Drainage basins are fundamental units of Earth's surface, describing how flows accumulate across landscapes. They are direct expressions of how tectonics and climatic forces alter Earth's surface morphology. Here, we measure the width-to-length ratios (WLRs) of 386,931 drainage basins (average area ∼157 km²), covering all continents except Antarctica and Greenland. Global variations in WLRs are correlated with climatic aridity, whole-basin slope, and local topographic roughness. Basins in arid landscapes tend to be narrower, potentially reflecting a higher prevalence of surface runoff and therefore a stronger slope-parallel component of the transporting flow. Local topographic roughness is associated with wider basins, potentially reflecting greater dispersion of flow directions. Conversely, whole-basin topographic gradients, potentially reflecting gradients in uplift, are associated with narrower basins. However, steeper basins are also often rougher, so revealing the effects of whole-basin slope requires correcting for the confounding effects of roughness variations.

中文翻译：

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地形和气候对流域形状控制的全球分析

排水盆地是地球表面的基本单位，描述了水流如何在景观中积累。它们是构造和气候力量如何改变地球表面形态的直接表达。在这里，我们测量了 386,931 个流域（平均面积~157 km ² ）的宽长比（WLR），覆盖除南极洲和格陵兰岛之外的所有大陆。 WLR 的全球变化与气候干旱、全流域坡度和局部地形粗糙度相关。干旱地区的盆地往往更窄，这可能反映出地表径流的发生率更高，因此输送流的坡面平行成分更强。局部地形粗糙度与较宽的盆地相关，可能反映了流向的更大分散。相反，整个盆地的地形梯度可能反映隆起的梯度，与较窄的盆地相关。然而，较陡的盆地通常也较粗糙，因此揭示整个盆地坡度的影响需要纠正粗糙度变化的混杂影响。