小浪底大坝运行前后黄河径流变化与预测研究

Research on the Runoff Change and Prediction of the Yellow River before and after Xiaolangdi Dam Operation

黄河流域生态保护与高质量发展离不开黄河水资源的合理调配,黄河径流在维持全球能量平衡、水沙循环以及气候变化和生态环境演变的过程中也发挥着关键作用。大坝强烈改变河流水资源的时空分布格局,干扰河流的自然节律。小浪底大坝是中国第二大水利工程,通过整理大坝运行前后花园口水文站数据,运用变化范围(Range of Variability Approach,RVA)、Theil Sen斜率、Mann-Kendall突变检验和小波等方法分析黄河径流的变化程度、幅度、突变点和周期,结果表明:大坝建后,花园口径流极大值提前。年均径流减小趋势通过了99%的显著性检验,1998-2011年减小趋势最为明显,1990年和2012年分别有突变点出现。径流有明显的周期性变化,主周期偏低等值线中心在2000年前后。由突变检验和小波分析结果可以预测今后一段时期年径流将处于偏低的时期。调水调沙期间水量大、含沙量高和水量的快速消退,使许多引黄涵闸口和引水渠系淤积比较严重。弄清黄河径流变化规律,适时调整大坝运行管理、区域国土空间规划和国民经济发展规划等决策,可为黄河中下游生态保护和高质量发展奠定基础。

The ecological protection and high-quality development of the Yellow River Basin cannot be separated from the rational allocation of water resources of the Yellow River.The Yellow River runoff plays a key role in maintaining global energy balance,water and sediment cycle,climate change and ecological environment evolution.Dams strongly change the spatial and temporal distribution of water resources and interfere with the natural rhythm of rivers.Xiaolangdi Dam is China’s second largest water conservancy project,the data of Huayuankou Hydrological Station before and after the operation of the dam are sorted out by using the Range(the Range of Variability that RVA),Theil Sen slope,Mann Kendall mutation test and methods of wavelet analysis of the degree of the change of the Yellow River runoff,amplitude,point mutation and period.The decreasing trend of annual runoff passed 99%significance test,which was the most obvious from 1998 to 2011,and the abrupt transition point appeared in 1990 and 2012.The runoff had obvious periodic changes,and the main period was lower than the contour center around 2000.The results of mutation test and wavelet analysis can predict that the annual runoff will be low in the future.During the period of water and sediment regulation,the siltation of many Yellow River sluice gate and diversion canal system is more serious due to the large amount of water,high sediment concentration and rapid water regression.The rule of runoff variation in the Yellow River is made clear,and the decision-making of dam operation management,regional territorial spatial planning and national economic development planning is adjusted,which can lay a foundation for ecological protection and high-quality development in the middle and lower reaches of the Yellow River.