M. M. Rogov’s Hydrology of the Amu Darya Delta is the second volume in a series of hydrological and geographical monographs on the estuarine regions of Soviet rivers prepared for publication by the State Oceanographic Institute. The Amu Darya Delta possesses enormous land and water resources, climatic conditions favorable for agriculture, and a population with centuries of experience in irrigated farming. For these reasons, it is of great importance to the national economy. The economic activity of the population of the Karakalpak Autonomous Soviet Socialist Republic is almost entirely dependent upon the utilization of the natural resources of the delta. However, the current use of the delta's natural resources falls far short of its potential possibilities. One of the reasons for this situation is the extremely rapid and profound changes occurring within its hydrographic network. In addition to its economic significance, the study of the Amu Darya Delta is of considerable value for the general theory of delta formation, since it represents a typical subtropical river delta characterized by a high sediment load. For this reason, the Estuarine Research Laboratory of the State Oceanographic Institute undertook a specialized long-term investigation of the hydrological regime and the dynamics of the hydrographic network, which constitute the most important controlling factors in the development of the delta's entire natural complex. The present monograph represents the culmination of these studies. The author of the monograph, M. M. Rogov, not only collected and systematized a vast body of published and archival materials, but also made extensive use of his own observations gathered during field expeditions to the delta between 1952 and 1954. In view of the diverse needs of specialists who may use this work in planning measures for the economic development of the delta, the author has included a large amount of factual and practical material.