| 1. |
- Hou, Xuejiao, et al.
(författare)
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Global mapping reveals increase in lacustrine algal blooms over the past decade
- 2022
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Ingår i: Nature Geoscience. - : Springer Science and Business Media LLC. - 1752-0894 .- 1752-0908. ; 15:2, s. 130-134
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Tidskriftsartikel (refereegranskat)abstract
- Algal blooms constitute an emerging threat to global inland water quality, yet their spatial and temporal distribution at the global scale remains largely unknown. Here we establish a global bloom database, using 2.91 million Landsat satellite images from 1982 to 2019 to characterize algal blooms in 248,243 freshwater lakes, representing 57.1% of the global lake area. We show that 21,878 lakes (8.8%) spread across six continents have experienced algal blooms. The median bloom occurrence of affected lakes was 4.6%, but this frequency is increasing; we found increased bloom risks in the 2010s, globally (except for Oceania). The most pronounced increases were found in Asia and Africa, mostly in developing countries that remain reliant on agricultural fertilizer. As algal blooms continue to expand in scale and magnitude, this baseline census will be vital towards future risk assessments and mitigation efforts.
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| 2. |
- Nie, Junsheng, et al.
(författare)
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Rapid incision of the Mekong River in the middle Miocene linked to monsoonal precipitation
- 2018
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Ingår i: Nature Geoscience. - : Springer Science and Business Media LLC. - 1752-0894 .- 1752-0908. ; 11, s. 944-948
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Tidskriftsartikel (refereegranskat)abstract
- The uplift of orogenic plateaus has been assumed to be coincident with the fluvial incision of the gorges that commonly cut plateau margins. The Mekong River, which drains the eastern Qiangtang Terrane and southeastern Tibetan Plateau, is one of the ten largest rivers in the world by water and sediment discharge. When the Mekong River was established remains highly debated-with estimates that range from more than 55 to less than 5 million years ago-despite being a key constraint on the elevation history of the Tibetan Plateau. Here we report low-temperature thermochronology data from river bedrock samples that reveal a phase of rapid downward incision (>700 m) of the Mekong River during the middle Miocene about 17 million years ago, long after the uplift of the central and southeastern Tibetan Plateau. However, this coincides with a period of enhanced East Asian summer monsoon precipitation over the region compared with the early Miocene. Using stream profile modelling, we demonstrate that such an increase in precipitation could have produced the observed incision in the Mekong River. In the absence of an obvious tectonic contribution, we suggest that the rapid incision of the Tibetan Plateau and the establishment of the Mekong River in the middle Miocene may be attributed to increased erosion during a period of high monsoon precipitation.
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