NASA主導の研究により、地球の河川に関する新たな地球規模の計算が示される(NASA-Led Study Provides New Global Accounting of Earth’s Rivers)


2024-04-29 NASA



滞留時間に依存する河川貯水のグローバルパターン Global patterns in river water storage dependent on residence time

Elyssa L. Collins,Cédric H. David,Ryan Riggs,George H. Allen,Tamlin M. Pavelsky,Peirong Lin,Ming Pan,Dai Yamazaki,Ross K. Meentemeyer & Georgina M. Sanchez
Nature Geoscience  Published:22 April 2024

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Accurate assessment of global river flows and stores is critical for informing water management practices, but current estimates of global river flows exhibit substantial spread and estimates of river stores remain sparse. Estimates of river flows and stores are hampered by uncertainties in land runoff, an unobserved quantity that provides water input to rivers. Here we leverage global river flow observations and an ensemble of land surface models to generate a globally gauge-corrected monthly river flow and storage dataset. We estimate a global river storage mean (± monthly variability) of 2,246 ± 505 km3 and a global continental flow of 37,411 ± 7,816 km3 yr−1. Our global river water storage time series demonstrates that flow wave residence time is a fundamental driver that can double or halve river water stores and their variability. We also reconcile the wide range in previous estimates of monthly variability in global river flows. We identify previously underappreciated freshwater sources to the ocean from the Maritime Continent (Indonesia, Malaysia and Papua New Guinea) amounting to 1.6 times the Congo River and illustrate our capability of detecting severe anthropogenic water withdrawals.