Mapeamento de recifes no Rio Grande do Norte: Touros e Macau/RN

Studies on the Brazilian continental shelf were developed between Touros and Macau-RN (NE Brazil) with the aim to mapping carbonate buildups, and especially, reef ecosystems. Remote sensing, submarine movies, bathymetric survey and diving were the methods used. This paper will focus on three main aspects of the Rio Grande do Norte reefs: 1) characterization of the coral fauna; 2) the classification and, 3) the distribution of the main northriograndense carbonate buildups. Reefs environments are found predominantly on the inner shelf adjacent to Touros, at depths shallower than 10 m. These reefs generally show NW-SE orientation parallel to the coastline and constitute groupings of knolls and patch reefs. A prominent carbonate buildup, where the corals are almost absents and algae incrustation is thin, occurs in average depths of 25 m, along the northern part of Rio Grande do Norte State and is classified as sandstone bank. Others sandstone banks, with smaller lengths and heights were mapped around 10 m depth. They should be related to an ancient coastline; however the corresponding litostratigraphic unit was not defined. This work is a contribution to the mapping of coral reef, in particular, and carbonate buildups, in general, on the Rio Grande do Norte coast

Caracterização hidrodinâmica e morfo-sedimentar do estuário Potengi e áreas adjascentes: subsídios para controle e recuperação ambiental no caso de derrames de hidrocarboneto

This study presents the Environmental Sensibility Mapping to oil spillings on the Potengi estuary - RN and neighboring coastline through remote sensing data, collecting, treatment and integration of the geomorphologic, oceanographic (temperature, salinity, density, direction and intensity), meteorological (wind speed and direction) and high resolution seismic (bathymetry and sonography) data. The Potengi river estuary is located on the eastern coastline of the Rio Grande do Norte State, being inserted in the geological context for the coastal Pernambuco-Paraíba basin and spreading over 18 km; it shelters the Natal harbor zone and an oil terminal, centralizing, therefore, important oil transport operations that can cause accidental spillings. Under the oceanographic point of view, the Potengi estuary is characterized by the absence of any expressive thermic stratification, being classified as partially mixed, B type according to Pritchard (1955), and 2 type in conformity to the stratification-circulation diagram by Hansen & Rattray (1966). Two main wind systems are responsable for the formation of wave sets that occur in the area. The dynamic tide presents, in the Natal Harbor, mean amplitude in spring and quadrature tides, with around 2.8 and 2m, respectively. The mechanism of saline tide mixing was defined through the salinity which is the main parameter for the identification of this mechanism. Important variations of the salinity mean values (36.32 psu), temperature (28.11ºC) and density (22.96 kg/m3) in the estuarine waters presented features belonging to low latitude regions. The water temperature follows the air temperature variations, in the region, with expressive daily amplitudes. In this study, the identification of the estuarine bed morphology through bathymetric and sonographic analysis, had the purpose to evaluate the influence of the superficial and bottom currents for the bottom shaping. In this way, the use of the side scan sonar showed, to be very useful in the identification of the bottom morphology and its relationship with the predominant action of the tidal currents in the Potengi estuary. Besides, it showed how the sonograms can be a support to the comparison of the several patterns derived from the local hydrodynamic variations. The holocene sediments, which fill the estuarine channel, are predominantly sandy, varying from selected, sometimes silty. The sedimentation is controlled by the environmental hydrodynamic conditions, being recognized two important textural facies: Muddy Facies and Sandy Facies. The distribution of these textural facies apparently oscillates owing to the tidal cycle and flow intensity. Each one of the above mentioned data was integrated in a Geographic Information System (GIS), from which was produced the Environmental Sensibility Map to oil spillings with Coastal Sensibility Index (CSI) to the Potengi estuary. The integrated analysis of these data is essential to oil spilling contingency plans, in order to reduce the spilling environmental consequences and to make efficient the endeavours of contention and cleaning up/removal on the Natal Harbor. This study has the aim to collaborate for the increase of informations about the estuarine environment and contribute to a better management of the question: environment/polluting loads

