Global extent of rivers and streams.

Area of Science:

• Geosciences
• Environmental Science
• Hydrology

Background:

• Rivers and streams are critical sites for biogeochemical exchange between Earth's surface and the atmosphere.
• Accurate estimates of the global fluvial network's surface area are essential for understanding land-atmosphere trace gas fluxes, such as carbon dioxide.
• Previous spatial estimates of river and stream surface area are poorly constrained.

Purpose of the Study:

• To quantify the total surface area of the global river and stream network.
• To reassess the contribution of rivers and streams to global biogeochemical cycles.
• To improve global carbon budget estimations.

Main Methods:

• Utilized a global database of river planform hydromorphology.
• Applied a statistical approach to estimate surface area at mean annual discharge.
• Compared new estimates with previous spatial data.

Main Results:

• The global river and stream surface area is estimated at 773,000 ± 79,000 square kilometers (0.58 ± 0.06% of Earth's nonglaciated land surface).
• This represents a 44 ± 15% increase compared to previous spatial estimates.
• The findings indicate a potentially larger role for rivers and streams in controlling land-atmosphere fluxes.

Conclusions:

• The total surface area of the world's rivers and streams is significantly underestimated.
• Rivers and streams are likely more influential in global biogeochemical cycles than currently accounted for in global carbon budgets.
• Revised estimates are crucial for accurate climate and carbon cycle modeling.