341 resultados para COASTLINE
Resumo:
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.
Resumo:
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
Resumo:
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
Resumo:
World War II profoundly impacted Florida. The military geography of the State is essential to an understanding the war. The geostrategic concerns of place and space determined that Florida would become a statewide military base. Florida’s attributes of place such as climate and topography determined its use as a military academy hosting over two million soldiers, nearly 15 percent of the GI Army, the largest force theUS ever raised. One-in-eight Floridians went into uniform. Equally,Florida’s space on the planet made it central for both defensive and offensive strategies. The Second World War was a war of movement, and Florida was a major jump off point forUSforce projection world-wide, especially of air power. Florida’s demography facilitated its use as a base camp for the assembly and engagement of this military power. In 1940, less than two percent of the US population lived in Florida, a quiet, barely populated backwater of the United States.[1] But owing to its critical place and space, over the next few years it became a 65,000 square mile training ground, supply dump, and embarkation site vital to the US war effort. Because of its place astride some of the most important sea lanes in the Atlantic World,Florida was the scene of one of the few Western Hemisphere battles of the war. The militarization ofFloridabegan long before Pearl Harbor. The pre-war buildup conformed to theUSstrategy of the war. The strategy of theUS was then (and remains today) one of forward defense: harden the frontier, then take the battle to the enemy, rather than fight them inNorth America. The policy of “Europe First,” focused the main US war effort on the defeat of Hitler’sGermany, evaluated to be the most dangerous enemy. In Florida were established the military forces requiring the longest time to develop, and most needed to defeat the Axis. Those were a naval aviation force for sea-borne hostilities, a heavy bombing force for reducing enemy industrial states, and an aerial logistics train for overseas supply of expeditionary campaigns. The unique Florida coastline made possible the seaborne invasion training demanded for USvictory. The civilian population was employed assembling mass-produced first-generation container ships, while Floridahosted casualties, Prisoners-of-War, and transient personnel moving between the Atlantic and Pacific. By the end of hostilities and the lifting of Unlimited Emergency, officially on December 31, 1946, Floridahad become a transportation nexus. Florida accommodated a return of demobilized soldiers, a migration of displaced persons, and evolved into a modern veterans’ colonia. It was instrumental in fashioning the modern US military, while remaining a center of the active National Defense establishment. Those are the themes of this work. [1] US Census of Florida 1940. Table 4 – Race, By Nativity and Sex, For the State. 14.
Resumo:
Adults of most marine benthic and demersal fish are site-attached, with the dispersal of their larval stages ensuring connectivity among populations. In this study we aimed to infer spatial and temporal variation in population connectivity and dispersal of a marine fish species, using genetic tools and comparing these with oceanographic transport. We focused on an intertidal rocky reef fish species, the shore clingfish Lepadogaster lepadogaster, along the southwest Iberian Peninsula, in 2011 and 2012. We predicted high levels of self-recruitment and distinct populations, due to short pelagic larval duration and because all its developmental stages have previously been found near adult habitats. Genetic analyses based on microsatellites countered our prediction and a biophysical dispersal model showed that oceanographic transport was a good explanation for the patterns observed. Adult sub-populations separated by up to 300 km of coastline displayed no genetic differentiation, revealing a single connected population with larvae potentially dispersing long distances over hundreds of km. Despite this, parentage analysis performed on recruits from one focal site within the Marine Park of Arrábida (Portugal), revealed self-recruitment levels of 2.5% and 7.7% in 2011 and 2012, respectively, suggesting that both long- and short-distance dispersal play an important role in the replenishment of these populations. Population differentiation and patterns of dispersal, which were highly variable between years, could be linked to the variability inherent in local oceanographic processes. Overall, our measures of connectivity based on genetic and oceanographic data highlight the relevance of long-distance dispersal in determining the degree of connectivity, even in species with short pelagic larval durations.
