1,246 research outputs found

    Contribution of remote sensing technologies to a holistic coastal and marine environmental management framework: a review

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    Coastal and marine management require the evaluation of multiple environmental threats and issues. However, there are gaps in the necessary data and poor access or dissemination of existing data in many countries around the world. This research identifies how remote sensing can contribute to filling these gaps so that environmental agencies, such as the United Nations Environmental Programme, European Environmental Agency, and International Union for Conservation of Nature, can better implement environmental directives in a cost-e ective manner. Remote sensing (RS) techniques generally allow for uniform data collection, with common acquisition and reporting methods, across large areas. Furthermore, these datasets are sometimes open-source, mainly when governments finance satellite missions. Some of these data can be used in holistic, coastal and marine environmental management frameworks, such as the DAPSI(W)R(M) framework (Drivers–Activities–Pressures–State changes–Impacts (on Welfare)–Responses (as Measures), an updated version of Drivers–Pressures–State–Impact–Responses. The framework is a useful and holistic problem-structuring framework that can be used to assess the causes, consequences, and responses to change in the marine environment. Six broad classifications of remote data collection technologies are reviewed for their potential contribution to integrated marine management, including Satellite-based Remote Sensing, Aerial Remote Sensing, Unmanned Aerial Vehicles, Unmanned Surface Vehicles, Unmanned Underwater Vehicles, and Static Sensors. A significant outcome of this study is practical inputs into each component of the DAPSI(W)R(M) framework. The RS applications are not expected to be all-inclusive; rather, they provide insight into the current use of the framework as a foundation for developing further holistic resource technologies for management strategies in the future. A significant outcome of this research will deliver practical insights for integrated coastal and marine management and demonstrate the usefulness of RS to support the implementation of environmental goals, descriptors, targets, and policies, such as theWater Framework Directive, Marine Strategy Framework Directive, Ocean Health Index, and United Nations Sustainable Development Goals. Additionally, the opportunities and challenges of these technologies are discussed.Murray Foundation: 25.26022020info:eu-repo/semantics/publishedVersio

    Decadal sea-level changes in the Baltic Sea

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    Sustainable marine ecosystems: deep learning for water quality assessment and forecasting

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    An appropriate management of the available resources within oceans and coastal regions is vital to guarantee their sustainable development and preservation, where water quality is a key element. Leveraging on a combination of cross-disciplinary technologies including Remote Sensing (RS), Internet of Things (IoT), Big Data, cloud computing, and Artificial Intelligence (AI) is essential to attain this aim. In this paper, we review methodologies and technologies for water quality assessment that contribute to a sustainable management of marine environments. Specifically, we focus on Deep Leaning (DL) strategies for water quality estimation and forecasting. The analyzed literature is classified depending on the type of task, scenario and architecture. Moreover, several applications including coastal management and aquaculture are surveyed. Finally, we discuss open issues still to be addressed and potential research lines where transfer learning, knowledge fusion, reinforcement learning, edge computing and decision-making policies are expected to be the main involved agents.Postprint (published version

    Problemas de durabilidad de los materiales de construcción arqueológicos en ambientes acuosos y subaéreos, con aplicaciones a la restauración y conservación en Egipto y Sudán.

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    The main objective of the study was to identify and assess the conservation problems of the building materials of each case study and compare the aggressive impacts of each environment on the sustainability of the construction materials. Carefully, the construction materials (limestone, sandy limestone, sandstone, lime mortars, gypsum, hydraulic lime mortar/roman mortar) were selected from different archaeological sites with different environmental conditions in Egypt and Sudan (desert: Sahure?s pyramid and pyramids of Meroe; urban/agricultural: Nero/Ramses II Temple; coastal: Anfushi?s Necropolis; and fluvial: Abaton/Osiris Temple). To achieve this goal, field observations, analytical (X-ray diffraction, X-ray fluorescence, Raman spectroscopy, UV-Vis spectrometry), microscopic (binocular microscope, polarizing microscope and scanning electron microscope), mapping (AutoCAD, ArcMap 10.8, SeaDAS, QGIS), and physical and mechanical testing investigations were carried out. Furthermore, open-access satellite lenses were used for the detection and assessment of the archaeological sites and their risks, and, the deterioration patterns of each case study were recorded through decay mappings. Finally, to preserve the lime mortar surfaces, a newly synthesized nanomaterial of SiO2-TiO2 NPs/TEOS was applied and tested. The results showed the severity of each factor on the construction materials. In this sense, Sahure?s pyramid was affected mainly by climatic and environmental factors, earthquakes and the inner composition of the building materials. Nero/Ramses II Temple showed its susceptivity mainly from the salt attack which came from the contaminated sources of water around the temple. Water intrusion, earthquakes, storms, and heavy rains factors attacked Anfushi?s Necropolis severely. Abaton/Osiris Temple was decayed because of Nile water fluctuations impact and the inner weakness of the temple sandstones. In Sudan, the pyramids of Meroe were damaged because of the sand dunes and wind forces, in addition to the flooding risks. Finally, and concerning to the heritage conservation, the research exhibited the efficacy of the multifunctional 3% and 5% SiO2-TiO2 NPs/TEOS in the consolidation and improvement of the physical and mechanical ancient lime mortars

