SPATIOTEMPORAL VARIATION IN THE PRECIPITATION OF THE AMAZON COASTAL ZONE: USE OF REMOTE SENSING AND MULTIVARIATE ANALYSIS

Reliable data on the spatiotemporal variability in precipitation patterns are vital to the development of effective public policies for environmental management. The analysis of the variation in rainfall rates is currently limited severely by the dependence on data from rain gauges, in particular in regions with a relatively sparsely-distributed network of meteorological stations, as in the Amazon region. The present study investigated the variability in the precipitation and the principal rainfall patterns at different time scales in the coastal zone of the Amazon region, and associated these patterns with the precipitant meteorological systems present in the region. The study was based on the application of remote sensing (CMORPH) data taken at half-hourly intervals on a 0.088 latitude/longitude scale. The spatiotemporal variability in the region’s precipitation was analyzed at different time scales (monthly, seasonal, and annual), with distribution patterns being assessed using a Principal Components Analysis (PCA). The estimates obtained from the CMORPH data provided a satisfactory overview of the precipitation climatology of the study region at the distinct time scales. The PCA identified a precipitation gradient in the two principal pluviometric modes, which together explained 88% of the total variance in the data. The first mode explained 83% of the variance, with two distinct periods, a rainy season and a dry (or less rainy) period, which are influenced by large-scale precipitant systems, the Intertropical Convergence Zone (ITCZ) and High Level Cyclonic Vortices (HLCVs). The second mode, which explains 5% of the variance in the rainfall data, is associated with mesoscale systems that affect primarily the transition periods between the seasons, and depend on the southern extreme of the annual shift in the ITCZ. The understanding of the variation of precipitation patterns using high-resolution CMORPH data, with a comprehensive coverage in both time and space, provides an effective tool for the establishment of public policies at a municipal level, in particular the development of models, and the mediation of the vulnerability of local populations to climatic extremes

Management of estuarine beaches on the Amazon coast though the application of recreational carrying capacity indices

The purpose of this paper is to determine the Recreational Carrying Capacity of three estuarine beaches (Colares, Marudá and Murubira) on the Amazon coast of Brazil, based on the combined assessment of natural conditions and visitor facilities. In the final analysis, the carrying capacity of Colares beach was estimated to be 1089 visitors per day, and that of Murubira beach, 238 visitors per day. At Marudá beach, however, the inadequate quality of the water resulted in an RCC of zero, indicating that the beach should not be visited for recreational use. The results of this study may provide a valuable diagnostic tool for the development of future state and municipal coastal management programs. We believe that the procedures adopted in this study are applicable to other estuarine beaches on the Amazon coast, as well as in other estuarine beaches elsewhere with similar natural characteristics.Peer ReviewedPostprint (author's final draft

Federal conservation units in the Brazilian amazon coastal zone: an adequate approach to control recreational activities?

Coastal tourism usually is of enormous interest to local coastal communities due to its potential for the creation of jobs and the generation of income. Within this context, beaches are the main resource since they comprise a rich diversity of natural ecosystems and landscapes, as well as historical and cultural features, such as local gastronomy.Peer ReviewedPostprint (author's final draft

Use and ocupation in a fishery community in the margin of Caeté river estuary (PA, Brazil)

