ANALYSIS OF TEMPERATURE REGIME OF LAND SURFACE FOR BYSTRYTSIA RIVER BASIN AND THE INFLUENCE OF TERRAIN ATTRIBUTES USING LANDSAT 8 DATA

Abstract

Terrain morphology is a powerful factor influencing climate characteristics, which manifests itself at various scale levels. At the detailed scale, this effect is mainly due to the redistribution of solar radiation on surfaces and slopes of different slope and aspect, which causes their unequal heating, and local redistribution of air masses. Spatial distribution of land surface temperatures can be effectively studied using remote sensing data in far-infrared range, which can be recalculated into temperature values. The values of the land surface temperature in the Bystrytsia river basin were calculated with far-infrared channels of Landsat spatial images for three time slices: October 5, 2013, February 13, 2015, August 10, 2016. The statistical analysis has been carried out on the impact of terrain morphometric parameters and land surface type and characteristics on its temperature. To determine the relative influence of each specific factor, the method of hierarchical partitioning has been implemented with the hier.part package of R software environment. Significant seasonal differentiation of the influence of individual factors on temperature was revealed. During all the seasons of the year, absolute height appeared as the most significant factor among those analyzed. The influence of absolute height on temperature distribution was the strongest in autumn, somewhat weaker in winter and the weakest in summer. Artificial surfaces, dry grass and soil were heated more strongly despite their lower albedo due to smaller heat consumption by evaporation, whereas vegetation surface and wet soils were less heated. On the other hand, the influence of relative surface insolation, being differentiated by terrain elements appeared to be relatively weaker, which can be explained by the calculation method used (insolation has been calculated for the moment the images were taken, whereas surface heating takes some time). The influence of the level of surface moisture also appeared to be significant. Key words: land surface temperature, Landsat, Bystrytsia, morphometric parameters, hierarchical partitioning.