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An extreme flood caused by a heavy snowfall over the Indigirka River basin in Northeastern Siberia |
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| Authors: | Shunsuke Tei Tomoki Morozumi Shin Nagai Shinya Takano Atsuko Sugimoto Ryo Shingubara Rong Fan Alexander Fedorov Tuyara Gavrilyeva Nikita Tananaev Trofim Maximov |
| Institution: | 1. Arctic Research Center, Hokkaido University, Sapporo, Japan;2. Arctic Research Center, Hokkaido University, Sapporo, Japan
Graduate School of Environmental Science, Hokkaido University, Sapporo, Japan Research Faculty of Agriculture, Hokkaido University, Sapporo, Japan;3. Earth Surface System Research Center & Institute of Arctic Climate and Environment Research, Research Institute for Global Change, Japan Agency for Marine-Earth Science and Technology, Yokohama, Japan;4. Graduate School of Environmental Science, Hokkaido University, Sapporo, Japan;5. Arctic Research Center, Hokkaido University, Sapporo, Japan Faculty of Environmental Earth Science, Hokkaido University, Sapporo, Japan Global Station for Arctic Research, Global Institution for Collaborative Research and Education, Hokkaido University, Sapporo, Japan Best (BiogeoscienceEducational and Scientific Training) Center, North-Eastern Federal University, Yakutsk, Russia;6. Graduate School of Environmental Science, Hokkaido University, Sapporo, Japan Graduate School of Environmental Studies, Nagoya University, Nagoya, Japan;7. Graduate School of Environmental Science, Hokkaido University, Sapporo, Japan Institute of Low Temperature Science, Hokkaido University, Sapporo, Japan;8. Best (BiogeoscienceEducational and Scientific Training) Center, North-Eastern Federal University, Yakutsk, Russia Melnikov Permafrost Institute, Siberian Branch of the Russian Academy of Sciences, Yakutsk, Russia;9. Department of Regional Economic and Social Studies, Yakutian Scientific Center, Siberian Branch of the Russian Academy of Sciences, Yakutsk, Russia Institute of Engineering and Technology, North-Eastern Federal University, Yakutsk, Russia;10. Melnikov Permafrost Institute, Siberian Branch of the Russian Academy of Sciences, Yakutsk, Russia;11. Best (BiogeoscienceEducational and Scientific Training) Center, North-Eastern Federal University, Yakutsk, Russia Institutefor Biological Problem of Cryolithozone, Siberian Division of Russian Academy of Science, Yakutsk, Russia |
| Abstract: | Flooding is one of the greatest disasters that produces strong effects on the ecosystem and livelihoods of the local population. Flood frequency is expected to increase globally making its risk assessment an urgent issue. In spring-summer 2017, an extreme flooding occurred in the Indigirka River lowland of Northeastern Siberia that inundated a large area. In this study, the extent and climatic drivers of the flooding were determined using the results of field observations, satellite images, and climate reanalysis dataset, and its possible effects on the ecosystem were discussed. In 2017, a significant lowland area of around 16,016 km2 was covered with water even in July, which was 5,217 km2 (around 4% of the total area) greater than the water-covered area in 2015 when usual hydrological condition in the area was observed. The hydrographic signature obtained for the Indigirka River water level in 2017 was unusual. Although the water level rose sharply at the end of May (which was typical for the Arctic region), it did not fall afterwards and even increased again to an annual daily maximum value in the middle of July. The climate reanalysis dataset obtained for the temporal–spatial variations of snow water equivalent, snowmelt, and runoff over the lowland revealed that a large amount of snowmelt runoff in June and July 2017 produced a large water-covered area and unusually high river water levels that lasted until summer. Snow depth from winter to spring was largest in 2017 over the period from 2009 to 2017, and the surface of the lower reach of the lowland was partially covered with snow even in the end of June due to the extreme snowfall that occurred in October 2016. Such unusual hydrological conditions waterlogged most trees over the lowland, which caused serious ecosystem devastation and changes in the material cycle. |
| Keywords: | extreme flooding Indigirka River lowland Northeastern Siberia material cycling water level snowfall |