This work was carried out in Bacuriteua, situated in the northeast “paraense” coastal zone in themargin of the Caeté river estuary. To characterize the type of uses and occupation in the studied area itwas necessary to define: (i) users´s profile, (ii) type of uses of the natural resources, (iii) type ofservices and infrastructures, and (iv) type of local buildings, to subsidy future and necessary plans ofcoastal management in the bragantinian region. The work was carried out through direct observation,tasks and questionnaires applied to the local inhabitants. The majority of the interviewed work withfishery resources and did not present complete elementary school. The pressures on the natural resourcesuse among some local agents associated to immigration rates, failure of basic hydric canalization,urban daily cleanness and public illumination, absence of potable water net, amongst others were themain factors responsible for some social and environmental problems e.g. over exploration of thebiologic resources, urban growth, decrease of public benefit, illness, amongst others. According to theactual socioeconomic status in the study area it is necessary the implementation of measures of coastalmanagement to improve the environmental status and the life quality of the local inhabitant.Este estudo foi realizado no povoado de Bacuriteua-PA, localizado na zona costeira do nordeste paraense,às margens do estuário do rio Caeté. Para caracterizar o tipo de uso e ocupação na área em estudo foinecessário definir: (i) perfil socioeconômico da população local, (ii) tipo de uso dos recursos naturais,(iii) tipo de serviços e infra-estruturas e (iv) tipo de construções locais, para subsidiar futuros e necessáriosplanos de gerenciamento costeiro na região bragantina. Os estudos foram realizados por observaçãodireta e uso de questionários aplicados à população residente. O levantamento censitário definiuque a maioria das pessoas trabalha direta ou indiretamente com recursos pesqueiros e tem apenas oensino fundamental incompleto. As pressões sobre o uso dos recursos naturais, entre os vários agenteslocais, associados a fatores como imigração, carência de saneamento básico, coleta periódica de lixo eiluminação pública, ausência de rede de abastecimento de água potável, entre outros, foram os principaisresponsáveis por gerar vários problemas de caráter socioambiental, p. ex. sobre-exploração dosrecursos biológicos, crescimento populacional, redução de benefícios públicos à população, presençade vetores de doenças, etc. Deste modo, perante a atual situação socioambiental faz-se necessária aimplantação de medidas de gerenciamento costeiro, para melhorar a qualidade ambiental e de vida dapopulação local

Processos morfodinâmicos em uma praia de macromaré no litoral amazônico

Processos oceanográficos na zona costeira amazônica resultam da integração de várias forçantes (e.g., macromarés, moderada energia de ondas, correntes de elevada intensidade, alta descarga fluvial e ventos de fortes intensidades) que são responsáveis por contínuas mudanças no perfil praial. O objetivo deste estudo foi compreender as mudanças na morfologia praial relacionadas a parâmetros como a elevação da maré (TR), a altura da onda (Hb), o período da onda (T) e a velocidade de queda adimensional dos sedimentos (ws). O estudo foi realizado em uma praia arenosa (praia de Ajuruteua-PA) durante períodos equinociais (março de 2009, coincidindo com o período chuvoso e setembro de 2009, período seco) e não equinocial (dezembro de 2008, período seco e junho de 2009, período chuvoso). Equipamentos oceanográficos foram fundeados por 25h em cada mês de coleta. As amostras superficiais de sedimentos foram coletadas ao longo do perfil de praia, entre a zona de dunas e o início da antepraia. Em laboratório, a granulometria foi realizada utilizando um agitador automático com peneira variando de -1.0 to 4.0 f. As marés são semi-diurnas e assimétricas, com períodos de vazantes mais longos (6,5 e 7,5 h). A oscilação da maré durante as sizígias varia entre 4,0 e 5,5 m. Na área predomina a corrente de maré com direção SE-NW durante a maré vazante e de NW-SE durante as marés enchentes. As velocidades das correntes são maiores durante os períodos de enchente (até 0,7 m/s). Durante a maré baixa, o estirânico possui cerca de 250-300 m. Esta praia é composta por areia fina (2,6-2,8f).  As ondas são modulados sobre os bancos de areia, de acordo com a fase da maré, com alturas mínimas de ondas Hs durante a maré vazante, mas superior a um metro durante a preamar. Os valores de RTR e Ω são claramente modulados de acordo com a fase da maré. Durante condições de alta energia, a praia apresenta característica de planície de maré, enquanto que durante condições de baixa energia apresenta características ultradissipativa