A vilegiatura marítima e a urbanização em Tibau/RN

This research aims the analysis of the urbanization process that has taken place in the coastal city of Tibau/RN in the period comprising 1980-2012, due to the (re) production of space to consumption of leisure and recreation, through the so called practice of Maritime Villeggiatura. Such practice exists so that people settle temporarily on the beach as a second home, interfering in the Regulation of the land use as well as in the urban planning of Tibau, promoting urbanization based in the logic of leisure, with enormous capacity for appropriation and space consumption. The practice of Maritime Villeggiatura in Tibau began in the late nineteenth century, becoming more relevant in the 1980s, when the practice became fashionable for the citizens of Mossoró City, in view of their economic strength, and consumption power to invest in this type of domicile. Tibau has become a great depository of second homes for leisure practice, which contributed even to the city administrative and political emancipation in 1997. The intensification of Real Estate activities, expanding second homes along the coast, results in the urbanization of Tibau territory with the assistance of Local Government, whom was interested in entering Tibau on the State tourism routes. The used methodology comprised literature review, data collection and local observation. Questionnaires were applied in the form of interviews to the villeggiaturistas, local residents, business and trade services local companies, a local agricultural firm named Agricultura Famosa Ltda., Municipal government and the Association of Senior Citizens of the municipality of Tibau. A photographic record was made to visualize the urbanization evolution of Tibau. It has also been taken georeference measures of the area object of study in this research, in order to analyze the use and occupation of the territory by urban and social agents villeggiaturistas and residents. The conclusion is that the urbanization process that has been taken in Tibau occurred along the coast shore, with low population density, and therefore creating difficulties to governance of the Municipal government. Real Estate Sector has been promoting the value increase of urban land in order to fragment the space with private condominiums segregating local resident population to outlying areas of the city, away from the coastline and lacking infrastructure and basic urban services

Análise geoambiental da plataforma continental Rasa Equatorial, por meio de sensoriamento remoto e dados sedimentológicos: parrachos de Rio do Fogo-RN, Brasil

In the shallow continental shelf in Northeastern Rio Grande do Norte - Brazil, important underwater geomorphological features can be found 6km from the coastline. They are coral reefs, locally known as “parrachos”. The present study aims to characterize and analyze the geomorphological feature as well as the ones of the benthic surface, and the distribution of biogenic sediments found in parrachos at Rio do Fogo and associated shallow platforms, by using remote sensing products and in situ data collections. This was made possible due to sedimentological, bathymetric and geomorphological maps elaborated from composite bands of images from the satellite sensors ETM+/Landsat-7, OLI/Landsat-8, MS/GeoEye and PAN/WordView-1, and analysis of bottom sediments samples. These maps were analyzed, integrally interpreted and validated in fieldwork, thus permitting the generation of a new geomorphological zoning of the shallow shelf in study and a geoenvironmental map of the Parrachos in Rio do Fogo. The images used were subject to Digital Image Processing techniques. All obtained data and information were stored in a Geographic Information System (GIS) and can become available to the scientific community. This shallow platform has a carbonate bottom composed mostly by algae. Collected and analyzed sediment samples can be classified as biogenic carbonatic sands, as they are composed 75% by calcareous algae, according to the found samples. The most abundant classes are green algae, red algae, nonbiogenic sediments (mineral grains), ancient algae and molluscs. At the parrachos the following was mapped: Barreta Channel, intertidal reefs, submerged reefs, the spur and grooves, the pools, the sandy bank, the bank of algae, sea grass, submerged roads and Rio do Fogo Channel. This work presents new information about geomorphology and evolution in the study area, and will be guiding future decision making in the handling and environmental management of the region

Análise paramétrica da estabilidade de falésias e estudo de caso da Ponta do Pirambu em Tibau do Sul/RN

