Assessment of the Anthropogenic Load on Water Bodies of the Ob–Irtysh Interfluve: Inventory of Pollution Sources, Comparative Analysis of Direct and Indirect Impacts

Anthropogenic load was assessed using two groups of indicators of direct (organized) and indirect (diffuse) impacts on the example of small rivers in the closed region of the Ob−Irtysh interfluve. Among the many assessment methods, those that have been tested in geographic and hydrological studies have been selected. Detailing and verification of the results of the assessment was carried out using remote sensing, field research, chemical-analytical and statistical methods. The assessment showed that the main sources of pollution of water bodies are the territories of rural settlements, livestock farms (complexes), areas for walking livestock and poultry, household waste dumps and municipal solid waste, that is, sources of diffuse pollution. There is a higher level of load within the drainless region of the Altai krai in comparison with the Novosibirsk oblast, which is associated with a more intensive development of the agricultural sector of the region’s economy. An inventory of sources of anthropogenic impacts by remote sensing methods revealed some difficulties, such as difficulties in determining existing facilities and their uses, a mismatch in the number of livestock complexes identified using the register of organizations and by visual interpretation of space images. The analysis of calculated data on phosphorus and nitrogen loads on individual water bodies is confirmed by estimates based on the results of field hydrological and hydrochemical studies.