Department of Geological Sciences, University of North Carolina, Chapel Hill, NC, USA.
Science. 2018 Aug 10;361(6402):585-588. doi: 10.1126/science.aat0636. Epub 2018 Jun 28.
The turbulent surfaces of rivers and streams are natural hotspots of biogeochemical exchange with the atmosphere. At the global scale, the total river-atmosphere flux of trace gasses such as carbon dioxide depends on the proportion of Earth's surface that is covered by the fluvial network, yet the total surface area of rivers and streams is poorly constrained. We used a global database of planform river hydromorphology and a statistical approach to show that global river and stream surface area at mean annual discharge is 773,000 ± 79,000 square kilometers (0.58 ± 0.06%) of Earth's nonglaciated land surface, an area 44 ± 15% larger than previous spatial estimates. We found that rivers and streams likely play a greater role in controlling land-atmosphere fluxes than is currently represented in global carbon budgets.
河流和溪流的动荡表面是与大气进行生物地球化学交换的自然热点区域。在全球范围内，痕量气体（如二氧化碳）的总河-气通量取决于被河流网络覆盖的地球表面的比例，但河流和溪流的总表面积却受到很大限制。我们使用了一个全球平面河流水文学数据库和一种统计方法，表明在平均年径流量下，全球河流和溪流的表面积为 773,000 ± 79,000 平方公里（0.58 ± 0.06%），占地球非冰川陆地表面的面积，比以前的空间估计值大 44 ± 15%。我们发现，河流和溪流可能在控制陆地-大气通量方面发挥着比目前全球碳预算中更大的作用。
