2019-2020 年度黄河头道拐断面冰厚增长影响因素分析.

The research purpose of this paper is to obtain the information on the difference in ice thickness increase on the same section of the main stream of the Yellow River and its causes. Based on the data collected from observing the section freezing period at the Toudaoguai Hydrological Station in the winter between 2019 and 2020, the author analyzed the impact of ice thickness increase method, freezing degree days and flow velocity on the increase of ice thickness. The research results illustrates that the upper layer of the ice cap on the Toudaoguai section is formed by freezing ice. The area ranging from 400 m to 500 m of the left side bank is the nonmainstream zone and the ice increase at the measuring points in the interval is thermodynamic growth, mainly forming columnar ice. The area ranging from 500 m to 740 m of the left side bank is the mainstream zone and the ice increase at the measuring points in the interval is mainly ice accumulation and freezing, with relatively apparent difference in ice thickness. With the continuous increase of ice thickness, the daily increase of ice thickness is gradually decreased. The daily increase of ice thickness with frazilices at the bottom of the ice layer is greater than that without frazil slush accumulation. However when the ice thickness increases to a certain degree, the difference disappears. Freezing degree days is the main factor influencing the increase of ice thickness. The average velocity of the vertical line inhibits the increase of ice thickness. The presence of frazil ices at the bottom of the ice layer can promote the increase of ice thickness. [ABSTRACT FROM AUTHOR]