Geoinformation modeling of antropogenic transformation of the basin geosystems (case study of Dnister right tributaries)

Abstract

The purpose of the article is to analyze anthropogenic transformation of river-basin geosystems of the outer Subcarpathian region by geoinformational modeling tools using various methods of quantitative estimation of anthropogenic pressure; comparison of modeling results on the basis of administrative-territorial and natural units, selection of optimal structural units for the study of anthropogenic changes in basin geosystems. Research methods. The features of estimation methods of anthropogenic transformation level of territorial complexes, based on various conceptual approaches to the study of anthropogenic changes in the components of the environment were investigated. In particular, the article compares methods of F.M. Milkov, P.G. Shyshchenko, E. Klementova and V. Geinige, P.P. Borschevsky, M.V. Boyarin, I.P. Kovalchuk, N.M. Ridey and D.L. Shofolov, A.M. Tretyak and others and by the means of geoinformation modeling of river-basin geosystems (namely, the case study of the outer Subcarpathian Dniester tributaries) shows the degree of representativeness of the results produced by each of them. It is noted that the technique by P.G. Shyshchenko allows to more accurately reflect the state of anthropogenic transformation of the river-basin system’s natural conditions Results. A range of digital cartographic models was developed to evaluate and compare anthropogenic transformation level of the two Carpathian basin systems and to identify similar and distinctive features of the state and the transformation level of the basin systems’ natural environment andstability of agricultural and forest landscapes in the studied basin geosystems. In particular, the study has revealed that the anthropogenic transformation of the outer Carpathian river basins is rising downstream. In the upper parts of the basins, it manifests itself in deforestation, while in the lower parts agricultural influence dominates. In addition, the index of anthropogenic transformation is rising with an increase in the order of sub-basins. The worst conditions of agro-landscapes are observed in the reclaimed valleys of the main rivers and their tributaries (due to the considerable level of plowing in the plain parts of the basins due to low fertility of soils, high levels of their acidity, degradation processes and chemical pollution). Stable territories are inherent exclusively in sub-basins which remain in their natural state or bear only traces of human activity. Settlements, which influence adjacent areas, are characterized by unsustainable land use. As for anthropogenic transformation, in the basin geosystem of the Berezhnytsia river its indicators increase upwards due to an increase in the share of arable land. On the contrary, in the basin of Bystrica much more land is occupied by industrial facilities, which affect the components of the geosystem the hardest. In this regard, the largest values of nature anthropogenic transformation indicators are found in the northern part of the basin and upstream of the city of Nadvirna and the town of Bykiv. Scientific significance. Case study of the administrative regions and the river basin located within them reveals the advantages of studying the geoenvironmental state of the territories according to their natural geographic taxonomic units, which allows to determine the most strained areas in geosystems. Particular attention is paid to the choice of optimum sized geospatial objects during the study of diverse basin systems. River sub-basins of the third order (according to the classification scheme of A. Strahler) were chosen to this purpose. Their size corresponds to that of the combined territorial communities’ area. The importance of formation a database that reflects on the state of the geospatial entities under study is emphasized. For this purpose, it is appropriate to convey the structure of land use, represented by indices of different land cover and land use types (protected areas, forest covered areas, swamps and wetlands, meadows, gardens and vineyards), arable land, land under rural and urban development, natural objects modified by human activities (reservoirs , ponds, channels), land utilized by industry and transport in each investigated object. The article shows that the best solution to this problem is provided by the processing of high-resolution spatial (in panchromatic and multispectral) remote sensing data. The most appropriate in this case are QuickBird satellite imagery, designed to create and update topographic maps and plans, to make inventories of forests and agricultural lands and to assess their condition, therefore allowing mapping of land use types that are not identified in statistical inventories. Practical significance. The results of this work will be helpful in selecting the specific technique allowing the most complete representation of anthropogenic transformation of natural objects; in choosing the most optimal spatial units to carry out the analysis and, accordingly, to fill in the database. The developed models reveal the most anthropogenically loaded parts of river-basin geosystems of the outer Subcarpathian region, which is essential for the extrapolation of the obtained results to other right tributaries of the Dniester River.