The coastline from Rio Grande do Norte state is characterized for the presence of dunes and cliffs. The latter consist of slopes with height up to 40 meters and inclinations ranging from 30° to 90° wich horizontal. Thus, this dissertation had as objective the evaluation of the stability of cliff from Ponta do Pirambu in Tibau do Sul/RN, and the realization of a parametric study on the stability of a homogeneous cliff considering as variables the material's cohesion, the cliff height and the slope inclination. The study in Ponta do Pirambu considered yet the possibility of the existence of a colluvial cover with thickness ranging from 0.50 to 5.00 meters. The analyzes were performed by Bishop method, using GEO5 software. In parametric analysis were produced graphics that relate height cliff with the inclination, to safety factors equals to 1.00 and 1.50; besides graphics where it is possible easily get the lowest safety factor as from the cohesion, cliff height and its inclination. It was concluded that these graphs are very useful to preliminary analyzes, for the definition of critical areas in risk mappings in areas of cliffs and for determination of an equation for obtaining the lowest safety factor function of the strength parameters and of slope geometry. Regarding the cliff from Ponta do Pirambu, the results showed that the cliff is subject to superficial landslides located in the points where may there be the presence of colluvium with thicknesses greater than two meters. However, the cliff remains stable presenting the global safety factor equal or superior to 2.50 in the saturated condition.

Transporte longitudinal de sedimento na zona costeira de Natal/RN

The longshore sediment transport (LST) is determinant for the occurrence of morphological changes in coastal environments. Understanding their movement mechanisms and transport is an essential source of information for the project design and coastal management plans. This study aims to characterize, initially, the active hydrodynamic circulation in the study area, comprised of four beach sectors from the south coast of Natal, assessing the average annual LST obtained through three proven equations (CERC, Kamphuis and Bayram et al.), defining the best formulation for the study area in question, and analyze the seasonal variability and the decadal transport evolution. The coastal area selected for this work constitutes one of the main tourist corridors in the city, but has suffered serious damage resulting from associated effects of hydrodynamic forcings and their disorderly occupation. As a tool was used the Coastal Modelling System of Brazil (SMC-Brazil), which presents integrated a series of numerical models and a database, properly calibrated and validated for use in developing projects along the Brazilian coastline. The LST rates were obtained for 15 beach profiles distributed throughout the study area. Their extensions take into account the depth of closure calculated by Harllermeier equation, and regarding the physical properties of the sediment, typical values of sandy beaches were adopted, except for the average diameter, which was calculated through an optimization algorithm based on equilibrium profile formulation proposed by Dean. Overall, the results showed an intensification of hydrodynamic forcings under extreme sea wave conditions, especially along the headlands exist in the region. Among the analyzed equations, Bayram et al. was the most suitable for this type of application, with a predominant transport in the south-north direction and the highest rates within the order of 700.000 m3 /year to 2.000.000 m3 /year. The seasonal analysis also indicated a longitudinal transport predominance in the south to north, with the highest rates associated with the fall and winter seasons. In these periods are observed erosive beach states, which indicate a direct relationship between the sediment dynamics and the occurrence of more energetic sea states. Regarding the decadal evolution of transportation, it was found a decrease in transport rate from the 50’s to the 70’s, followed by an increase until the 2000’s, coinciding with the beginning of urbanization process in some stretches of the studied coastline.

Uso e ocupação do solo e a transformação da paisagem na faixa litorânea da Via Costeira, município de Natal/RN

The coastal area of the city of Natal due to its location and natural potentialities has been an area where we have experienced big changes in its environment, at the expense of several forms of use and human occupation. On the coast of Via Costeira beach the process of use and land occupation was structured at the end of 1970s and early 1980s, as a result of the government policy which has developmental essence, based on the settlement of plenty big enterprises by the Parque das Dunas/Via Costeira Project. This project was created to install in Natal, capital of the state, infrastructure equipment on this stretch of coastline consisted of dune fields and many parts of ecosystems which have high natural relevance and fragility that used to present a semi-isolation in the urban city, for the development of tourist activities, which is considered as a viable economic solution capable of setting right serious socioeconomic problems that had persisted there. According to what was said so far, this study aimed to analyze the forms of use and land occupation besides the change of the landscape along the Via Costeira coast in the city of Natal/RN. These changes often take place without considering the complexity and fragility of natural ecosystems involved. The geoenvironmental study was based on the geosystemic theory, thus It was possible to analyze the human interventions in the superficial aspects of landscapes holistically. The practical procedures were contemplated with literature searches, followed by field work where were fulfilled the recognition and general characterization of the area in order to investigate and analyze the main types of land occupation and its use that have taken place there since big buildings began to come out, being supported by the legislation whose laws are about protection and conservation of coastal natural resources. The research also includes the identification and evaluation of the main types of negative impacts caused due to different forms of use that induce environmental and social conflicts nearby this shore. Thus, It was carried out a spatial and multitemporal analysis from orthophotos, aerial photographs and others taken during the field work besides satellite images too. The information which is taken out from these instruments was used to draw maps related to land occupation, spatial impacts and other thematic maps. We worked on a hypothesis that the implementation of mega enterprises on Via Costeira and many different forms of intensified use by human actions, has not considered the natural aspects and restrictions of use in this area, these ones would be the main factors that brought on the suppression and degradation in this environment and consequently the transformation of the natural landscape.

