The diversity of transition zones is considered, the main features of ecotones are indicated, and the degree of knowledge of the mouth areas of tributaries of reservoirs is analyzed. A review and analysis of the concept of the estuary region and approaches to zoning the estuarine regions of rivers carrying water to the seas and oceans is provided. Based on the high biological potential, the great role in the life of receiving reservoirs, significant areas and extremely scarce data, the task is set of detailed comprehensive studies of the mixing zones of river and reservoir waters, as well as areas of bordering water bodies, that is, the tributary itself and the reservoir. The principles of identifying different types of zones in the mouth areas of tributaries of lowland reservoirs based on the electrical conductivity of water are presented, and the names of the selected areas are given.

考虑过渡带的多样性，指出交错​​带的主要特征，分析水库支流河口区的认识程度。对河口区域的概念以及向海洋输水的河流河口区域进行分区的方法进行了回顾和分析。基于生物潜力高、对受纳水库生命力的重大作用、区域重要、数据极其稀缺等特点，对河水库混合区以及接壤水体区域进行了详细的综合研究，即支流本身和水库。提出了根据水的电导率识别低地水库支流口区不同类型区域的原则，并给出了所选区域的名称。