<p>This book explores the changes in Amu Darya runoff and its hydrochemical patterns under modern conditions and future impacts of the construction of water conservancy projects in the basin. The main contents include: natural conditions, water resources and water conservancy project construction in the Amu Darya River Basin; changes in runoff during the vegetation and non-vegetation periods; changes in water chemical patterns and their impact on economic activities; possible future water conservancy measures on runoff. Quantitative impact. introduction The increasing use of water resources to meet economic needs has led to significant changes in river runoff, water conditions in its basins and water-receiving areas. The impact is particularly significant in arid and semi-arid areas, where there are few rivers whose runoff is not being economically utilized. In many areas,"the scale of human activities in land water resource management has begun to compare with the impact of natural factors on them." 4040 In the future, when it is planned to irrigate tens of millions of hectares of new land and implement a grand cross-basin water transfer project 4747, the impact of human factors will be even greater. Under these conditions, without reliable knowledge that water conditions and river runoff have changed due to human factors, the reasonable and most effective use of water resources in the future will be impossible. More importantly, it is necessary to foresee the changes that will occur as a result of the implementation of planning measures. "Finding the optimal ratio between land water consumption and replenishment conditions is one of the most important issues, and its solution largely determines the living conditions of human society and the face of the earth." 4040. One of the founders of hydrological science.Г. Glushkov 2525 wrote as early as the early 1930s that in the future "hydrology will have to shift from studying natural water bodies to studying changed water bodies, and its deviation from natural conditions will gradually increase." In recent years, measures to strengthen the use of runoff have been carried out so rapidly around the world and in our Soviet Union, and the problem of runoff changes under the influence of human factors has been so significant that the center of hydrological research is increasingly actively shifting from the field of runoff formation to its utilization field. More and more studies on runoff, its modality and mineralization changes under the influence of human economic activity51,83,10451,83,104 eloquently illustrate this point. The conclusions of these studies on the impact of human factors on river runoff are often contradictory, which is related to the great complexity of the issues studied and the lack of original information. Among all measures affecting river runoff in Central Asia, the main ones are irrigation, regional drainage, and reservoir regulation of runoff. Industrial-domestic water consumption (non-regressive) has increased over time, but is negligible compared to irrigation water consumption. Therefore, anthropogenic changes in river runoff in Central Asia are mainly caused by the impact of water conservancy improvement measures. The impact of the latter is mainly reflected in three aspects: a) changes in river runoff and its modality over time and along the course; b) changes in water quality; and c) changes in the water balance structure of irrigated areas. Taking the Amu Darya Basin as an example, this paper evaluates changes in river runoff, its modality and mineralization under current and future conditions. (This content is AI translation and the translation accuracy is not guaranteed. Please refer to the original text for details) </p>