THE RESEARCH AND MAPPING OF THE THERMAL IMPACT OF RAILWAY TRANSPORT NODES ON THE ENVIRONMENT FROM REMOTE SENSING DATA
Transport occupies one of the leading positions among the sectors of the country’s econo- my, providing territorial connectivity. However, an increasing number of communication routes and vehicles moving along them, lead to an increase in pollution of adjacent territories. The impact of transport on the environment is mainly studied from the point of pollution of the atmo- sphere and soil with the use of ground surveys, methods of chemical analysis of soil and water samples, modeling the spread of pollutants, etc., the role of remote sensing data is low. The re- search aimed at an assessment of the possibilities for recording the outgoing long-wave radiation of large transport junctions by satellite thermal imagery and revealing the patterns of spatiotem- poral changes in thermal radiation from their territories for several railway transport junctions. Images acquired at different seasons by the TIRS radiometer (Landsat-8) in 2014-2017 were used. The images were processed using the ArcGIS software package. The whole work flow chart included several stages, i.e. preliminary processing of thermal remote sensing data, calcu- lation surface temperature for each pixel and the creation of raster images of the thermal field; the combination of the calculated images of the surface temperature spatial distribution with a high-resolution image in the optical range and the creation on this basis of time series images of thermal fields for several transport, mainly railway, nodes; the analysis of the resulting maps. It appeared that stable thermal anomalies can be revealed by combining the temperature images of different seasons using the Weighted overlay tool. Thus, the multi-season temperature images of railway transport nodes, representing the space-time dynamics of the of thermal radiation intensity, were obtained and analyzed. The thermal anomaly of the railway node is an excess of the surface temperature by 2-5 оС relative to the average background value. At the same time, the railway junctions are markedly distinguished against the background of the surrounding territories in the absence of existing industrial enterprises (Rzhev, Arkhangelsk), dense urban development (Moscow, Arkhangelsk) or warm wastewater discharges (Bryansk) near the node, whose thermal background sometimes significantly exceeds the radiation of railway facilities. The possibilities of using satellite thermal images to detect thermal pollution created by transport nodes are limited, since a spatial resolution of 100 m (the highest for modern satellite thermal images) is often not enough to detect a thermal anomaly.