The purpose of the article was to characterize the international steam coal market based on the latest available data. The information goes back to the first half of 2018. The article focuses on the description of the three largest exporters and importers of steam coal. Representatives in these categories were selected using the latest global statistics on 2017. In 2017, global production of steam coal amounted to 5.68 billion tons and exceeded production in 2016 by 4%. For several years, invariably the world’s leading exporters of steam coal are: Indonesia, Australia and Russia. In total, these three countries in 2017 supplied 73% of steam coal to the international market. However, for the 46% of global steam coal imports (data for 2017), three Asian countries are responsible: China, India and Japan. For each of the six listed countries (i.e. for: three major global exporters and three major global importers), the paper presents volumes related to coal production, export or import. The directions of deliveries or major coal exporters to a given country were also included. At the end of the article, the price situation was presented, as it appeared in the first half of 2018 on the European and Asian markets.
Nutrient pollution such as nitrate (NO3−) can cause water quality degradation in rivers used as a source of drinking water. This situation raises the question of how the nutrients have moved depending on many factors such as land use and anthropogenic sources. Researchers developed several nutrient export coefficient models depending on the aforementioned factors. To this purpose, statistical data including a number of factors such as historical water quality and land use data for the Melen Watershed were used. Nitrate export coefficients are estimates of the total load or mass of nitrate (NO3−) exported from a watershed standardized to unit area and unit time (e.g. kg/km2/day). In this study, nitrate export coefficients for the Melen Watershed were determined using the model that covers the Frequentist and Bayesian approaches. River retention coefficient was determined and introduced into the model as an important variable.