Challenges of the recreational use of Amazon beaches

The Amazon coast is characterized by a heterogeneous landscape, ranging from zones of intense urban development to sparsely-populated areas with little or no infrastructure or public services (Szlafstein, 2012). The most popular beaches are subject to unplanned development, which has created a range of natural and anthropogenic hazards, related primarily to the erosion provoked by inadequate constructions, bacteriological contamination from sewage outfalls, litter pollution, and oil spills (Andrade et al., 2010; Pereira et al., 2014; Sousa et al., 2017). As these processes can affect the development of the tourism industry, effective regulation and planning is urgently required for the whole Amazon coast, in order to guarantee the establishment of a secure and sustainable tourist industry, with a minimum of hazards and risks for beach users. In this context, the principal objective of the present study was to describe the natural and social characteristics of sandy Amazon beaches, evaluating their recreational potential and the challenges for the development of the recreational use of those beaches. The following description outlines the environmental and social features of these sandy beaches that determine their potential for recreational and leisure activities, and the challenges for the development of the local tourism industry. Finally, a number of recommendations are presented for the improvement of the recreational use of coastal. Amazon beaches.Peer ReviewedPostprint (author's final draft

Hydromedusae composition, occurrence, and distribution in the Caeté river estuary, Pará

Species composition and spatio-temporal variation in density of hydromedusae along a salinity gradient were investigated in the Caeté river estuary, northern Brazil in June and December, 1998 (dry season) and in February and May, 1999 (rainy season). The Caeté river estuary was characterized by high spatial and temporal variations in salinity. Twelve taxa were recorded of which Octocanna haeckeli represent to new record for coastal waters of the northeast coast of Pará state. In general, the highest and lowest densities were found in December and May, respectively. This observation was probably due to differences in the rainfall rates between the two studied periods

Use and occupation at the Ajuruteua beach (PA, Brazil)

The village of Ajuruteua is located in a beach of the northeast littoral of Para State at 36 km fromBragança city and presents a population of 392 people living there (2004), from which the majority ofthem are fishermen and salesmen. In general, the income sources of these households are insignificantas a consequence of the technological delay and lower professional qualification. The fast and disorderedway in which territorial occupation of this coastal zone started in 80´s and it is associated to precarious infrastructures where basic sanitary facilities are absent and the public illumination is deficient. Acoastal management plan is indispensable to improve the use and occupation of the studied coastalzone and also to improve the life quality of the local population.A Vila de Ajuruteua está localizada em uma praia do litoral nordeste do estado do Pará, a 36 km dacidade de Bragança. Apresenta uma população de 392 moradores (2004), dos quais a maioria temcomo principais ocupações a pesca e o comércio. A renda familiar média é baixa, por causa do atrasotecnológico das práticas utilizadas na pesca artesanal e à baixa escolaridade e qualificação profissional.A ocupação territorial na zona costeira ocorreu de maneira rápida e desordenada, a partir dadécada de 1980, e os serviços e infra-estruturas são escassos ou inexistentes (p. ex. falta de saneamentobásico, falta de água potável, precariedade na iluminação pública, etc.). Um plano de gerenciamentocosteiro é imprescindível para melhorar o uso e a ocupação do espaço costeiro em estudo e, conseqüentemente,melhorar a qualidade de vida da população local

Use and occupation at the Ajuruteua beach (PA, Brazil)

The village of Ajuruteua is located in a beach of the northeast littoral of Para State at 36 km fromBragança city and presents a population of 392 people living there (2004), from which the majority ofthem are fishermen and salesmen. In general, the income sources of these households are insignificantas a consequence of the technological delay and lower professional qualification. The fast and disorderedway in which territorial occupation of this coastal zone started in 80´s and it is associated to precarious infrastructures where basic sanitary facilities are absent and the public illumination is deficient. Acoastal management plan is indispensable to improve the use and occupation of the studied coastalzone and also to improve the life quality of the local population.A Vila de Ajuruteua está localizada em uma praia do litoral nordeste do estado do Pará, a 36 km dacidade de Bragança. Apresenta uma população de 392 moradores (2004), dos quais a maioria temcomo principais ocupações a pesca e o comércio. A renda familiar média é baixa, por causa do atrasotecnológico das práticas utilizadas na pesca artesanal e à baixa escolaridade e qualificação profissional.A ocupação territorial na zona costeira ocorreu de maneira rápida e desordenada, a partir dadécada de 1980, e os serviços e infra-estruturas são escassos ou inexistentes (p. ex. falta de saneamentobásico, falta de água potável, precariedade na iluminação pública, etc.). Um plano de gerenciamentocosteiro é imprescindível para melhorar o uso e a ocupação do espaço costeiro em estudo e, conseqüentemente,melhorar a qualidade de vida da população local

