<p>The analysis of the hydrochemical regime of the rivers feeding the irrigated territories of agricultural land in the river basin is essential to develop scientifically based recommendations on the rational use of water and land resources. Anthropogenic influence on water and land resources in the basins of the rivers inevitably affects the change of surface water quality. A new method is proposed for analyzing the hydrochemical regime of the rivers based on three-dimensional (3-D) modelling of the spatio-temporal distribution of water mineralization along the length of the main river. This method allows to analyze the flow of pollutants into the river, identify the main causes of pollution <br /> and the formation of the hydrochemical regime of rivers.</p>