Navegando por Autor "RANIERI, Leilanhe Almeida"

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Acesso aberto (Open Access)
Avaliação experimental de métodos de armadilhas de sedimentos para determinação do transporte costeiro da praia da Romana, ilha dos Guarás (nordeste do Pará)
(2012) RANIERI, Leilanhe Almeida; EL-ROBRINI, Maâmar
The Romana Beach is ruled by waves, with an average height of 1,5 m, winds (average of 4,6 m/s) predominantly from the NE and semidiurnal meso-macrotidal (ranging from 4,3 m - march/2010; 3,4 m - august/2010). The methodology consisted of sediments samples with traps and intensity measurements of longshore currents and local winds during the months of january, march and august 2010. In the wind traps, the accumulated weight of sediments was very low, ranging from 0,02 g to 0,8 g (maximum occurred in August in the eastern sector, as well as the wind speed: 6,7 m/s). Larger quantities of sediment were collected from the eastern to the western sectors, coinciding with the prevailing wind direction (NE), whose maximum speed occurred in august (6.7 m/s in the eastern sector). In the portable traps, the minimum weight occurred in march (eastern sector, ebb tide: 0,74 g/h/m3), and the maximum in january (central sector, rising tide:139 g/h/m3). The intensity of the longitudinal currents ranged from 0,20 m/s (ebb tide) to 1,41 m/s (rising tide). It was concluded that the largest forcing of sediment transport on the beach is the flood tide current, which intensifies the longitudinal currents from the eastern to the west sectors. Secondly, the NE winds which minimize the loss of sediments on the beach, especially in the central and eastern sectors. Then the waves, maintain the direction of E-W transport because to their incidences on the coast with direction NE.
Acesso aberto (Open Access)
Morfodinâmica costeira e o uso da orla oceânica de Salinópolis (Nordeste do Pará)
(Universidade Federal do Pará, 2014-12-15) RANIERI, Leilanhe Almeida; EL-ROBRINI, Maâmar; http://lattes.cnpq.br/5707365981163429
The morphodynamic aspects related to erosion or accretion of the coastline are some of the topics analyzed in the management of coastal zones being discussed around the world in order to monitor and protect these zones. This thesis aims to analyze the behavior of the coastal morphodynamics of the Salinópolis, relating to the use of ocean margin. The study area was compartmentalized into three sectors: Western (Corvina and Maçarico beaches), Center (Farol Velho beach) and Eastern (Atalaia beach). The methodology consisted of: (a) acquisition and processing of multi-temporal images (1988-2001-2013) of the Landsat 5 TM, 7 ETM and 8 OLI; (b) application of interviews/questionnaires with bathers, (c) acquisition of field data during the rainy season (April 26th, 27th and 28th, 2013) and less rainy (045.5) prevailed at these beaches, but with the occurrence of the the longshore bar and trough state (4.7 <Ω <5.5) in the western sector. The macrotidals in the study area showed maximum height of 5.3 m (Center Sector during the less rainy season) and a minimum of 4 m in the same sector during the rainy season. The longshore currents were more intense in the eastern sector (> 0.45 m / s) during the two seasons of the year. The wave heights were also higher in the eastern sector (maximum of 1.05 m during the flood tide in the less rainy season) and wave periods were shorter (<4.5 s) in the western sector. The mean grain size obtained from sediments collected on the beaches had more frequent scale between 2.6 to 2.8 phi, indicating the predominance of fine sand. The predominant degree of sorting of sediment was 0,2 to 0,5 phi (very well sorted and well sorted), and asymmetry was positive (0.10 to 0.30) and nearly symmetrical (-0.10 to 0.10). The degree of kurtosis ranged from very platykurtic (<0.67) to very leptokurtic (1.50 to 3.00). Sediment accretion events were observed of the rainy season to less rainy season. From 07/22/1988 to 08/28/2013 (25 years) also predominated accretion, where the average linear advancement of the coastline was 190.26 m. The average linear retreat obtained for the entire study area was -42.25 m. The eroding areas are point: currencies from the beaches of Corvina and Maçarico, and Farol Velho and Atalaia. Portable traps indicated a greater quantity of sediment transported longitudinally in the less rainy season (minimum 280 g/m3: flood, west sector; maximum 1098 g/m3: ebb, east sector). In the traps applied in the swash zone, the balance of sediment entering and leaving the beaches was lower in the center sector (minimum 80 g/m3: ebb, maximum 690 g/m3: flood; less rainy season). The coastal sediment movement is derived mainly from effect of the tides, which are oriented toward the direction of the ebb and flow of the estuary crossing the coast. The data indicate the longshore transport of sediment from the Atalaia island and Sampaio River to the west sector and the beaches margins.
