The book “IV Hydrological Conference of the Baltic States”, prepared by the team of authors, is a unique collection of scientific research, analytical reports and practical recommendations on topical issues of hydrology in the Baltic Sea region .. This publication is not just a collection of articles, but an important contribution to the development of hydrological science, bringing together experts from the Baltic region, scientists, engineers and specialists in the field of water resources, ecology and sustainable development. The focus of this book is on complex problems related to water management, climate change and their impact on the hydrosystems of the Baltic Sea and adjacent territories. The reader is waiting for an exciting immersion in the topics of monitoring hydrological processes, modeling water flows, assessing water quality and methods for preventing environmental disasters. Particular attention is paid to issues of cross-border cooperation, data exchange and development of strategies for adaptation to new climatic conditions, which makes the book a valuable resource for specialists working in the field of environmental safety and environmental management. "IV Hydrological Conference of the Baltic States" is intended for a wide audience - from students and young scientists interested in hydrology and ecology, to experienced researchers and practitioners looking for fresh ideas and solutions. This book is especially useful for environmentalists, water engineers, water management specialists, as well as representatives of government agencies responsible for environmental protection and the development of regional infrastructure. It will become an indispensable source of knowledge for those who want to understand how modern challenges, such as global warming and industrial development, affect the water systems of the Baltic region and what measures are being taken to preserve them. The book pays special attention to the interdisciplinary approach and integration of scientific data, which allows not only to highlight current problems, but also to offer innovative ways to solve them. It addresses topics related to hydrological modelling, flood risk assessment, water management in the face of climate change, and biodiversity conservation of aquatic ecosystems. Such a comprehensive view makes the publication not only a scientific work, but also a practical guide for the implementation of projects for the sustainable development of the region. The style of the authors is clear and accessible, which makes the book attractive even for those who are just starting their way in hydrology. At the same time, the wealth of information and depth of analysis allow experienced professionals to find new ideas and approaches here. The team of authors, united by a common goal - to promote the development of hydrological sciences and practices in the Baltic region, created a publication that deservedly occupies an important place in the scientific literature on environmental management and water resources. If you are interested in the topics of climate change, environmental sustainability, transboundary cooperation or are looking for up-to-date information on hydrological research of the Baltic countries, the IV Hydrological Conference of the Baltic countries will be a valuable source of knowledge and inspiration for you. This is a book that will help you understand the complex processes taking place in the water systems of the region, and find answers to the most important questions of our time. It is worth reading to everyone who is not indifferent to the future of our planet and wants to be aware of the latest scientific achievements in the field of hydrology and environmental management.