Terrenos de marinha: terras públicas com função social? um estudo da orla marítima de natal

This work has as its theme the social function of terrenos de marinha. Theresearch universe is the terrenos de marinha of Natal coastline, focusing on thefulfillment of its social function. Prescribed by law since the colonial period with thepurpose of protecting the coast and free movement of people and goods, theywere swathes of land not available to private use by individuals. With the transitionfrom the allotments system to the purchase and sale, regard to land access,crystallized with the creation of the Land Law in the nineteenth century, the land isheld as merchandise and terrenos de marinha, following this logic, also acquireexchange value and become capable of enjoyment by private individuals, with thecondition of tax payments to the state. This is seen until the twentieth century,when in 1988, primarily because of the Federal Constitution promulgation, begins anew cycle when is possible to use on terrenos de marinha the principle of thesocial function of property. From this perspective this study aims to identify thesocial function of terrenos de marinha in Natal, focusing on the public destinationand the use value of the city coastline. To this end, it was made a data collection inthe on-line information system of the Federal Heritage Department of Rio Grandedo Norte (SPU / RN) and in the terrenos de marinha areas, in order to find out ifthey had public or private use, or if they were empty lots, as well as if thepopulation access to the shore exist. Interviews with managers of the SPU weremade. The empirical study showed that the social function of terrenos de marinhain the city of Natal still didn´t happen, considering the constant existence of vacantlots in their areas, the lack of access in significant portions of the coastline and thereduced areas directed to common use along the coastline, minimizing its potentialof enjoyment by the population. It concludes by pointing to the existence of a newtransition phase on the terrenos de marinha, in witch, gradually, come up lawprovisions in the legal system and public policies to expand the purely taxcollection function attributed to this land for two centuries. In this direction, thesocial function of terrenos de marinha is embodied in concomitant adjustment ofthe tax collection function and the rescue of coastline use value, national heritageand a place for sociability and social relations development

Atividade antioxidante de fucanas e galactanas extraídas de algas marinhas

Studies made with polysaccharides of seaweed have demonstrated that these present important biological and pharmacological activities. These composites had presented "scavenging" activity of free radicals, which is important in the mediation of the inflammatory process and in the pathology of diverse disease. Recently, this "scavenging" property has taken some researches to evaluate the antioxidant capacity from various polysaccharides. Considering the limited research with polysaccharides and knowing its largely employed by the pharmaceutical and foodstuffs industries, we have objective to verify the actions from fucans and galactans as antioxidants. The fucans are found in brown seaweed and the galactans (carrageenans) in red seaweed. The fucans were obtained from seaweed Padina gymnospora (F0.5 e F1.1 fractions), common to our coastline and one another fucan, fucoidan, was of origin commercial and extracted from seaweed Fucus vesiculosus. The λ, κ e ι carrageenans were also of origin commercial. The antioxidant activities were tested in superoxide and hydroxyl systems to generated free radicals and for the inhibition of the lipid peroxidation. The results obtained to inhibition of formation the superoxide radicals demonstrated that all polysaccharides presented scavenging activity of superoxide radicals. The fucoidan, F0.5 and F1.1 fractions presented IC50 of 0.058; 0.243 and 0.243 mg/mL, respectively, while IC50 of the λ, κ and ι carrageenans were 0.046; 0.112 and 0.332 mg/mL, respectively. The results to inhibition of formation the hydroxyl radicals demonstrated that all sample had low effect in the inhibition of the formation of these radicals, except the F0.5. For these radicals the IC50 were 0.157 and 0.353 mg/mL to the fucoidan and F1.1, respectively and 0.357; 0.335 and 0.281 mg/mL to λ, κ and ι carrageenans, respectively. All the samples were capacity to inhibition the peroxidation, it present the IC50 of 1.250; 2.753 and 2.341 mg/mL to fucoidan, F0.5 and F1.1, respectively. Already the λ, κ and ι carrageenans presented the IC50 of 2.697; 0.323 and 0.830 mg/mL, respectively. With these findings, we conclude that polysaccharides used in this study presented activity antioxidant, and that fucoidan and the λ carrageenan show a significant "scavenging" activity for the radicals superoxide and the κ carrageenan a significant inhibitory activity for the lipid peroxidation