Resumo:
During its history, several significant earthquakes have shaken the Lower Tagus Valley (Portugal). These earthquakes were destructive; some strong earthquakes were produced by large ruptures in offshore structures located southwest of the Portuguese coastline, and other moderate earthquakes were produced by local faults. In recent years, several studies have successfully obtained strong-ground motion syntheses for the Lower Tagus Valley using the finite difference method. To confirm the velocity model of this sedimentary basin obtained from geophysical and geological data, we analysed the ambient seismic noise measurements by applying the horizontal to vertical spectral ratio (HVSR) method. This study reveals the dependence of the frequency and amplitude of the low-frequency (HVSR) peaks (0.2–2 Hz) on the sediment thickness. We have obtained the depth of the Cenozoic basement along a profile transversal to the basin by the inversion of these ratios, imposing constraints from seismic reflection, boreholes, seismic sounding and gravimetric and magnetic potentials. This technique enables us to improve the existing three-dimensional model of the Lower Tagus Valley structure. The improved model will be decisive for the improvement of strong motion predictions in the earthquake hazard analysis of this highly populated basin. The methodology discussed can be applied to any other sedimentary basin.
Resumo:
The earliest scholars were not concerned about preparing extensive investigations linking the Persian-period building remains excavated in the entire Levant together. Moreover, the research interests of scholars caused some impediments to the study of this period viz in the last decades; the Achaemenid period has been neglected by the scholars who -in turn- focused on the earlier and later periods for religious reasons. Too, while some regions have been studied abundantly, but it was not the case in other areas, which makes our knowledge is incomplete. From the explanation side, some scholars try to interpret the architectural remains from an ethnic perspective or unsubstantiated personal fancies, so their arguments were utterly lacking any objectivity. This thesis explores what are the Persian architectural and ornamental impacts on the Levantine architecture and the relations between Persian-period sites in Syria-Palestine region. Too, the architectural remains and their contents benefited us to clarify the settlement patterns in the regions being discussed. The author analyzed the ground plans of the buildings and their architectural features and ornamental motifs by conducting a descriptive, analytical, and interpretative study. He also conducted comparisons with similar buildings outside the Levant, especially in Fars to obtain a more comprehensive and systematic study, and then extracting any direct or indirect Persian influences. This has given us a better understanding of the nature of the social, political, and religious life in the entire Levant and the knowledge gap has been bridged to a satisfying extent. This study has demonstrated a few of the Achaemenid impacts, especially on the northern coastline of the Levant.
Resumo:
This thesis tries to further our understanding for why some countries today are more prosperous than others. It establishes that part of today's observed variation in several proxies such as income or gender inequality have been determined in the distant past. Chapter one shows that 450 years of (Catholic) Portuguese colonisation had a long-lasting impact in India when it comes to education and female emancipation. Furthermore I use a historical quasi-experiment that happened 250 years ago in order to show that different outcomes have different degrees of persitence over time. Educational gaps between males and females seemingly wash out a few decades after the public provision of schools. The male biased sex-ratios on the other hand stay virtually unchanged despite governmental efforts. This provides evidence that deep rooted son preferences are much harder to overcome, suggesting that a differential approach is needed to tackle sex-selective abortion and female neglect. The second chapter proposes improvements for the execution of Spatial Regression Discontinuity Designs. These suggestions are accompanied by a full-fledged spatial statistical package written in R. Chapter three introduces a quantitative economic geography model in order to study the peculiar evolution of the European urban system on its way to the Industrial Revolution. It can explain the shift of economic gravity from the Mediterranean towards the North-Sea ("little divergence"). The framework provides novel insights on the importance of agricultural trade costs and the peculiar geography of Europe with its extended coastline and dense network of navigable rivers.
