Carbon export by rivers draining the conterminous United States

Inland Waters
By:  and 

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Abstract

Material exports by rivers, particularly carbon exports, provide insight to basin geology, weathering, and ecological processes within the basin. Accurate accounting of those exports is valuable to understanding present, past, and projected basin-wide changes in those processes. We calculated lateral export of inorganic and organic carbon (IC and OC) from rivers draining the conterminous United States using stream gaging and water quality data from more than 100 rivers. Approximately 90% of land area and 80% of water export were included, which enabled a continental-scale estimate using minor extrapolation. Total carbon export was 41–49 Tg C yr−1. IC was >75% of export and exceeded OC export in every region except the southeastern Atlantic seaboard. The 10 largest rivers, by discharge, accounted for 66% of water export and carried 74 and 62% of IC and OC export, respectively. Watershed carbon yield for the conterminous United States was 4.2 and 1.3 g C m−2 yr−1 for IC and OC, respectively. The dominance of IC export was unexpected but is consistent with geologic models suggesting high weathering rates in the continental United States due to the prevalence of easily weathered sedimentary rock.

Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Carbon export by rivers draining the conterminous United States
Series title Inland Waters
DOI 10.5268/IW-2.4.510
Volume 2
Year Published 2012
Language English
Publisher International Association of Theoretical and Applied Limnology
Publisher location Stuttgart
Contributing office(s) National Research Program - Central Branch
Description 8 p.
First page 177
Last page 184
Online Only (Y/N) N
Additional Online Files (Y/N) N