Avaliação de concretos reforçados por confinamento com manta de fibra de vidro estrutural e pré-impreganada

Due to the occurrence of diseases in the use of structural reinforcements in composites, with presentation of concrete blanket detachment, has been identified the need to evaluate the performance of concrete reinforced with glass fiber. This study aims to evaluate these concretes by means of testing methodologies, using concrete with low resistance with structural reinforcement for confinement by preimpregnated glass fiber and traditional fiberglass blanket. The first stage of work was the development of methodologies for analysis, opting for four types, such as the acoustic survey, strength to compressive, the pull-off and ultrasound. Next, tests were carried out using the four selected methodologies in 30 of proof-of-specimens by 5x10 cm, 15 were reinforced with the traditional fiberglass blanket with 5specimens exposed to test a marine environment of marine coastline of Natal-RN and 15 were reinforced with a pre-impregnated glass fiber blanket, as well as 5specimens exposed to a test environment of the marine coastline of Natal-RN. After conducting the acoustic survey, it has been verified a lack of delaminating and air bubbles in the samples, confirming the absence of gross shortcomings in the implementation of the ribs both the traditional fiberglass blanket and in the preimpregnated fiber glass blanket. After carrying out methods of pull-off and compressive strengthening test it was observed that the reinforced proof-bodies with pre-impregnated glass blanket showed maximum stresses higher than the traditional fiberglass blanket; consequently a greater grip with the formation of a smaller area of . fracture, unlike traditional glass mat, which showed lower maximum stresses, with a greater area of fracture. It was also found that the traditional fiberglass blanket presented detachment of blanket-concrete interface, unlike the pre-impregnated fiberglass blanket, which showed a better grip on the blanket-concrete interface. In the trial of ultrasound there was no presence of cracks in the blanket-concrete interface, yielding to both blankets good compactness of the concrete. At the end of this work, they were developed and proposed two methods of testing for evaluation of reinforced concrete structures with composites, for standardization, the acoustic survey and pull-off

Contribuição da Geodésia ao monitoramento costeiro do Litoral Setentrional do Rio Grande do Norte, área de influência da indústria petrolífera

The general objective of this thesis has been seasonal monitoring (quarterly time scale) of coastal and estuarine areas of a section of the Northern Coast of Rio Grande do Norte, Brazil, environmentally sensitive and with intense sediment erosion in the oil activities to underpin the implementation of projects for containment of erosion and mitigate the impacts of coastal dynamics. In order to achieve the general objective, the work was done systematically in three stages which consisted the specific objectives. The first stage was the implementation of geodetic reference infrastructure for carrying out the geodetic survey of the study area. This process included the implementation of RGLS (Northern Coast of the RN GPS Network), consisting of stations with geodetic coordinates and orthometric heights of precision; positioning of Benchmarks and evaluation of the gravimetric geoid available, for use in GPS altimetry of precision; and development of software for GPS altimetry of precision. The second stage was the development and improvement of methodologies for collection, processing, representation, integration and analysis of CoastLine (CL) and Digital Elevation Models (DEM) obtained by geodetic positioning techniques. As part of this stage have been made since, the choice of equipment and positioning methods to be used, depending on the required precision and structure implanted, and the definition of the LC indicator and of the geodesic references best suited, to coastal monitoring of precision. The third step was the seasonal geodesic monitoring of the study area. It was defined the execution times of the geodetic surveys by analyzing the pattern of sediment dynamics of the study area; the performing of surveys in order to calculate and locate areas and volumes of erosion and accretion (sandy and volumetric sedimentary balance) occurred on CL and on the beaches and islands surfaces throughout the year, and study of correlations between the measured variations (in area and volume) between each survey and the action of the coastal dynamic agents. The results allowed an integrated study of spatial and temporal interrelationships of the causes and consequences of intensive coastal processes operating in the area, especially to the measurement of variability of erosion, transport, balance and supply sedimentary over the annual cycle of construction and destruction of beaches. In the analysis of the results, it was possible to identify the causes and consequences of severe coastal erosion occurred on beaches exposed, to analyze the recovery of beaches and the accretion occurring in tidal inlets and estuaries. From the optics of seasonal variations in the CL, human interventions to erosion contention have been proposed with the aim of restoring the previous situation of the beaches in the process of erosion.

