River networks are striking features engraved into the surface of the Earth, shaped by uplift and erosion under the joint influence of climate and tectonics. How a river’s gradient changes as it descends along its course—its longitudinal profile concavity—varies greatly from one basin to the next, reflecting the interplay between uplift and erosional processes. A recent global analysis has suggested that climatic aridity should be a first-order control on river profile concavity, but the importance of climate relative to other factors has not been tested at global scale. Here, we show, using recent global datasets of climate, river profiles and tectonic activity, that tectonics is much more strongly expressed than climate in global patterns of river profile concavity. River profiles tend to be more strongly concave in tectonically active regions along plate boundaries, reflecting tectonically induced spatial variations in uplift rates. Rank correlations between river profile concavity and four global tectonic proxies (basin-averaged channel gradients, distance to plate boundaries and two measures of seismic activity) are much stronger than those between river concavity and three climate metrics (precipitation, potential evapotranspiration and aridity). We explain the association between tectonic activity and increased river profile concavity through a simple conceptual model of long-term uplift and river incision. These results show that tectonics, and not climate, exerts dominant control on the shape of river longitudinal profiles globally.

河网是刻在地球表面的显着特征，在气候和构造的共同影响下由隆起和侵蚀形成。河流沿其河道下降时的坡度如何变化——其纵向剖面凹度——从一个流域到另一个流域变化很大，反映了隆起和侵蚀过程之间的相互作用。最近的一项全球分析表明，气候干旱应该是对河流剖面凹度的一级控制，但气候相对于其他因素的重要性尚未在全球范围内得到检验。在这里，我们使用最近的全球气候、河流剖面和构造活动数据集表明，在河流剖面凹度的全球模式中，构造比气候更强烈地表达。河流剖面在沿板块边界的构造活动区域倾向于更强烈地凹入，反映了构造引起的抬升速率的空间变化。河流剖面凹度与四个全球构造代理（盆地平均河道梯度、到板块边界的距离和两个地震活动度量）之间的等级相关性比河流凹度和三个气候指标（降水量、潜在蒸散量和干旱度）之间的相关性要强得多。我们通过长期隆起和河流下切的简单概念模型来解释构造活动与河流剖面凹度增加之间的关联。这些结果表明，构造而非气候对全球河流纵向剖面的形状施加了主要控制。反映了构造引起的抬升率的空间变化。河流剖面凹度与四个全球构造代理（盆地平均河道梯度、到板块边界的距离和两个地震活动度量）之间的等级相关性比河流凹度和三个气候指标（降水量、潜在蒸散量和干旱度）之间的相关性要强得多。我们通过长期隆起和河流下切的简单概念模型来解释构造活动与河流剖面凹度增加之间的关联。这些结果表明，构造而非气候对全球河流纵向剖面的形状施加了主要控制。反映了构造引起的抬升率的空间变化。河流剖面凹度与四个全球构造代理（盆地平均河道梯度、到板块边界的距离和两个地震活动度量）之间的等级相关性比河流凹度和三个气候指标（降水量、潜在蒸散量和干旱度）之间的相关性要强得多。我们通过长期隆起和河流下切的简单概念模型来解释构造活动与河流剖面凹度增加之间的关联。这些结果表明，构造而非气候对全球河流纵向剖面的形状施加了主要控制。到板块边界的距离和两个地震活动测量值）比河流凹度和三个气候指标（降水量、潜在蒸散量和干旱度）之间的值要强得多。我们通过长期隆起和河流下切的简单概念模型来解释构造活动与河流剖面凹度增加之间的关联。这些结果表明，构造而非气候对全球河流纵向剖面的形状施加了主要控制。到板块边界的距离和两个地震活动测量值）比河流凹度和三个气候指标（降水量、潜在蒸散量和干旱度）之间的值要强得多。我们通过长期隆起和河流下切的简单概念模型来解释构造活动与河流剖面凹度增加之间的关联。这些结果表明，构造而非气候对全球河流纵向剖面的形状施加了主要控制。