The Yellow River (YR) is the fifth-longest and the most sediment-laden river in the world. Frequent historical YR flooding events, however, have resulted in tremendous loss of life and property, whereas in recent decades YR runoff and sediment load have fallen sharply. To put these recent changes in a longer-term context, we reconstructed natural runoff for the middle reach of the YR back to 1492 CE using a network of 31 moisture-sensitive tree-ring width chronologies. Prior to anthropogenic interference that started in the 1960s, the lowest natural runoff over the past 500 y occurred during 1926 to 1932 CE, a drought period that can serve as a benchmark for future planning of YR water allocation. Since the late 1980s, the low observed YR runoff has exceeded the natural range of runoff variability, a consequence of the combination of decreasing precipitation and increasing water consumption by direct and indirect human activities, particularly agricultural irrigation. This reduced runoff has resulted in an estimated 58% reduction of the sediment load in the upper reach of the YR and 29% reduction in the middle reach.

黄河（YR）是世界上第五长和沉积最多的河流。然而，历史上频繁发生的YR洪水事件造成了生命和财产的巨大损失，而在最近的几十年中，YR径流和泥沙负荷急剧下降。为了将这些最近的变化放在一个长期的背景下，我们使用31个对湿度敏感的树年轮宽度年表的网络，重建了YR中游的自然径流回到1492 CE。在1960年代开始的人为干扰之前，过去500年的最低自然径流量发生在1926年至1932年的公元前，干旱时期可以作为未来YR水量分配计划的基准。自1980年代后期以来，观测到的低YR径流已经超出了径流变异性的自然范围，直接和间接人类活动（尤其是农业灌溉）造成的降水减少和水消耗增加的综合结果。径流减少导致YR上游河段的泥沙量减少了58％，中游河段的泥沙减少了29％。