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AbstractExploring large volumes of geospatial data is difficult. This paper presents an approach that combines visual and computational analysis to make this process easier. This approach is based on the effective application of computational algorithms, such as the Self-Organizing Map (SOM). These are used to uncover the structure, patterns, relationships and trends in the data, and for the creation of abstractions where conventional methods may be limited. In addition, graphical representations are applied to portray extracted patterns in a visual form that allows for better understanding of the derived structures and possible geographical processes, and should facilitate knowledge construction. 相似文献
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T. Šilović Z. Ljubešić H. Mihanović G. Olujić S. Terzić Ž. Jakšić D. Viličić 《Estuarine, Coastal and Shelf Science》2011
Picoplankton distribution at the boundary zone of the southern Adriatic in May 2009 on a 75 km long shelf-continental slope transect was assessed by combining epifluorescence microscopy, flow cytometry and high-performance liquid chromatography data with hydrographic observations. The picoplankton distribution was greatly influenced by the hydrographic conditions prevailing in the southern Adriatic because of the influence of the Levantine Intermediate Water (LIW) and East Adriatic Current (EAC) forcing. Heterotrophic bacteria numerically dominated the picoplankton community through the entire transect with no significant accumulation. By contrast, picophytoplankton accumulated in the 50–75 m layer, forming a pronounced deep chlorophyll maximum. Synechococcus dominated the photosynthetic picoplankton, whereas picoeukaryotes were the least abundant. The intrusion of warm LIW observed in the layer between 100 and 350 m was followed by Prochlorococcus and Synechococcus peaks (10 × 103 cells mL−1 and 90 × 103 cells mL−1, respectively), as well as by the appearance of two Synechococcus ecotypes. Most picoeukaryotes were observed at the offshore stations, where geostrophic current calculation revealed the strongest EAC influence. A strong EAC spread over the central and eastern basin created a barrier for Prochlorococcus, whereas the picoeukaryote maxima coincided with the core of the EAC, suggesting its persistence to hydrological instabilities. 相似文献
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Damir Viličić Tarzan Legović Vera Žutić 《Aquatic Sciences - Research Across Boundaries》1989,51(1):31-46
We present a fine vertical distribution of physico-chemical parameters and phytoplankton density around the halocline (freshwater/seawater interface) in the Krka estuary on the East coast of the Adriatic Sea. Suspended matter, surfactant activity, surface active aggregates, particulate organic carbon and phaeophytin all show largest concentrations in the 20–50 cm thick interface layer. The highest concentration of chlorophyll-a is found on the upper boundary of the interface and it is a consequence of majority of viable freshwater phytoplankton cells that accumulate there. The phytoplankton accumulates selectively in the interface: larger size fractions accumulate faster than smaller ones. In particular, nanoplanakton accumulates the least. The visible interface is also populated by dead phytoplankton cells. Most of the freshwater phytoplankton dies and decomposes in the interface, as revealed by a small chlorophyll-a/phaeophytin ratio, and it represents the main source of surface active dissolved and particulate organic matter. Marine flagellates migrate and divide in the interface, while some species likeProrocentrum micans andSyracosphera sp. are also found in the upper freshwater layer. 相似文献
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Progress has been made in the Pacific region to implement the decisions taken by leaders at the Earth Summit. There has been investment in the environment and in sustainable development initiatives in the Pacific, and island countries have managed to place their concerns and special circumstances clearly on the international agenda. By the very nature of Pacific islands, Agenda 21 and its off-shoot, the Barbados Programme of Action, have influenced ocean and coastal management. However, the extent to which this has changed the fundamental approach to development in islands is less clear. While it may not be possible to determine categorically the state of implementation of Agenda 21 or how far Pacific island countries have gone down the path towards sustainable development, there are some sound indicators of change. This paper examines a number of these indicators of progress to implement Agenda 21 in the Pacific at the national, regional and international levels, and identifies some challenges for the future. 相似文献
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