Natural and anthropogenic dynamics of the floodplain landscapes near Tomsk

The study of the natural complexes in big river floodplains has theoretical and practical importance, because in these valleys, which often cross different landscape zones; there is an expressive specific nature of a landscape structure. On the other hand, river valleys are the most cultivated areas. The Tom river valley is characterized by a composite landscape structure, which is conditioned by its location in a zone of transition from the Altai Mountain Region to the West Siberian Plain. The landscape systems of the valley have a high speed of natural transformations. Besides a lot of landscape systems have undergone serious anthropogenic modification. Particular intensive changes of the geosystems in the Tom valley are observed from the middle of the 20th century due to the increased industrial and agricultural activity (sand-gravel extraction from the bed of the river, drain-melioration, plough-lands), transport construction and expansion of the urban and rural areas. The purpose of this research is the analysis of the spatial structure of the Tom valley floodplain landscapes and their natural and anthropogenic changes. The Object of research is the Tom river valley floodplain near Tomsk. The subject of research is the differentiation of the floodplain landscape systems, their modern state, natural dynamics and anthropogenic modification. Both traditional methods of research in physical geography (including field expedition methods) and the newest methods of GIS-mapping and complex spatial analysis based on remote sensing data and digital elevation models are used. In the research, software is used: ArcGIS 10 (ESRI Inc.), ERDAS Imagine (ERDAS Inc.). The results are the following. The functioning of the floodplain landscape creates a dynamic equilibrium of the basic parameters of the structure of the landscape, and they have only periodic oscillations. Directional speaker floodplain landscape of the study area has the character of a gradual accumulation of quantitative elements of the new structure. Now, most of all, geosystems within Tomsk neighbourhood are subjected to the anthropogenic modification in some degree or other. Here, the vector of the geosystems dynamics is directed to the strong drying out in consequence of the decrease of the underground water level because of overlaid anthropogenic factors.

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