RiTiCE:River flow Timing Characteristics and Extremes in the Arctic region

• Main Authors: Jalali Shahrood, A. (Abolfazl), Ahrari, A. (Amirhossein), Rossi, P. M. (Pekka M.), Klöve, B. (Björn), Torabi Haghighi, A. (Ali)
• Format: Article in Journal/Newspaper
• Language: English
• Published: Multidisciplinary Digital Publishing Institute 2023
• Subjects: arctic region; flow timing; ice processes; river flow; river ice break-up; Arctic; Tana River; Tornio
• Online Access: http://urn.fi/urn:nbn:fi-fe20230925136318

Abstract (1) Background: river ice has a significant impact on nearly 66% of rivers in the Northern Hemisphere. Ice builds up during winter when the flow gradually reduces to its lowest level before the spring melt is initiated. Ice-induced floods can happen quickly, posing a risk to infrastructure, hydropower generation, and public safety, in addition to ecological repercussions from the scouring and erosion of the riverbeds. (2) Methods: we used the annual daily hydrograph to develop a RiTiCE tool that detects the break-up date and develops indices to analyze timing characteristics of extreme flow in the Tana and Tornio Rivers. (3) Results: the study showed that low-flow periods in two rivers had a significant trend with a confidence level of 95%. Additionally, it was observed that the occurrence date of seasonal 90-day low- and high-flow periods occurred earlier in recent years. Conversely, the Tana River showed a negative trend in its annual minimum flow over the century, which is the opposite of what happened with the Tornio River. (4) Conclusions: the method can be used to detect the date when the river ice breaks up in a given year, leading to a better understanding of the river ice phenomenon.