Resumo:
According to various studies, the effects of climate change will be a danger to ecosystems and the population, especially in coastal areas, increasing the risk of floods. Authorities are taking action to prevent future disasters using traditional engineering solutions. These solutions can have high environmental and economic costs, fixing the coastline, increasing the salinization of aquifers, and can be subject to failure mechanisms. For this reason, studies were made to use natural engineering solutions for coastal protection, instead of traditional solutions, to achieve the UN SDGs. Coastal ecosystems have the natural ability to repair and restore themselves, increasing soil elevation, and attenuating waves. One of these solutions is the Double Dyke System, consisting of creating a salt marsh between the first dyke and a second inland. The goal is to protect the coasts and to restore ecosystems. The purpose of this study is to compare the costs of natural engineering solutions with traditional ones. It is assumed that these solutions may be more effective and less expensive in the long run. For this evaluation, a suitability analysis of the polders in the Dutch Zeeland region to assess the costs and benefits under different SLR scenarios was made. A saline intrusion model was also created to analyze the effects of a salt marsh on the aquifers. From the analyzes conducted, the implementation of the DDS turns out to be the cheapest coastal defense system in all SLR scenarios. The presence of a salt marsh could also have a positive impact on the prevention of saline intrusion in the various scenarios considered. The DDS could have a positive economic and environmental impact in the long term, reducing the investment costs for coastal defense and bringing important benefits for the protection of man and nature. Despite the results, more studies are needed on the efficiency of this defense system and on the economic evaluation of non-marketable ecosystem services.
Resumo:
Integrated Coastal Zone Management (ICZM) should be considered as one of the main components to be able to implement sustainable development. Friuli Venezia Giulia region with its 93 km of coastline is committed to investing its resources in projects aimed at studying the evolution of the coast. In this report, reference will be made to the area in front of the municipality of Grado, where the Banco della Mula di Muggia is located. Starting from previous studies and surveys, morphology of the coastal stretch between the municipality of Grado and the mouth of the Isonzo river will be reproduced through numerical modeling tools, to simulate its hydrodynamic behavior on an annual basis and also as a function of significant events such as storms, calm events or floods of the Isonzo river. The software employed will be the MIKE by DHI with in particular the implementation of "Littoral Drift" and "MIKE 21/3" Coupled models. The first to calculate net and gross longshore transport on an annual basis along a transverse profile, the latter is a modelling system for coastal application that will be used for the analysis of significant events effects. Although not primary focus of this work, there will be included an initial review of finger bars. These particular sand formations are present at the south-western border of the Banco della Mula di Muggia and may have an impact on it. This work could form the starting point of future investigations to build on the findings of this report.
Resumo:
In highly urbanized coastal lowlands, effective site characterization is crucial for assessing seismic risk. It requires a comprehensive stratigraphic analysis of the shallow subsurface, coupled with the precise assessment of the geophysical properties of buried deposits. In this context, late Quaternary paleovalley systems, shallowly buried fluvial incisions formed during the Late Pleistocene sea-level fall and filled during the Holocene sea-level rise, are crucial for understanding seismic amplification due to their soft sediment infill and sharp lithologic contrasts. In this research, we conducted high-resolution stratigraphic analyses of two regions, the Pescara and Manfredonia areas along the Adriatic coastline of Italy, to delineate the geometries and facies architecture of two paleovalley systems. Furthermore, we carried out geophysical investigations to characterize the study areas and perform seismic response analyses. We tested the microtremor-based horizontal-to-vertical spectral ratio as a mapping tool to reconstruct the buried paleovalley geometries. We evaluated the relationship between geological and geophysical data and identified the stratigraphic surfaces responsible for the observed resonances. To perform seismic response analysis of the Pescara paleovalley system, we integrated the stratigraphic framework with microtremor and shear wave velocity measurements. The seismic response analysis highlights strong seismic amplifications in frequency ranges that can interact with a wide variety of building types. Additionally, we explored the applicability of artificial intelligence in performing facies analysis from borehole images. We used a robust dataset of high-resolution digital images from continuous sediment cores of Holocene age to outline a novel, deep-learning-based approach for performing automatic semantic segmentation directly on core images, leveraging the power of convolutional neural networks. We propose an automated model to rapidly characterize sediment cores, reproducing the sedimentologist's interpretation, and providing guidance for stratigraphic correlation and subsurface reconstructions.