Modeling of the distribution of pollutants in the Dnipro River from the waste storage of the Prydniprovsky chemical plant

This article describes the study of the distribution of toxic streams in the Dnieper River using the physical three-dimensional model of the Dnipropetrovsk drainage basin and geoinformation methods for cartographic analysis of locality in the river on scale 1 : 100 000. The program Google Earth Pro ver.7.3 was used to make the landscape similar to the natural of the drainage basin. In the model, the confluence of the Konoplyanka river into the Dniprovsk Reservoir was chosen as the pollution discharge point. This river is in contact with buried chemical and nuclear waste of the Prydniprovsk Chemical Plant (Kamyanske city) in the upper part of the Dnipro reservoir. The model profile of the reservoir was created on an extruded polystyrene foam sheet measuring 100×50 cm by cutting it out. The formation of the profile of the water system was carried out taking into account the depths, changes in the slope of the Dnipro River and its tributaries (Oril, Samara, Mokra Sura) as well as the values of water discharge by these rivers. The spread of the pollutant in the water was simulated by emission a synthetic aniline dye of the green color to the point of contamination. The 3 levels of pollution were used in the process of work – small, medium and significant. They all differed by doubling the quantity of toxicants from the lower to the next higher level. In the model study, the paths of movement of pollutant-contaminated water masses along the stream were monitored. The RGB color value of perception showed the presence of radiotoxicant and its model concentration parameters when diluted. In the process of modeling, 5 repetitions of simulated pollution experiments of the Dnipro Reservoir were carried out along the river, with similar data obtained. Based on the results of the study, it was concluded that three-dimensional physical models built on spatial geoinformational landscape methods allow studying the processes of pollution of rivers of Ukraine by industrial waste, taking into account the slopes of the tributaries and its depth profiles. The model shows that an increase in the emission dose leads not only to an increase in the spread of the pollutant along the river, but also between islands and in shallow water zones due to turbulent diffusion across the river. At the same time, the zones of the mouths of incoming tributaries and "dead" backwaters (especially in the presence of a pronounced current in the main river) can remain practically uninfected. The parameters of the pollutant penetration function along the tributary of the Dnipro River are exponential in nature and linear in the semi-logarithmic coordinates. This means that doubling the concentration of the pollutant does not double the distance of its manifestation, but changes according to the logarithm to based 2. The water-soluble dyes of the model reveal traces of pollution along the river, their density of pollution can be estimated in the digital values of the colors of the GRB palette. At the same time, the visible absence of water color in the model (water transparency) does not mean the complete absence of a pollutant in it. The conclusion is that the physical modeling of the water passage process allows predicting the sequence of water contamination of the Dnipro Reservoir, indicating the time and places of their greatest and least impact on the biota.