Transformation processes in the river-basin system of Bystrytsia and their geoinformation-cartographic models

Abstract

The problem of assessing the scales and direction of the development of transformation processes that occur in river systems and components of the natural environment of their basins under the influence of a wide range of factors in the long run, remains an urgent task. This is due to the diversity of human and societal impacts on river basin systems (RBS) and the need to assess the effects of global and regional climate change and their impact on water runoff, sediments and solutes discharges, the geoecological status of river basin systems. To a large extent, this applies to the river basin systems of the Carpathian region, thus the river basin system of Bystrytsia is being selected as a study object, as well as the right-bank tributary of the Dnister, located in IvanoFrankivsk region and covering mountain (Ukrainian Carpathians) and foothill (Precarpathian) landscapes with peculiar natural and economic conditions. This RBS is typical for the Carpathian region, so the results will also reflect the situation in other RBS. The aim of the paper is the quantitative assessment of the scales and long-term trends in the development of transformation processes in the structure of the river basin system of Bystrytsia , the exploration of the range of factors responsible for these changes and their geoecological consequences and the reflection of the results on a series of cartographic models of RBS. The performed research is based on a complex technique, which combines methods of cartometric analysis of the structure of river systems on the basis of different time (1855, 1925, 1955, 1975, 2008) topographic maps of scale 1: 100 000; methods of analysis of the state of landscape components (soils, forest cover, land structure, etc.) and their long-term changes; methods of analysis of monitoring data on changes of objects and development of processes (water, sediments, and dissolved substances of runoff in rivers, manifestation of erosion, mudflow, landslide, karst, mining processes; industrial, agricultural, forestry and water management activities, sewage discharges, surface water and groundwater intake, etc.); methods of remote sensing data analysis and geoinformation-cartographic modeling. As a result of the performed research the conceptual model of transformation processes in river basin systems which occur under the influence of natural and anthropogenic factors is developed, parameters of structure of river systems are defined (number of rivers of different orders, their length, general order of RBS on each "time slice" of its state), the scale of development of transformation processes in RBS Bystrytsia from one time slice to the next and for the whole studied period, the degree of influence of natural and anthropogenic factors on these transformations and their geoecological consequences is revealed and estimated as well. A series of digital maps of RBS Bystrytsia have been compiled, which reflect the main results of the research. A set of environmental measures aimed at improving the river and basin system of Bystrytsia and measures to optimize nature management is substantiated.