Long term trends in seasonal specific discharges for selected Alaskan rivers

• Main Author: McClellan, Calvin A
• Format: Text
• Language: unknown
• Published: UVM ScholarWorks 2021
• Subjects: climate change; hydrology; discharge; changing seasonality; arctic; climate warming; Honors College; Arctic; Climate change; Alaska
• Online Access: https://scholarworks.uvm.edu/hcoltheses/420; https://scholarworks.uvm.edu/context/hcoltheses/article/1476/viewcontent/auto_convert.pdf

As global climate warming has occurred, the arctic and sub-arctic regions have begun to see changes in surface water transport, both in terms of seasonal patterns and total discharge [Dornblaser and Striegl, 2007; Walvoord and Striegl, 2007]. While it is known that discharge has been increasing in the arctic, the exact timing of this trend is less well-documented. This study carried out analysis on 24 sites across Alaska using long-term USGS monthly records to identify trends that have emerged for each month of the year as well as regional variations. Across all sites, 45.8% of all months have had a significant change in specific discharge. The Arctic Slope and Southwest regions had the most statistically significant changes. In many sites, specific discharge has increased in May and decreased in June, indicating an earlier spring runoff season. Across all regions, specific discharge has increased in the fall and winter. Specific discharge records were broken at the year 2000 into an early and late group, which were compared. This revealed that December was the month in which most rivers exhibited changing seasonality, although almost half the sites had significant change in January, February, and April as well. In terms of regional differences, the Southwest and Arctic Slope regions had the highest percentage of statistical significance, however almost all regions were fairly similar.