GIS mapping of the Barents and Pechora Seas
Résumé
Methods of GIS mapping of environmental of the Barents and Pechora Seas under the influence of both natural and anthropogenic factors have been devised. For integrated GIS project of the Russian Arctic Seas several thematic layers have been created. These layers characterize the natural conditions of the Seas, the information on income of pollutants from different sources, possible ways of their transfer and deposition in bottom sediments. The analysis of the maps of geoecological situation of the Barents and Pechora Seas allows picking out the next geoecological regions: relatively safe, potentially dangerous and of high ecological stress. Methods of GIS mapping of sea territories for the means of estimating their ecological condition formed under the influence of both natural and anthropogenic factors are being developed. Scientists believe that this situation is due to several reasons: lack of firm evaluation criteria of sea pollution, imperfection of modern technologies and methods of ecological monitoring of the sea water areas. The analysis of the information on sea ecology that has been gathered up to now shows dissimilar data coverage of littoral and open water areas. Most of the information is provided for shelf areas of the water objects. Also there is a great diversity in the observation time and space. Retrieving methods of ecological information provide a diverse character of observations. As a result there is a sure lack of primary data and reliable information that is necessary for forming data banks and bases. For the means of producing a series of analytical and complex maps of Barents and Pechora seas with the use of GIS technologies we have analysed and worked with different data concerning natural and anthropogenic factors that determine ecological condition of the seas. Also we have developed a method of forming data base that includes maps of different scales, topics and numerous statistics. The GIS ArcInfo has been used to analyse topological thematic layers. Such layers as hydrography, sea shore, populated areas, administrative and political borders, a coastal line, morphological features of a sea bottom, etc. were created. ArcView GIS was used to create an initial database about pollution of the sea environment of the investigated seas, which should be extended and updated the later stages of the project. Information on different sources of water pollution is structured as DBF tables, containing data on the concentration of different pollutants (radioactive substances, petroleum hydrocarbons, pesticides, heavy metals) for different points of the Barents and Pechora seas areas. Further tasks (visualization, editing, combining and analysing different layers of information, modelling, creation and editing of legends and attribute tables, charts, layouts) were performed using ArcView GIS. As a result, we have developed several thematic GIS layers that characterize natural conditions of sea water areas and that provide information on income of pollutant from different sources, possible ways of their transfer and precipitation in bottom sediments. First of all is the topography of the sea bottom. The shelf of the Barents Sea is deeper than the ones of other Arctic seas. The biggest depths and the most dissected bottom relief are registered in the western part of the Barents Sea. Overdeepened, dissected with hollows and depression relief of the bottom of Barents and Pechora Seas define the possible paths of transfer and accumulation places of the pollutants. Coastal shallow waters with the depths above 50 meters occupy the most territories only in the south-east and north-west parts of the sea (Medvejinsko-Nadejdinskaya elevation). The layer containing information about geomorphologic specifics of the coast, rugged coastline and geomorphologic characteristics of linear morphostructures and morphologically similar regions, is no less important. The next thematic layer contains data concerning lithological composition of the ground of the Barents and Pechora Seas that actually differ in absorption characteristics. In specialists opinion the regions that are formed with thin dispersion material, such as the middle and border parts of the shelf, are favourable for the absorption of different pollutants. The coastal area that is usually covered with sand and other coarse ñ grained material is less influenced by the pollutants.
During the research we produced and analysed a series of analytic maps.
Origine : Fichiers produits par l'(les) auteur(s)
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