2018年~2022年三门峡水库运用与河道冲淤分析

Analysis of Sanmenxia Reservoir Operation and River Erosion and Siltation from 2018 to 2022

2018年11月~2022年10月,三门峡水库来水来沙,洪水情况,水库冲淤情况及潼关高程发生新的变化。①来水较丰,潼关站年均径流量为393.74亿m^(3),沙量主要来源于汛期,约占全年88%。②共发生21次洪水,洪水期年均来水量134.4亿m^(3),占汛期来水量的62%。③各年汛期累计散泄天数分别为19天、23天、28天、18天和13天。④潼关以下河段发生了累积性的冲刷,冲刷量达0.874亿m^(3)。2020年与2022年由于水库过早结束汛期运用向非汛期过度发生淤积外,其余各年均冲刷。⑤潼关高程从2017年汛后到2022年汛后累积下降0.21m,2020年和2021年黄淤41断面上下断面发生冲刷,汛后潼关高程分别较前一年降低0.51m和0.49m,2022年非汛期潼关高程有较大幅度回淤抬升,汛后潼关高程较上一年抬升0.58m。

From November 2018 to October 2022,the water and sediment inflow of the Sanmenxia reservoir,the flood situation,the reservoir scouring and silting situation and the Tongguan elevation have undergone new changes.The water inflow is relatively abundant,and the average annual runoff of Tongguan station is 39.374 billion m^(3).The sediment volume mainly comes from the flood season,accounting for about 88% of the whole year.A total of 21 floods occurred,with an average annual water inflow of 13.44 billion m'during the flood season,accounting for 62% of the water inflow during the flood season.The cumulative number of open discharge days during the flood season in each year was 19 days,23 days,28 days,18 days and 13 days respectively.Cumulative scouring occurred in the river section below Tongguan,with a scouring volume of 87.4 million m^(3).In 2020 and 2022,except for the excessive silting caused by the premature end of the flood season operation of the reservoir to the non-flood season,the rest of the years were scouring.The elevation of Tongguan dropped by 0.21 m from the post-flood period in 2017 to the post-flood period in 2022.In 2020 and 2021,the upper and lower sections of the Huangyu 41 section were eroded.The elevation of Tongguan after the flood period dropped by 0.51 m and 0.49m respectively compared with the previous year.In the non-flood season of 2022,the elevation of Tongguan rose significantly due to silting.The elevation of Tongguan after the flood period rose by 0.58 m compared with the previous year.