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Southeast Alaska's unique drought impacts cataloged

November 9, 2020

Caption: Southeast Alaska Panhandle towns like Ketchikan turned to diesel-generated power when hydropower reservoirs dropped to critically low levels during the 2017-2018 drought. Region-specific impacts have been added to the Drought Impacts by State tables available at droughtmonitor.unl.edu. Eric Jackson, Pixabay

Drought looks different across the country, and in 2019 the National Drought Mitigation Center added tables to the U.S. Drought Monitor that provides specific examples of how different levels of drought look for each state. During extreme drought (D3) in Iowa, seasonal allergies are worse and farmers might develop stress about high feed prices. During moderate drought (D1) in Maine, honey production tends to decrease. In southeast Alaska, there wasn’t that much specific information, because the research was based on a period of time when the region hadn’t experienced many droughts.

Then the winter of 2017-2018 happened.  

During that time, southeast Alaska experienced its most significant wet season drought event in over 40 years. Less than half of normal winter precipitation fell across some Panhandle towns. Ketchikan, Wrangell, Petersburg and other communities in the region turned to diesel-generated power as hydropower reservoirs dropped to critically low levels. Fish hatcheries and aquatic life suffered as water levels plummeted to record lows.  

Impacts like those are reflected in one of the first major updates to the USDM’s Drought Impacts by State tables, which now include Southeast Alaska-specific impacts based upon a collaborative research effort to describe what drought looks like in Southeast Alaska’s temperate rainforest ecosystem.  

“Because the recent drought was the most significant drought in a generation, many were not aware what drought looked like or how bad it could get,” NDMC climatologist Deborah Bathke said. “By linking impacts to drought severity, the new region-specific table provides a more complete characterization of drought, which in turn can help increase public awareness, inform management efforts and improve drought early warning.” 

The update follows a 2019 conference in Juneau, during which more than 80 participants representing local government, Alaska Native communities, state and federal agencies, nongovernmental organizations, academia, businesses, utilities and media gathered to improve understanding of what constitutes a drought in Southeast Alaska, where 100 inches of annual rainfall is considered abnormally low. As part of a U.S. Department of Agriculture Cooperative Agreement, the workshop organizers — including members from the NDMC, USDA Northwest Climate Hub, National Weather Service Forecast Office in Juneau, Alaska Center for Climate Assessment and Policy and the National Centers for Environmental Information — began a research effort designed to improve the impact table.  

The research project expanded upon the work of former NDMC research assistant Mary Noel, who developed localized impact tables for the 50 states and Puerto Rico. The project was aimed at helping both users and authors of the USDM understand what levels of drought severity look like in specific areas, and it was built to evolve once more ground level information became available.  

The initial Southeast Alaska impact table was based on one drought event. The updated table was based upon all drought periods for which impact information could be found, said Bathke, who attended the Juneau conference with NDMC climatologist Curtis Riganti and intern Jenna McCoy and was a lead collaborator on the project with USDA Northwest Climate Hub Coordinator Holly Prendeville. The researchers scoured the Drought Impact Reporter, scientific journal articles, media reports, social media feeds and community records to find happened in the area during previous droughts.  

The research project led to a set of 18 drought impacts that are likely to develop during periods of abnormal dryness (D0), moderate drought (D1), severe drought (D2), extreme drought (D3) and exceptional drought (D4). The two impacts listed in D4 are hypothetical, as the USDM has not yet designated a period of exceptional drought in the region.