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Causes of change in 20th century global river discharge
Author(s) -
Gerten Dieter,
Rost Stefanie,
von Bloh Werner,
Lucht Wolfgang
Publication year - 2008
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2008gl035258
Subject(s) - cru , precipitation , environmental science , climatology , global warming , water cycle , forcing (mathematics) , climate change , land cover , el niño southern oscillation , vegetation (pathology) , magnitude (astronomy) , discharge , physical geography , land use , geography , drainage basin , oceanography , geology , meteorology , ecology , cartography , medicine , physics , pathology , astronomy , biology
A global vegetation and hydrology model (LPJmL) was applied to quantify the contributions of changing precipitation, temperature, atmospheric CO 2 content, land use and irrigation to worldwide trends in 20th century river discharge (Q). Consistently with observations, Q decreased in parts of Africa, central/southern Asia and south‐eastern Europe, and increased especially in parts of North America and western Asia. Based on the CRU TS2.1 climatology, total global Q rose over 1901–2002 (trend, 30.8 km 3 a −2 , equaling 7.7%), due primarily to increasing precipitation (individual effect, +24.7 km 3 a −2 ). Global warming (−3.1), rising CO 2 (+4.4), land cover changes (+5.9) and irrigation (−1.1) also had discernible effects. However, sign and magnitude of trends exhibited pronounced decadal variability and differed among precipitation forcing datasets. Since recent trends in these and other drivers of Q are mainly anthropogenic, we conclude that humans exert an increasing influence on the global water cycle.