Evolution characteristics of the river course within Yinchuan Plain section of the Yellow River,from 1987 to 2022
To provide theoretical basis for the protection of the river channel,we study the evolution characteristics of the river channel in the Yinchuan Plain section of the Yellow River.Based on the Landsat satellite images of 8 periods from 1987 to 2022,the channel of the Yellow River is extracted by using the modified normalized water body index,the channel width,channel area,oscillation amplitude and oscillation rate in different periods are calculated,and the oscillation characteristics and the change rule of the Yellow River Yinchuan Plain section during 35 years are analyzed.The results show that the channel width decreased by 0.36 km on average,and the section area decreased by 0.66km2 on average during 35 years.The left bank of the river swings 0.10km to the right every year on average.As to the left bank swing rate,the ratio of the section R1∶R2∶R3 for left bank swinging to left is 1∶2.12∶2.53,and that for the left bank swinging to right is 1∶4.19∶5.33.The right bank of the river swings 0.004km to the right every year on average,and as to the right bank swing rate,the ratio of the section R1∶R2∶R3 for right bank swinging to left is 1:2.12:2.53,and that for the right bank swinging to right is 1∶4.19∶5.33.The river channel as a whole shows a trend of shrinkage and shifts to the right,and the degree of swinging change in the downstream of the Yinchuan plain section of the Yellow River is even more serious.The temporal changes of the river channel may be related to natural factors and human activities such as damming and impoundment,while the spatial changes may be limited by the differences in river runoff and riparian material composition.For the Yinchuan Plain section of the Yellow River,the protection construction should focus on the downstream reach.
NETL
NSTL
万方数据
