg/ha/ano). Durante o per?odo de outubro de 2004 a outubro de 2005, foram estimadas a produ??o de mat?ria seca (PMS) e a efici?ncia da aduba??o nitrogenada (EAN) em parcelas de 6,25 m2. Nos meses de janeiro, junho/julho e setembro/outubro coletaram-se amostras para a estimativa do valor nutritivo e digestibilidade, determinando a prote?na bruta (PB), a fibra em detergente neutro (FDN) e a digestibilidade in vitro da mat?ria seca (DIVMS). Os resultados mostraram que a irriga??o aumentou a PMS e a EAN, reduziu o valor nutritivo e DIV da mat?ria seca. Entretanto somente houve resposta (P<0,05) ao regime h?drico apenas quando as condi??es clim?ticas n?o foram limitantes ao crescimento da forrageira. O intervalo de cortes n?o alterou (P>0,05) a PMS, embora tenha sido observada a tend?ncia de incremento da mesma em fun??o da diminui??o da freq??ncia de cortes, sendo a maior produ??o obtida nos tratamentos 42/49 dias. A qualidade da forrageira diminuiu com o espa?amento dos cortes e o efeito do intervalo de cortes sobre a EAN foi dependente da irriga??o. Na ?poca seca do ano os tratamentos irrigados tiveram sua EAN aumentada com a diminui??o da freq??ncia do corte. A aduba??o nitrogenada foi o ?nico fator que aumentou (P<0,05), simultaneamente, a PMS e a qualidade do capim-estrela. No entanto, a resposta da PMS ? aduba??o nitrogenada foi pequena e a EAN n?o foi alterada (P>0,05) em fun??o das doses de nitrog?nio. Nas condi??es experimentais, preconiza-se como o manejo mais adequado: o intervalo de cortes de 42/49 dias, que aliou rendimentos elevados a uma qualidade satisfat?ria; e a irriga??o deve ser usada apenas quando as condi??es clim?ticas s?o favor?veis.