| The Inner Mongolia reach of the Yellow River is located in high latitudes,which is affected by thermal,hydraulic,boundary conditions and human activities,and ice-flood occurs frequently.The water accumulation in the river trough caused by the ice resistance is called the tank water storage,which is one of the key factors leading to the occurrence of ice-flood disaster,and the evolution of its production and elimination process produces flooding.In this thesis,the key influence factor of flooding is the increment of tank water storage,and based on Landsat image data from 2000 to 2020 and Sentinel-2 image data from 2015 to 2020,we calculate the water volume of the river channel in Inner Mongolia reach of the Yellow River during 2000-2020.Based on this,we improve the calculation model of the water volume during the stable freezing period to obtain the water volume during the stable freezing period of the Inner Mongolia reach of the Yellow River from 2013 to 2020,and analyze the temporal and spatial changes.Finally,the correlation between the interannual variation of river water volume and the peak flow during the stable freezing period is used to predict the peak flow.The main research results are as follows:(1)Using optical remote sensing images and DEM data to estimate the river water volume during the smooth flow period of the Inner Mongolia section of the Yellow River,it is divided into four periods:"rising(2000-2003)-falling(2003-2008)-fluctuating(2008-2013)-stable(2013-2020)",in which The water volume in the"rising period"increases by 820 million m~3,the water volume in the"falling period"decreases by 1.28 billion m~3,and the water volume in the"fluctuating period"ranges from 1.02 to 1.93 billion m~3.The average amount of water in the"stable period"is 1.42 billion m~3.(2)Using the measured ice thickness data to improve the calculation method of river water volume during the smooth flow period,the study of river water volume during the stable closure period of the Inner Mongolia section of the Yellow River found that the lateral change of channel storage in this section shows a trend of contraction toward the main channel;the vertical change:the channel storage in the section of Shizuishan-Bayan Gaole increases along the way,the channel storage in the section of Bayan Gaole-Sanhuhekou does not change significantly along the way,the section of Sanhuhekou-Baotou increases and then decreases along the way,and the section of Baotou-Taodaoguai increases and then decreases along the way.(3)Through the stable sealing period,the water volume of the channel in the Bayan Gaole-Sanhuhekou section increases and then decreases.(3)The peak flow is predicted by the interannual variation of the river water volume during the stable closure period,in which the peak flow at Baotou and Toudaoguai stations is closely related to the river water volume variation with the correlation coefficients of 0.59 and 0.57,respectively.The relative errors are between 2% and 5%. |
