The book “The norm and variability of the annual flow of rivers of the Soviet Union”, created by the team of authors, is a unique study that immerses the reader in the world of hydrology and ecology of water resources. This publication will be a real find for those who are interested in natural phenomena, climate change and their impact on water systems, as well as for students and specialists in the field of ecology, geography and hydrology. The book addresses key aspects concerning river flow norms and variability, which is an important topic for understanding the country's water resources. The authors analyze data from different rivers, investigate factors affecting runoff, and offer a deep understanding of water dynamics in the context of climate change.[citation needed] The reader will be able to learn how various natural and anthropogenic factors affect the level and quality of runoff, which in turn is significant for agriculture, water supply and ecosystems. This work will be of interest not only to professional ecologists and researchers, but also to a wide range of readers, including students, teachers and anyone interested in the natural sciences. The book offers an accessible exposition of complex topics, which makes it useful for both specialists and amateurs. It can be an excellent addition to the library of anyone who wants to understand more deeply how water systems function and how they are subject to change. Topics raised in the book are relevant and important in light of contemporary environmental challenges. Climate change, water pollution, unsustainable use of water resources all these issues are becoming increasingly important in our society. The authors raise important questions about how to conserve water resources, how to adapt to changes in river flow, and how to ensure sustainable development based on scientific evidence. The book offers the reader not only theoretical knowledge, but also practical recommendations, which makes it especially valuable. The style of the authors is distinguished by scientific accuracy and clarity of presentation, which makes it easy to perceive even the most complex concepts. They use an extensive array of data and graphics, which helps to visualize information and makes reading more fun. This publication can be compared with other significant works in the field of ecology and hydrology, such as “Hydrology and water resources” or “Ecology of reservoirs”, which also offer an in-depth analysis of the state of water systems. The book “The Norm and Variability of the Annual Flow of the Rivers of the Soviet Union” is not just a scientific publication, but an important contribution to the understanding of ecosystems that will help readers realize how important water resources are for life on Earth. It will become an indispensable source of information for those who want to be aware of modern environmental problems and strive for a more sustainable future. If you are looking for a book that combines a scientific approach and the accessibility of the presentation, then this edition is exactly for you. It will not only enrich your knowledge, but also inspire further research in the field of ecology and hydrology. Do not miss the opportunity to get acquainted with this important work, which can change your view of water resources and their importance for our planet.