ESTUDO MORFODINÂMICO DURANTE UMA MARÉ EQUINOCIAL DE SIZÍGIA EM UMA PRAIA DE MACROMARÉ DO LITORAL AMAZÔNICO (PRAIA DE AJURUTEUA-PA, BRASIL)

The Bragantinian coastal zone has been subjected to strong hydrodynamic processes, which continuouslyremodel its beach morphology. These energy fluctuations are more intense during the equinoctial spring tides,registered during the months of March/April and September/October. To understand the morphodynamic changesduring an equinoctial spring tide event (from 17 to 22 of March of 2003), morfodynamic studies were carried outdaily to characterize parameters such as current intensity and speed, wave break height (Hb), wave break period(T), wave break angle (αb), profile’s declivity (m), surf scaling parameter (ε), breaking coefficient (β) – and beachscarp variations. The currents were measured in the surf zone through a Sensordata SD30 current meter. Thewave break height, period and angle were measured by a graduate rule, chronometer and manual compassing,respectively. The topographic surveys were carried out in two perpendicular shoreline profiles by role andtopographic level. The analysis of these parameters showed that the studied area is, in its majority, dissipativewith a spilling type breaker, mainly in the SE sector. The observed erosive processes in the studied beach area consequence of natural causes (sometimes unknown) intensified by the human influence e.g. disorderedoccupation on dune areas and mangrove zones by edifices. The equinoctial macrotide energy was the principalfactor that contributed to the appearance of morphodynamic modifications at the Ajuruteua beach. These variationswere responsible for short-term sedimentary volume changes in the different beach sub-environments.A zona costeira bragantina está susceptível a fortes processos hidrodinâmicos que continuamente remodelama morfologia praial local. Estas flutuações de energia são mais intensas durante as marés equinociais desizígia, registradas durante os meses de março/abril e setembro/outubro, na região. Para conhecer as variaçõesmorfodinâmicas durante um destes períodos, medidas de intensidade e direção de correntes, altura da ondana rebentação (Hb), período da onda (T), ângulo de rebentação (αb), declividade do perfil (m), surf scaling parameter(ε), coeficiente de rebentação (β) e variação da escarpa, foram realizadas, diariamente, entre os dias17 e 22 de março de 2003. As correntes foram medidas na zona de surf, através de um correntômetro SensordataSD30. As alturas, períodos e ângulo de rebentação foram medidos com o auxílio de régua, cronômetro ebússola, respectivamente. Os levantamentos topográficos foram realizados em dois perfis perpendiculares àlinha de costa, com auxílio de um nível, tripé e mira falante. As análises realizadas demonstraram que a área em estudo é, em sua maioria, morfodinâmicamente dissipativa, com ondas tipo deslizante principalmente, nosetor SE. Os processos erosivos na praia em estudo são conseqüência de causas naturais, intensificadas porações antrópicas (e.g. ocupação desordenada de edificações sobre campos de dunas e área de manguezal),sendo a energia hidrodinâmica gerada pela macromaré equinocial, um fator preponderante na modificação daconfiguração morfológica da praia de Ajuruteua, durante o período em estudo. Estas alterações refletiram emtransformações morfodinâmicas a curto período que corresponderam a alterações no volume sedimentar dosdiferentes subambientes praiais