黄河调水调沙“人造洪峰”在黄河口的沉积记录

Since the operation of Water-Sediment-Regulation (WSR) in 2002, the Huanghe (Yellow River) has become the worlds’ only big river system almost completely controlled by dam-reservoir regulation. “Human-made flood” during WSR delievers huge amounts of sediment to the sea in less than 20 days, which leaves clear sedimentation signal at the Yellow River mouth. This project will sample surface sediment, multi-cores and box cores at the river mouth area after the operation of WSR in 2018. The surface and core sediment will be analyzed for radionuclides (7Be, 137Cs and 210Pb), grain size, C, N and stable C isotope to determine the “flood sedimentation”. This “Human-made flood” sedimentation will be elucidated through analyzing the sediment transport pathway, sedimentation thickness, sedimentation distribution as well as sedimentation flux. The morphological effect of this sediment delivery on the subaqueous delta will be further examined.

2002年黄河实施调水调沙以来，黄河成为世界上唯一一条水沙输送完全受控于水库调蓄的大河。调水调沙以“人造洪峰”的形式在20天之内将巨量泥沙输送入海，必将在河口区留下清晰的沉积记录。本申请拟于2018年黄河调水调沙结束之后在河口区采集表层、多管和箱式柱状样，以表层和柱状沉积物为研究对象，采用放射性核素7Be、210Pb、137Cs为主要示踪剂，辅以沉积物粒度、C/N以及稳定C同位素测量，分别建立洪水沉积物分布范围和沉积厚度的有效识别指标，从入海泥沙的传输路径、沉积厚度、沉积范围、沉积通量等角度揭示黄河调水调沙“人造洪峰”在河口的沉积记录，阐明事件性输沙对水下三角洲沉积体的塑造效应。