Monitoramento da morfologia costeira em setores da bacia potiguar sob influência da indústria petrolífera utilizando geodésia de alta precisão e laser escâner terrestre

The objective of this Doctoral Thesis was monitoring, in trimestral scale, the coastal morphology of the Northeastern coast sections of Rio Grande do Norte State, in Brazil, which is an area of Potiguar Basin influenced by the oil industry activities. The studied sections compose coastal areas with intense sedimentary erosion and high environmental sensitivity to the oil spill. In order to achieve the general objective of this study, the work has been systematized in four steps. The first one refers to the evaluation of the geomorphological data acquisition methodologies used on Digital Elevation Model (DEM) of sandy beaches. The data has been obtained from Soledade beach, located on the Northeastern coast of Rio Grande Norte. The second step has been centered on the increasing of the reference geodetic infrastructure to accomplish the geodetic survey of the studied area by implanting a station in Corta Cachorro Barrier Island and by conducting monitoring geodetic surveys to understand the beach system based on the Coastline (CL) and on DEM multitemporal analysis. The third phase has been related to the usage of the methodology developed by Santos; Amaro (2011) and Santos et al. (2012) for the surveying, processing, representation, integration and analysis of Coastlines from sandy coast, which have been obtained through geodetic techniques of positioning, morphological change analysis and sediment transport. The fourth stage represents the innovation of surveys in coastal environment by using the Terrestrial Laser Scanning (TLS), based on Light Detection and Ranging (LiDAR), to evaluate a highly eroded section on Soledade beach where the oil industry structures are located. The evaluation has been achieved through high-precision DEM and accuracy during the modeling of the coast morphology changes. The result analysis of the integrated study about the spatial and temporal interrelations of the intense coastal processes in areas of building cycles and destruction of beaches has allowed identifying the causes and consequences of the intense coastal erosion in exposed beach sections and in barrier islands

Estrutura da população de Coleodactylus natalensis Freire, 1999 (Squamata: Sphaerodactylidae) no Parque Estadual Dunas de Natal, Rio Grande do Norte, Brasil

Coleodactylus natalensis Freire, 1999, an endemic species of Atlantic Forest fragments around the Natal municipality, Rio Grande do Norte State, Brazil, has as type locality the Parque Estadual Dunas de Natal (05º48 S to 05º53 S and 35º09 W to 35º12 W), one of the largest restinga (herb and shrub association on sand dunes along the Brazilian coastline) associate fragment, surrounded by urban zone, placed on setentrional Atlantic Forest limits. We made estimates on populational density, spatial distribution, habitat and microhabitat preferences and feeding ecological aspects like sazonal and sexual variations on diet, prey electivities and niche breadth. We randomly sampled ninety-six 50m2 quadrants in each of the four habitats identified in the study area. Were collected 49 specimens and their stomach contents were analyzed; prey items found were correlated with leaf-litter invertebrates from habitat samples. We found a 98,5 ± 75,5 individuals/ha density, in grouped distribution pattern on densest habitats and random distribution on others habitats. This species lives mostly on leaf-litter in forest habitats, in higher humidity points, with lower temperatures, deeper leaf litter and lower sea level elevations than the randomly chosen points in the study area. Isopoda and Aranae were the most important prey categories in numeric, frequency and volumetric terms. Niche breadth has an intermediate value and was variable in sexual and in habitat terms. There was no correlation between morfometric measures and prey size on diet. The C. natalensis population studied seems to be diet opportunist, although selects larger prey items. The Parque Estadual das Dunas do Natal has several indications of anthropic pressure from the surrounding urban area that may affects the local C. natalensis population. Thus, the fragility of this species calls for urgent conservation efforts