River networks are typically treated as conduits of fixed discharge conveyance capacity in flood models and engineering design, despite knowledge that alluvial channel networks adjust their geometry, conveyance, planform, extent and drainage density over time in response to shifts in the magnitude and frequency of streamflows and sediment supply. Consistent relationships between modes of climate variability conducive to wetter-/drier-than-average conditions and changes in channel conveyance have never been established, hindering geomorphological prediction over interannual to multidecadal timescales. This paper explores the relationship between river channel conveyance/geometry and three modes of climate variability (the El Niño–Southern Oscillation, Atlantic Multidecadal Oscillation, and Arctic Oscillation) using two-, five- and ten-year medians of channel measurements, streamflow, precipitation and climate indices over seven decades in 67 United States rivers. We find that in two thirds of these rivers, channel capacity undergoes coherent phases of expansion/contraction in response to shifts in catchment precipitation and streamflow, driven by climate modes with different periodicities. Understanding the sensitivity of channel conveyance to climate modes would enable better river management, engineering design, and flood predictability over interannual to multidecadal timescales.

尽管知道冲积河道网络会随着时间流的大小和频率的变化而随时间调整河道的几何形状，流量，平面形式，范围和排水密度，但在洪水模型和工程设计中，河网通常被视为固定流量的管道。和沉积物供应。从来没有建立过有助于变湿/变干的平均条件的气候变异模式与河道输送量之间一致的关系，这阻碍了对年际至多年代际尺度的地貌学预测。本文探讨了河道输送/几何与三种气候变率模式之间的关系（厄尔尼诺-南方涛动，大西洋多年代际涛动和北极涛动），其中两个，美国67条河流在过去七年中的渠道测量，流量，降水和气候指数的五年和十年中位数。我们发现，在这些河流的三分之二中，响应于集水区降水和水流的变化，在不同周期性的气候模式的驱动下，河道通行能力经历了扩张/收缩的连贯阶段。了解河道输送对气候模式的敏感性，可以在跨年际到数十年的时间尺度上实现更好的河流管理，工程设计和洪水可预测性。在具有不同周期性的气候模式的驱动下，河道通行能力响应于集水区降水和水流的变化而经历了扩张/收缩的连贯阶段。了解河道输送对气候模式的敏感性，可以在跨年际到数十年的时间尺度上实现更好的河流管理，工程设计和洪水可预测性。在具有不同周期性的气候模式的驱动下，河道通行能力响应于集水区降水和水流的变化而经历了扩张/收缩的连贯阶段。了解河道输送对气候模式的敏感性，可以在跨年际到数十年的时间尺度上实现更好的河流管理，工程设计和洪水可预测性。