REMOTE SENSING APPROACH FOR THE THEMATIC MAPPING AND PHYSICAL-GEOGRAPHIC regionalization OF NORTH CAUCASUS

E.A. Belonovskaya, D.S. Asoyan

Institute of Geography RAS, Moscow, Russia

belena53@mail.ru

 

The Northern Caucasus is the well known nature model for in-depth study. The region is characterized by rich and original nature. The investigations were realized in the three key areas reflecting the environmental specificity of various parts of the Northern Caucasus: the Abisher-Akhuba Range in the Western; the Adylsu-river valley in the Central, and the mountain Guton in the Eastern Caucasus. The study comprises field observations of geobotanical and geomorphological elements, modelling of cartographic and climatic parameters, and the use of remote sensing. For these key areas a detailed interpretation of the relief and vegetation cover was done using the multispectral satellite images from the space system Resurs-F (three color filters, in scale of 1:200 000). More precise results were obtained by aerial photographs (in scale of 1:30 000), in order to avoid inevitable for the mountain landscapes effect of shadow and distortion of colour components on the satellite images.

On the base of the remote sensing the altitudinal belts and their borders are revealed. On the multispectral satellite images the exposed and turf-covered slope surfaces differ by various tints corresponding with various densities of grass cover. Coniferous (fir and pine) forests and deciduous woods are expressed on the satellite images by various tints of green. The main climatic parameters (mean annual temperature and annual total of precipitation) for the key areas had to be extrapolated. All analyzed indices depend linearly on the absolute altitude and coincide with the corresponding belts limits. The combined results of complex field observations and chamber studies underlay the thematic maps series for the key areas. The specificity of the altitudinal zonality structures in the various parts of the region and its objective borders are revealed and the base for the physiographic regional subdivision is prepared.

The application of remote sensing methods opens wide possibilities for studying the regularities and spatial heterogeneity of nature components in the mountain regions. It also improves the objectivity and precision in the determination of the mountain belts limits, the monitoring of their dynamics and therefore exactness of the environment evaluation in the mountains. This new approach is particularly effective in the complex researches and thematic mapping in the high mountains, where some missing parameters have to be modeled. It could change the type of studies from laborious and expensive field observations in the regions difficult of access into the almost chamber studies.