Interdisciplinary approach to hydrological hazard mitigation and disaster response and effects of climate change on the occurrence of flood severity in central Alaska

Abstract

Abstract. In May 2013, a massive ice jam on the Yukon River caused flooding that destroyed much of the infrastructure in the Interior Alaska village of Galena and forced the long-term evacuation of nearly 70 % of its residents. This case study compares the communication efforts of the out-of-state emergency response agents with those of the Alaska River Watch program, a state-operated flood preparedness and community outreach initiative. For over 50 years, the River Watch program has been fostering long-lasting, open, and reciprocal communication with flood prone communities, as well as local emergency management and tribal officials. By taking into account cultural, ethnic, and socioeconomic features of rural Alaskan communities, the River Watch program was able to establish and maintain a sense of partnership and reliable communication patterns with communities at risk. As a result, officials and residents in these communities are open to information and guidance from the River Watch during the time of a flood, and thus are poised to take prompt actions. By informing communities of existing ice conditions and flood threats on a regular basis, the River Watch provides effective mitigation efforts in terms of ice jam flood effects reduction. Although other ice jam mitigation attempts had been made throughout US and Alaskan history, the majority proved to be futile and/or cost-ineffective. Galena, along with other rural riverine Alaskan communities, has to rely primarily on disaster response and recovery strategies to withstand the shock of disasters. Significant government funds are spent on these challenging efforts and these expenses might be reduced through an improved understanding of both the physical and climatological principals behind river ice breakup and risk mitigation. This study finds that long term dialogue is critical for effective disaster response and recovery during extreme hydrological events connected to changing climate, timing of river ice breakup, and flood occurrence in rural communities of the Far North.

Trends in the Timing and Magnitude of Ice-Jam Floods in Canada

“…The economic cost of IJFs in North America is estimated to be USD 300 million in 2017 17 . However, these existing approximations could be seriously underestimated considering single IJF events have been known to result in hundreds of millions of dollars in financial damages 1 such as the 2001 IJF in eastern Russia 18 , the 1996 IJF in Susquehanna River Basin in United States 19 and the recent IJF event at the interior Alaskan village of Galena in 2013 20 . Moreover, the current estimates account only for tangible monetary costs and do not reflect other serious implications such as residents’ relocation and even loss of life 21 .…”

Springtime Flood Risk Reduction in Rural Arctic: A Comparative Study of Interior Alaska, United States and Central Yakutia, Russia

“…Extreme changes in local air temperatures played a key role in the severity of the 2013 flood in Galena [5]. April and early May 2013 were the coldest since 1924 at all long-term observation stations in Interior Alaska.…”

“…In both communities, floodwaters and ice floes destroyed or severely damaged over 90 percent of homes and key infrastructure, resulting in multimillion-dollar damage [5,6]. Although extreme, the 2013 floods were not isolated instances in either community.…”

“…As a result, several ice jams formed along the middle reaches of the Yukon. The ice jam at Bishop Rock was so strong that it held for three days, backing the floodwaters and ice debris almost 30 km upstream to Galena, and 20 km beyond [5].…”

“…If the flood exceeds the state's resources, the governor requests a federal disaster declaration, and support. This succession significantly delayed relief and recovery efforts in Alaska 2013; over half of Galena's population remained in a two-years-long evacuation [5,6].…”