    The environment, diversity and activity of microbial communities in submarine freshwater springs in the Dead Sea

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    The environment,diversity and activity of microbial communities in submarine freshwater springs in the Dead Sea

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    The Dead Sea, located at the border between Jordan, Israel and the Palestinian authority is one of the most hypersaline lakes on earth. Its waters contain a total dissolved salt concentration of up to 348 g L-1, which is about 10 times higher than regular sea water. The lake is characterized by elevated concentrations of divalent cations (~2 M Mg2 and ~0.5 M Ca2 ), which, in addition to the high salinity, form an extreme environment where only highly adapted microorganisms can survive. This doctoral thesis describes the environment, diversity and activity of microbial communities in a novel ecosystem of submarine freshwater springs in the Dead Sea. These springs allow for the formation of diverse microbial mats in an otherwise hostile environment. Water chemistry analysis showed that these springs originate from the Judean Group Aquifer. However, their chemistry is altered along the subsurface flow path from the Aquifer to the Dead Sea due to microbial activity, mixing with interstitial brine in the sediment and dissolution and precipitation of minerals. Pyrosequencing of the 16S rRNA gene and community fingerprinting methods revealed that most of the spring sediment community originates from the Dead Sea sediments and not from the spring water. Using a novel salinity mini-sensor and a flume system that simulates the spring water flow into the Dead Sea it was demonstrated in the second study, that microenvironments of reduced salinity are formed in sediments and around rocks in the springs. The presence of microbial mats in these unique microenvironments led to the conclusion that one of the main drivers of the abundant microbial life is a local salinity reduction. However, as shown by flow and salinity microsensor measurements, the locally decreased salinity is unstable due to frequent fluctuations in the spring water flow. Therefore, although the microorganisms inhabiting these environments are exposed to an overall reduced salinity, they have to cope with large and rapid salinity fluctuations in the range of minutes to hours. The results of the third study showed that some of the microbial mats found in the spring area are either dominated by diatoms or unicellular cyanobacteria and are spatially separated. Growth experiments showed that the local salinity reduction is sufficient to allow for growth of these phototrophs, however, the salinity fluctuations directly affect their distribution. This could be deduced from the observation that diatoms and cyanobacteria had different in-vitro recovery rates of photosynthetic activity following rapid salinity shifts. Furthermore, the high energy demand which is expected to result from the salinity fluctuations, limits phototrophic life to shallow water depths, where enough light is available, in this case less than 10 meters. As shown in the fourth study, other microbial mats in the spring ecosystems were dominated by sulfide oxidizing bacteria (SOB), which were fueled by a flux of sulfide from the sediment below. However, sulfate reduction rates (SRR) in the spring surface sediment (<2.8 nmol cm3 day-1), were too low to account for the sulfide flux determined by in situ microsensor measurements. In fact, isotopic analysis of coexisting sulfide and sulfate in the spring water showed that the reduced sulfur compounds are instead produced along the flow path. The sulfide flux, in combination with a locally reduced salinity and O2 supply from the Dead Sea water column are the driving factors for the abundant microbial biomass of SOB encountered in the springs. Microbial mats in the Dead Sea are dominated by different types of microorganisms, ranging from different SOB genera, to cyanobacteria or diatoms. Differences in the availability of light, the mean salinity and the scale of salinity fluctuations at different spots are the main factors determining the dominating community and their spatial distribution. As reduced salinity in the spring ecosystems was shown to play an extremely important role in supporting life, it was surprising to discover that SRR in the Dead Sea sediment were higher than in the less-saline springs (up to 10 nmol cm3 day-1). While this indicates the presence of an unexpectedly active, extremely halophilic community of sulfate reducing bacteria (SRB) in the Dead Sea sediments, it also suggests that the extensive salinity fluctuations within the springs may limit the SRB populations due to the high energetic cost of osmoregulation in the dynamic system. Therefore while this thesis shows that the low salinity environment of the Dead Sea springs is advantageous for microbial life, the fluctuations within the environment bring their own set of challenges

    Underwater image restoration: super-resolution and deblurring via sparse representation and denoising by means of marine snow removal

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    Underwater imaging has been widely used as a tool in many fields, however, a major issue is the quality of the resulting images/videos. Due to the light's interaction with water and its constituents, the acquired underwater images/videos often suffer from a significant amount of scatter (blur, haze) and noise. In the light of these issues, this thesis considers problems of low-resolution, blurred and noisy underwater images and proposes several approaches to improve the quality of such images/video frames. Quantitative and qualitative experiments validate the success of proposed algorithms

    EXPORTS Measurements and Protocols for the NE Pacific Campaign

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    EXport Processes in the Ocean from Remote Sensing (EXPORTS) is a large-scale NASA-led and NSF co-funded field campaign that will provide critical information for quantifying the export and fate of upper ocean net primary production (NPP) using satellite information and state of the art technology
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