| Autor: |
Vu, Tinh, Kiesel, Jens, Guse, Björn, Domisch, Sami, Fohrer, Nicola |
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| Zdroj: |
Earth's Future; Dec2024, Vol. 12 Issue 12, p1-19, 19p |
| Abstrakt: |
Global discharge regimes are strongly affected by multiple environmental drivers. It remains a challenge to relate their contributions and complex spatio‐temporal cause‐effect chains to a given time and location. To disentangle these relationships, we combined 12 environmental variables with changes in more than 25,000 discharge time series globally and identified the variable importance across climate zones using random forest analyses. The results show that (a) about two‐thirds of the global catchments experienced significant changes in discharge between 1980s and 1990s and (b) more than 80% of the basins with new dams built during the study period have experienced changes, twice as many as basins without dams. Furthermore, (c) most environmental variables were subject to significant changes, especially precipitation, temperature and urban land cover; (d) strong changes in the discharge regime were mostly associated with precipitation, followed by land cover changes, and (e) impacts of water infrastructure are dominant in basins with weak evidence of change in discharge. Our findings highlight the contribution of each individual environmental factor on global discharge regimes and can be used to inform water‐related studies and global modeling efforts in the future. Plain Language Summary: Understanding how environmental conditions contribute to changes in discharge of rivers is important for river basin management. This is relevant on the global scale, particularly against the background of land use and climate change that is caused by anthropogenic activities. Our study considers both environmental conditions that change over time (dynamic) and those that differ only spatially (static) to investigate their connection to changes in discharge from 1960 to 2010 at global scale. We show that a transition in the discharge regime has occurred in two‐third of the rivers globally between 1980s and 1990s. All environmental factors have jointly contributed to these changes, but are not equally important. Overall, precipitation and land cover are most important drivers of changes in discharge. Other anthropogenic factors such as dams, water use and irrigation have a secondary impact and are related to weak changes in discharge and where precipitation and land cover are less important. Our findings can explain the interconnection between water, climate, human activities and natural geographic properties and provide information for improving future resources management and planning. Key Points: Two‐thirds of more than 25,000 global rivers in period 1960–2010 suffer significant changes in the 1980s–1990sMultiple environmental variables affect discharge regimes at a continental and global scale in space and timeA combination of statistical methods and machine learning techniques is beneficial for future studies [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
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