Acesso aberto (Open Access)
Morfodinâmica e transporte de sedimentos na praia da Romana, Ilha dos Guarás (Nordeste do Pará)
(Universidade Federal do Pará, 2011-03-03) RANIERI, Leilanhe Almeida; EL-ROBRINI, Maâmar; http://lattes.cnpq.br/5707365981163429
Coastal processes, waves, tides, currents generated and winds, model the beach face shape and contribute in the transporte and distribution of sediments on beaches. Due to the performance of these procedures, conducting experiments is severely hampered by high levels of turbulence generated by breaking waves. In sand beach, the winds gain the function of the transporte and distribution of the sediments deposited by the spreading of the waves. In Romana Beach, progradational beach ridges oriented toward W indicate the predominant sediment transport in this direction. The main objective of this study is to analyze the dynamics of this transport on the beach. The Romana barrier beach is situated at the mouth of the Pará River, an area of high hydrodynamics, is dominated by waves (RTR <3) in the less rainy period, especially during the ebb tide, and dominated by waves and tides (> 3 RTR <7) in the rainy season, mainly by flood tidal currents. The tidal regime is dominant in macrotidal beach in the rainy season (height of 4,3 m - March 2010) and in the less rainy season mesotidal (height of 3,4 m - August 2010). The incident waves at Romana Beach (on average 1,5 m in height) are primarily Northeasterly winds as they arrive on the beach in this preferential direction. The currents generated by waves propagating to the direction W, as well as the dominant tidal current on the beach: flood tidal current. The methodological procedures were applied the second beach two sets: (a) experimentation of traditional methods and (b) of alternative methods for sediment transport. The first was applied in the submerged part of the beach, through the realization of cross-sections of beach areas in West, Central and East, and measurements of speed and direction of local winds in the high tide line of each profile. The second is the application of sediment traps in the high tide line (submerged part of the beach) and in the surf zone (the submerged part of the beach) of each sector of beach, and measuring the intensity of coastal currents, the height, period and angle of incidence of waves on the submerged part of each profile. Data acquisition occurred during four field campaigns, adopting the seasonal water cycle: (a) seasonal transition to the less rainy period during the rainy season (January 2010), (b) in the middle of the rainy season, in March 2010 (equinoctial tide day) and May 2010, and during (c) less rainy season (August 2010). Throughout the seasonal cycle studied, we obtained positive final volume of sediments in Sector West (409 m3/m) and negative in the Center Sector (-306 m3/m) and the Eastern Sector (-339 m3/m). The final coefficient of variation of beach width was 9,08% in Sector West, 7,43% in the Central Sector, and 13,33% in Sector East. Note the predominance of fine sand (> 2 phi to 3 phi) well sorted (0,35 phi to < 50 phi) and very well sorted (<0,35 phi) in viii Romana Beach. Data for application of granulometric statistical parameters in the emerged part of the beach indicate the predominance of sediment transport towards E-W, it was found that the values of Mean size are growing of East Sector (minimum value found: 2,31 phi in August 2010) to West Sector (maximum value obtained: 3,37 phi in August 2010), also implying the increase in the degree of skewness in that order (Sector East to Sector West), and the degree of sorting and kurtosis increases for the West Sector to East Sector. Larger wave heights (> 1,3 m), intensity of coastal currents (> 0,3 m/s) and larger amount of sediment retained in traps wind (> 0,02 g) occurred in Sector West, also indicating the predominance sediment transport in the direction E-W. During high tide, increasing the amount of sediment retained in sediment traps used in the surf zone, especially the finer sediment and in the background traps, as well as increases the intensity of longshore currents (maximum value in West Sector in January: 1,41 m/s) of wave height (maximum of 1,62 m in the Center Sector in August) and the intensity of the winds (7,5 m/s in Sector East in August). This is due to the influence of tidal currents to be greater than the flood currents ebb in Romana Beach. It was concluded that the most significant forcing acting in the study area corresponds to the flood tidal currents (flowing and intensifying East Sector to West Sector) and, secondarily, the winds flowing in the same preferred direction, keeping the sediment supply towards W.