GEOECOLOGICAL ASSESSMENT OF LAND USE STRUCTURE OF GNIZDECHNA SMALL RIVER BASIN
Authors: Kuzyk Ihor , Vitenko Ihor , Tsaryk Volodymyr 
Published: June 2022

Gnizdechna river is a right tributary of the Gnizna river (Dniester basin) and flows in the central part of the Ternopil region. The length of the river is 39 km, the area of the basin is 26 400 ha, the average depth is 1,5 m, the slope of the river is 1,8 m/km. The valley of the Gnizdechna river is partially melioration and regulated, there are 4 ponds on the river. The aim of the article is to assess the geo-ecological parameters of the land use structure of the small Gnizdechna river basin. The following methods were used to achieve this goal: descriptive, geoinformation, statistical, mathematical and geoecological analysis, as well as special methods for determination  the anthropogenic load, coefficients of ecological stability and anthropogenic transformation of the Gnizdechna river basin. The structure of land lands in the Gnizdechna river basin was analyzed. It was found that the structure of land use of the study area is dominated by arable land (65%), forests occupy 10%, built-up land - 6%, pastures - 9%, hayfields - 5%, perennials – 1,5%, land under water and swamps – 1,5%. The share of natural lands in the Gnizdechna river basin is 27%. The reserve of the basin is 17% (22 objects of the nature reserve fund, with a total area of 4420,5 hectares).

According to the results of calculations, the article defines the coefficient of anthropogenic transformation landscapes of the Gnizdechna river basin which is 5,88; the coefficient of ecological stability of the study area - 0,3; anthropogenic load score - 3,7; anthropogenic load factor - 3,3. According to the obtained results, it is established that the territory of the Gnizdechna river basin is ecologically unstable with moderately transformed landscapes, rather high score and average degree of anthropogenic load. The prospect of further research remains the rationale for measures to optimize the structure of land use in the Gnizdechna river basin, in which it is necessary to provide for an increase in the forest cover of the study area by changing the purpose of individual land plots and the organization of their landscape-adapted use.

According to the results of the geoecological assessment of the land use structure of the Gnizdechna river basin, it can be concluded that the landscapes of the study area are moderately transformed, ecologically unstable with a sufficiently high anthropogenic load. Such indicators are due to high agricultural development of the basin (82%) and, accordingly, plowing - 65%, low share of forested land (10%) and other natural lands (pastures, hayfields, perennials, underwater lands and swamps - 17%) . Which in turn forms a low share of natural lands in the basin of the studied small river - 27%. At the same time, in the basin of the river Gnizdechna there are 22 objects of the nature reserve fund with a total area of ​​4420.4 hectares, which forms a reserve of the studied area of ​​17%. To optimize the structure of land use in the Gnizdechna River basin, it is necessary to justify and implement a number of measures, which should be based on landscape-adapted land use, reduce plowing and increase forest cover, due to unproductive and highly eroded lands. The formation of an ecologically safe system of nature management in the basin of the studied small river will help to improve the geo-ecological situation in the basins of the rivers Gnizna, Seret and Dniester.

Key words: Gnizdechna river, river basin, land use, anthropogenic load, natural lands, Ternopil region.