Statistical analysis of the Amur river water regime forecast

The Amur is navigable along its entire length, and it has a great transport importance for the Far East region. In years with spring-summer-autumn periods of low water level, the Amur River navigation suffers great economic losses. In such years, the volume of cargo transportation and the movement of passenger ships are disrupted, the work of water intakes deteriorates, and water supply to the population and enterprises is hampered. In the Khabarovsk Territory, material damage is sometimes commensurate with the damage from floods. More than a century of observations of the Amur regime near Khabarovsk made it possible to carry out a statistical analysis of the characteristic water level dynamics in three water phases: spring flood, summer low-water period and rain floods. The territory climate with cold dry winters and warm humid summers determines a dual maximum runoff in the Amur regime, reduced in spring and high in summer. It is noteworthy that both maximum runoffs have a steady downward trend in the dynamics of the highest water levels for 1896-2021. However, the height of the spring flood wave, in contrast to the annual maximums, decreases in dynamics more intensively (at a rate of 10-12 cm / 10 years and 5-7 cm / 10 years, respectively). The lowest water levels observed after the flood wave (summer low water period) have a long-term trend in dynamics, parallel to the spring trend. A similar trend in the Amur regime is associated with the variability of the regional climate and is synchronous with global warming characterized by an increase in surface air temperature, which contributes to an increase in evaporation from the water surface, and therefore, to a decrease in river runoff. The performed assessment of the Amur water regime during the navigation period makes it possible, by means of trend components, to orient the hydrologist-forecaster on the distribution of the Amur water content in in the coming season.