Lidriana de Souza Pinheiro

Trace metal concentrations in tropical mangrove sediments, NE Brazil

Sediment cores were taken from the mangroves of the Coreaú River estuary off the northeast coast of Brazil. They were analyzed for grain size, CaCO3, organic matter, and trace metal (Cd, Pb, Zn, Cu, Al, and Fe) contents. Mud texture was the predominant texture. Levels of trace metals in surface sediments indicated strong influence of anthropogenic processes, and diagenetic processes controlled the trace metal enrichment of core sediments of this estuary. The positive relationships between trace metals and Al and Fe indicate that Cu, Zn, Pb, and Cd concentrations are associated mainly with Al and Fe oxy-hydroxides and have natural sources.

The Beaches of Ceará

The coastal zone of Ceara State, in Northeastern Brazil, extends for 573 km in a SE- NW direction. It is predominantly composed of sandy sediments of Upper Tertiary-Quaternary age with several generations of Pleistocene transgressive dunes, together with beaches, estuarine plains and localized occurrences of cliffs. The Precambrian rocks also occur on some beaches. The climate is semi-arid tropical and the rivers only flow into the sea during the rainy season. The dunes, beaches and estuary margins have experienced serious problems derived from the loss of sand material that have been taken to be used in coastal engineering, edifications and natural environmental degradation processes concerned to the sediment budget. In this context, this chapter focuses the description of the morphodynamics characteristics of the beaches of Ceara State, highlighting the factors controlling spatial and temporal processes, as well as discussing the impacts, potential uses and limitations of these areas. The results indicate that today this coastal erosion, either natural or induced by man, is perceived as the most significant threat to maintaining services in areas that depend upon tourism, traditional economic activities, housing and other pertinent uses of the beaches. It has been pointed out that the natural and human impacts represent the main and outstanding challenges for dwellers and the coastal managers who need to find out the new ways of living and occupation, includes redesigning the processes of house constructions and keeping up with minimizing the impacts. Then, the main actions that deal with the use and abuse of this littoral are discussed in this chapter. The environmental problems have to be strictly controlled, particularly stabilization of the mobile dune and preventing development of cliffs and headlands.

Piauí Beach Systems

Coastal plain of Piaui State is composed by variety of geomorphological distinct features including low sandy beaches, sandstone reefs, estuarine and marine complexes systems, coastal lagoons, tidal plains, sandy spits, extensive sand dunes, deltaic plain and others features. These features result from the combined action of waves, coastal currents, fluvial action, sea level variation and climatic and meteorological factors. Piaui State is located in the northeast Brazil covering an area of 251,578 km2 with a population of 3,118,360 (IBGE 2010). The territory lies between 02°44′ and 10°55′S and extends for 900 km in a north-south direction, but has a coastline of only 66 km in the north aligned in an east-west direction located between Ceara and Maranhao States. The range of geo-environmental conditions represents most of the Brazilian biomes. This chapter presents the coastal and morphological dynamics and the features of Piaui Beach Systems. It discusses the variables that control the active coastal processes, with the primary objective to understand the relationship between these variables and human interventions.

