(On the base of geological and geobotanical investigations)

Glushkova N.V.

V.S. Sobolev Institute of Geology and Mineralogy sb ras, Novosibirsk, Russia

hope@igm.nsc.ru

A characteristic feature of the Novosibirsk Academyctown is a diffuse development, "the basis of which is the interpenetration of living and working quarters, and large amounts of untapped natural trees" [1], which allows you to call him Ecopolis in its modern sense [2]. Thus, the city-forest or Ecopolis for V.V. Vladimirov [2] is a heterogeneous natural and man-made system for which characterized the spatial mosaic distribution of a different types of terrain. Therefore, to study ecosystems of Academyctown using complex technology of GIS modeling of complex natural and human systems, which developed on the basis of the technology of heterogeneous environmental systems (HES) [3]. This allows not only the map, but also to assess the contribution of different types of natural and man-made objects (depending on their percentage) in the HES.

For mapping forest cover of Academyctown (the territory of the Pirogov forests and the Central Siberian Botanical Garden, CSBG SB RAS), we used the analysis and comparison of two high-resolution satellite imagery QuickBird: late autumn and summer [4]. Autumn image used for the selection of conifers, as species of deciduous trees have dropped their leaves, and pine still remained green. Technology of automatic classification of high-resolution image was developed to estimate the density of the forest and the ratio coniferous and deciduous trees. The technology consist of in conducting the classification of satellite images, convert classification results into a vector format, and the subsequent construction of density grids. In carrying out the maximum likelihood supervised classification in the autumn image were allocated area of coniferous forests. The resulting class is converted into a vector layer showing the distribution and the closeness of coniferous trees in the studied forests. In the summer image deciduous and coniferous tree species are close in the space of spectral features and difficult to recognize by the methods of automatic classification. However, this picture represents true picture of distribution and canopy of deciduous trees in the forests of Academyctown, while the characteristics of their closeness obtained at the late autumn images greatly underestimated. Vector obtained by classifying the summer image by maximum likelihood method, is presented as a canopy of deciduous and coniferous trees. In order to highlight the crowns from the vector of all deciduous and coniferous forest trees was carried out overlay operation. For this purpose the vector layer of coniferous trees, derived from the autumnal image overlay on the vector layer of all the forest derived from summer image The result was obtained by three types of objects: the crown of coniferous trees, the crowns of deciduous trees and open spaces. In order to divide the vector projections on the crowns of the forest deciduous and coniferous trees was carried out overlay operation. For this the vector projection of crowns of coniferous trees, derived from the autumn image imposed on the vector of all the forest and get the location of pine trees. Then a series of density schemes (with a cell size grid of 2,5 m and 50 m radius of the window) were constructed, reflecting the projection of summer crowns forests, forests by the ratio of pine and deciduous woods.

Then the study area of Academyctown was divided into areas of geological and geomorphological grounds. The three terraces, the watershed, and the transition zone between them were allocated. The boundaries were based on analysis of satellite image and digital elevation model (DEM). Then overlay operations were carried out with the geological and geomorphological scheme and the scheme of vegetation, built by satellite images. Finally we got the dependence of vegetation on the geological-geomorphological structure of the territory. Analysis of the patterns showed that on the terraces is dominated by coniferous and deciduous-coniferous forests, and deciduous and coniferous-deciduous in the sum does not exceed 7%. On watersheds, by contrast, deciduous and pine-deciduous forests is dominated (in the amount of about 97%). In the intermediate zone between the terraces and the watershed mixed forests is dominated - pine-deciduous and deciduous-pine, and clearly visible to the correlation of density - the denser it is, the greater is the area, and deciduous and coniferous forests of different density occupy less than 12%.

The comparative analysis of the natural-spatial structure of the two major forest areas using GIS technology and remote sensing data showed highly informative method, the ability to identify relationships between geomorphological features of the territory, the composition of surface deposits and the structure stands. The method makes it possible to assess whether the present structure and the closeness of the stand reflect the range of natural causes, and how preceded human activities effect on these parameters. Using high resolution satellite images and modern GIS technology allows for the operational monitoring of forest conditions and a rapid assessment of the degree of anthropogenic transformation.

References:

1. Nature of Academyctown: 50 years later / executive Editor I.F. Zhimulev. Novosibirsk: Publishing House of SB RAS, 2007. 250 p.

2. Vladimirov V.V. Urboecology Lectures. - M: MNEPU, 1999. 204 p.

1. Zolnikov I.D., Lyamina V.A., Korolyuk A.Y. Complex technology of mapping and monitoring heterogeneous landscapes // Geography and Natural Resources. 2010. № 2. P. 126-131.

2. Glushkova N.V., Zolnikov I.D., Lyamina V.A., Makunina N.I., Mal'tseva T.V. Mapping of the forests of Central Siberian Botanical Garden // Bulletin of the NSU. - 2010. - Volume 8, № 3. P. 83-91