不同来源水沙对黄河入海泥沙通量的影响

SEDIMENT FLUX INTO THE SEA AS INFLUENCED BY DIFFERENT WATER AND SEDIMENT SOURCES IN THE DRAINAGE BASIN: AN EXAMPLE FROM THE YELLOW RIVER, CHINA

文中研究了黄河入海泥沙通量与流域上、中游不同来源区的水沙量之间的关系 ,并以年系列和洪水系列水文泥沙资料 ,建立了表达这一关系的经验统计模型。所建立的模型表明 ,来自不同来源区的泥沙 ,对于入海泥沙通量的影响是不同的。来自多沙细沙区的每 1t泥沙 ,输送入海的为 0 .85t(年系列 )和 0 .72t(洪水系列 ) ;而来自多沙粗沙区的每 1t泥沙 ,输送入海的仅为 0 .34t(年系列 )和 0 .2 1t(洪水系列 )。 70年代以来入海泥沙通量的减少 ,与多沙细沙区水土保持工作的开展有密切关系。将文中的模型与已建立的黄河流域水土保持减水、减沙模型相耦合 ,可以用来预测未来因人类活动和气候变化而使不同来源区的水沙进一步减少时 。

The runoff and sediment of large rivers usually come from different source areas, which make different contributions to the sediment flux into the sea. This has been studied with an example from the Yellow River in China, whose suspended sediment flux into the sea accounts for a large percentage of the total of the world. The drainage basin of this river can be divided into 4 major water and sediment source areas. The sediment flux into the sea is closely related to the water and sediment from the different source areas in the drainage basin and, accordingly, an empirical regression model has been established to express this relationship. According to this model, for each unit amount of sediment from the fine sediment producing area (FSA), 85% (for annual series) or 72% (for event series) can be transported into the sea; however, for the sediment from the coarse sediment producing area (CSA), only 21% (for annual series) or 34% (for event series) can be delivered to the sea. Since the 1970s, the Yellow River's sediment flux into the sea has declined markedly and this reduction can be attributed to a great degree to the soil control measures in the fine sediment producing area. Combining the model of this study and the previously established models for estimating the water and sediment reduction caused by soil control measures in the Yellow River basin, quantitative prediction may be made for the change of sediment flux caused by climate change and human activities in the future.