The scientific basis for predicting the migration processes of fertilizers and pollutants in the saturated-unsaturated media on irrigated lands and adjacent areas.

The impact of various agricultural activities of agro-industrial complexes on active water exchange zones essentially changes the hydrodynamic and hydrochemical surface and groundwater conditions, which in turn reflects on the changes in the positions of the groundwater levels and their degree of pollution. These processes are closely interdependent, particularly evident in the increasing level of groundwater pollution lately. Analysis of field data shows that the impact of contaminated adjacent natural environments on groundwater is much more significant than the inverse impact of groundwater on these environments. This aspect of the relationship between groundwater pollution and natural environments is critical regarding the overall research methodology for observations on groundwater quality and pollution sources. Existing studies only have recommendations for analyzing soil contamination processes, and there are no reliable mathematical models and calculation methods that fully account for complex natural and man-made conditions. This article presents the research results for developing a theoretical, systematic, and calculation basis to solve practical tasks on predicting the water-ecological situation at the spreading and migration of pollutants and fertilizers in irrigation zones and the substantiation of engineering recommendations for decreasing the negative influence the pollution processes among other things. The proposed methodology can be used by considering the composition of the main pollutants in specific areas where there is a need to make the urgent predictions and develop recommendations for the design and construction of protective engineering structures. This will help reduce the negative impact of the described processes on irrigation conditions in surrounding areas.