Flow regime alteration in Arctic rivers due to dam operations and climate change.

Arctic rivers and water resources currently experience significant hydrological changes due to climate change and global warming. The flow regime alteration in Arctic rivers strongly influences the conservation and sustainability of the native biodiversity of the riverine ecosystem. The change in major characteristics of the daily and monthly flow regime of seven arctic rivers has been assessed in this study. The daily flow (40–120 years) at the outlet of Lena River, Yenisey River, Kolyma River, and Ob' River in Russia; Yukon River in the USA; Mackenzie River in Canada; and Tana River, Norway was used. Except for the Tana River, the rest of these rivers have been regulated. In addition, monthly flow alteration in the headwater of these rivers and below sixteen dams was assessed. In this research, we applied 'Indicator of Hydrologic Alteration' (IHA) and 'River Impact' (RI) methods to estimate daily monthly flow change in the river. Based on the daily analysis, the most significant change was observed for Yenisey and Ob rivers. The Kolyma hydropower shows the lowest impact, while the Shushenskaya Dam on Yenisey shows the highest impact on the flow regime. • The flow regime variation of seven major arctic rivers was analyzed. • The impact of 16 dams on the flow regime of the major arctic rivers was studied. • Winter streamflow of Arctic rivers increased significantly over the past 40 years. • The Shushenskaya dam on the Yenisey river showed the highest impact on flow regime. [ABSTRACT FROM AUTHOR]