DISTRIBUIÇÃO DAS FORMAS DE FUNDO E PADRÕES SEDIMENTARES NO PORTO DO MUCURIPE, FORTALEZA-CEARÁ

A ponta do Mucuripe apresenta desde a decada de 1930 constantes alteracoes morfologicas nos setores emersos e submersos. A area de estudo e o setor submarino adjacente ao porto do Mucuripe em Fortaleza-CE, no qual foi realizada uma analise das repostas acusticas do substrato associado a constantes intervencoes para o gerenciamento portuario. Classificou-se a morfologia submersa do porto do Mucuripe levando em consideracao a visao integrada das condicionantes ambientais (processos, formas e intervencao antropica) na construcao da paisagem submarina. Foi utilizada sismica de alta resolucao, sonografia, e compilacao de dados sedimentologicos. As respostas acusticas produto dos padroes de sedimentacao e das formas submersas constituiram as ecofacies. A ecofacies I esta associada a substratos lamosos (principalmente lama fluida) com refletores em subsuperficie, relacionado principalmente a bacia de evolucao e canal de acesso portuario (areas abrigadas pelo molhe do Tita). A ecofacies II possui camadas em subfundo bem compactas, onde nao se observa nitidamente os refletores, esta associada a evolucao da ecofacie I e consequente compactacao, tambem localizada em setores abrigados. Estas duas ecofacies apresentam o padrao morfologico de fundo plano como dominante, sendo interrompido apenas nos setores com marcas de dragagens – os canaliculos. A ecofacies III apresenta alto coeficiente de reflexao, substrato relacionado a sand ripples e dunas subaquosas, associado predominantemente aos setores desabrigados do molhe. A ecofacies IV esta associada a substratos rochosos e possui elevado backscattering, localiza-se no setor sul adjacente ao Pier. Como padroes morfologicos destacam-se as feicoes produto das dragagens no canal de acesso portuario e bacia de evolucao – taludes, canaliculos e monticulos. Evidenciou-se o contraste granulometrico entre o canal e as adjacencias, sendo que no setor desabrigado e observada a predominância de fundo arenoso com consequente presenca de micro-feicoes – sand ripples e macro-feicoes – banco/dunas e na area abrigada o predominio de sedimentos finos. Foi observado um objeto a semelhanca de uma embarcacao de pequeno porte naufragada nas proximidades do Pier. A presenca de lama fluida, principalmente, dentro do canal no setor da bacia de evolucao se deve ao aporte de sedimentos finos (<0,062mm) que se deposita devido a baixa hidrodinâmica (efeito “sombra” do molhe do Tita). O assoreamento constante no setor abrigado impoe o mapeamento dos setores de lama fluida. Este fato se torna de fundamental importância para gerenciar os locais em que necessitam de dragagens de manutencao, para garantir profundidades seguras para a mobilidade naval.

Processo de uso e ocupação no estuário do rio Acaraú – Ceará e áreas adjacentes, uma análise multitemporal das formas de uso

Os sucessivos ciclos economicos que se desenvolveram no litoral cearense durante o seculo XX e nas primeiras decadas do seculo atual, baseiam-se na extracao de sal marinho, na pesca artesanal e na cadeia economica associada a pesca da lagosta. Recentemente tem se destacado outras atividades como a carcinicultura, o turismo, a expansao imobiliaria nas areas proximas a faixa praial e mesmo nos tabuleiros costeiros, alem da implantacao dos grandes parques de aerogeradores. Estas atividades no municipio de Acarau – CE, so demostram a importância estrategica desse espaco. Por isso a importancia de conhecer a evolucao espacial e temporal para availiar se estas atividades sao ou serao, ambientalmente sustentaveis. O objetivo deste trabalho foi demonstrar a evolucao deste ambiente e identificar as principais formas atuais de uso da terra a partir de mapas tematicos da area utilizando tecnicas de geoprocessamento a partir de imagens orbitais dsponiveis dos anos 1985, 2001 e 2014.

Application of Geo-ecological and Thematic Mapping to the Analysis of Estuarine Environments in Northeastern Brazil

Over the past few decades, the occupation and exploitation of the natural resources found in Brazilian estuaries have increasingly impacted the ecological integrity of these systems, altering their internal dynamics and the daily life of local communities. In this context, this chapter focuses on a conservation unit located on the western coast of the northeastern Brazilian state of Ceara, centered on the estuary of the Mundau River. The research included the diagnosis of the water quality of the study area, based on the analysis of pH, salinity, dissolved oxygen, temperature, and transparency, and the identification and mapping of the geo-ecological units of the study area. Data were collected in the field using digital multianalyzers every 3 months between April 2011 and December 2011, during the spring tide (low and high tide), and the maps were produced in ArcGIS 9.3. The results indicate that the water quality of the study area complied with Brazilian sanitary norms with only localized abnormalities, which do not appear to reflect any major disequilibrium of the estuarine system at the present time.

Interferências de barramentos no regime hidrológico do estuário do rio Catú-Ceará-Nordeste do Brasil

The Catu River estuary lies 26 km SW of Fortaleza in Aquiraz municipality. This study aims to evaluate the small and medium barrier impacts in fresh water inputs and effects on the morphological evolution and environmental fragility of the estuary system. The main superficial flow interventions have been chosen and analyzed as well as the margins use and occupation from 1990 to 2004. The impacts focu- sed in the barrier spilling were simulated through semi-empirical equation models, once there was no fluviometry monitoring stations. The over dimension of the Catu river spill wall, in 993, gave rise to flow relentless in rainy seasons for volumes less than 1 m 3 .s -1 favoring the mouth silting, estuary area shortage and mangrove decreasing. Afterwards, the wall resizing increased flow rate to 7 m 3 .s -1 due to flash flood in upstream areas at rainy season, allowing channel clearing and water oxygenation. The public dam Catu-Cinzento, in the river backland, decreases in 30% the lake water input and in the estu- ary. This caused the estuary water volume shortage from 8.507 m 3 to 2.045 m 3 under the same climatic