New research uses 130 years of historic flood observations to help identify future risks

An ATV driver splashes their measurement done floodwaters on nan Kuskokwim River shoreline successful Bethel, Alaska connected Sept. 17, 2022. (MaryCait Dolan/KYUK)

Residents of low-lying villages successful Alaska cognize precisely wherever their communities are astir prone to flooding, but that accusation hasn’t ever been accessible connected a wider scale. New investigation helps compile much than 130 years of on-the-ground flood observations to thief communities and extracurricular agencies hole for and foretell early floods.

As autumn large wind play looms, truthful do storm-driven floods. Seventy-six percent of storm-driven floods successful Western and Northern Alaska hap betwixt September and November.

This year, successful August alone, 9 abstracted storms person pummeled nan Yukon-Kuskokwim Delta successful an incredibly early commencement to autumn large wind season. Mid-month, a series of 3 storms flooded homes, boardwalks and substance tanks passim nan Kuskokwim Delta seashore and up nan Kuskokwim River. The highest summertime upwind velocity since astatine slightest nan 1970s was recorded connected Aug. 16 astatine nan Bethel Airport.

“It’s been a privilege connected my database for a agelong clip to amended flood mapping successful Alaskan villages,” said geologist Rich Buzard, who useful for the United States Geological Survey, which is focused connected flooding and erosion. “Most villages successful Alaska don’t person capable flood mapping, essentially, and that has led to respective scenarios wherever flood mentation wasn’t arsenic bully arsenic it could person been and communities person suffered.”

Buzard was nan lead writer of a University of Alaska Fairbanks study published earlier this twelvemonth that looks astatine flood risk in communities on nan occidental and bluish coasts of Alaska by compiling and analyzing a database of hundreds of written accounts and observations going backmost to nan precocious 1880s.

Front Street successful Nome, Alaska during a large wind successful Oct. 1913.

“The situation was that successful today’s property of mapping, and numbers, and models, and things, that accusation wasn’t translated into nan connection we usage now,” Buzard said. “And truthful a batch of my activity was gathering these observations, uncovering retired nan truth: which flood is really nan highest, what benignant of impacts did it cause? Where did nan h2o go? And past doing nan mathematics connected really precocious that h2o is and wherever we put it connected a map.”

There are 2 cardinal issues nan task tries to address. The first is that communities haven’t really been capable to usage aliases entree their historical information erstwhile doing organization readying aliases successful identifying existent and early flood risks.

“In my acquisition moving connected flooding and erosion successful Alaska and past sharing nan results successful communities, a batch of times nan consequence I get is like, ‘Hey, this seems really meticulous to what we’ve been saying. It benignant of validates our claims,’” Buzard said. “Communities usage that accusation successful task proposals and planning. Evidence, scientifically-backed evidence, goes a agelong measurement to getting a connection approved. So I’m hoping that this type of activity tin thief communities scheme efficaciously and get things done, and hopefully move things guardant successful a measurement that possibly they’ve had roadblocks successful nan past.”

The 2nd rumor is to cod scattered flood information from astir nan region successful 1 spot truthful that it tin beryllium useful for agencies looking astatine floods and flood risks connected a much location scale. Buzard said that nan investigation recovered that from Bristol Bay to nan North Slope, location are astir 2,000 structures that presently beryllium successful what’s called nan grounds floodplain, places wherever nan highest recorded flood has touched before. The Bethel Census Area, which encompasses nan Kuskokwim seashore to acold up nan Kuskokwim River, has nan astir structures successful nan grounds floodplain of immoderate portion of nan study area.

“With oversea level rise, that conscionable benignant of increases nan baseline,” Buzard said. “And truthful complete time, smaller flood levels tin go much frequent. And if a grounds flood were to come, it whitethorn person a higher chance of exceeding a erstwhile record.“

In bid to hole for early storm-driven flooding, Buzard said that communities request to cognize precisely really overmuch of an rumor oversea level emergence mightiness be.

“The oversea level emergence projections that are retired now – by conscionable adding those to nan existent grounds flood level, past by 2100 we’re seeing astir 20% to 30% much structures successful nan floodplain than what we person today,” Buzard said.

As communities turn and build progressively costly infrastructure, Buzard said that taking flood risks into relationship becomes moreover much important.

“I deliberation that nan large displacement that needs to hap is much thought astir flood risk, basically, successful readying and organization development,” Buzard said. “And truthful that’s what we’re trying to create is tools, flood devices that group tin usage to make those plans truthful that our communities successful nan adjacent 50 years won’t beryllium facing nan risks that we’re dealing pinch today.”

Buzard said that nan investigation is simply a stepping chromatic for ongoing and early efforts by USGS, Alaska State Coastal Hazards Program, National Oceanic and Atmospheric Administration and nan National Weather Service to beforehand flood mapping successful Alaska.

“There’s a batch of activity being done to amended flood mapping and incorporated ambiance alteration into that, and each of that activity is supported by organization observations,” Buzard said.

Some of that activity involves trying to bring Alaska into USGS’s Coastal Storm Monitoring System, which tin thief foretell coastal flooding and erosion. It’ll besides see further organization surveys of precisely what parts of structures are nether threat from early floods. Many structures successful Western and Northern Alaska are elevated supra nan ground. To understand flood vulnerability successful a much elaborate way, Buzard said that he’ll person to study those first-floor elevations.

There’s besides much activity to beryllium done pinch Buzard’s database of historical flood impacts. Right now, a batch of nan information is successful spreadsheets.

“For individual communities, they’re going to request nan map, right?” Buzard said. “They’re still going to request discourse for really oversea level emergence could effect them.”

Buzard said that Typhoon Merbok, which deed Alaska’s westbound seashore successful 2022, near him scrambling to quickly nutrient maps that could place flood risks. He had conscionable vanished nan preliminary activity for nan project. And past successful immoderate communities, Typhoon Merbok met aliases exceeded nan grounds flood level.

“If different ample large wind for illustration that happens, we’re going to person a batch much devices and maps disposable truthful I don’t person to do that, like, overnight,” Buzard said pinch a laugh. “It’ll already beryllium done, is my goal.”

Ultimately, Buzard said that this activity is simply a testament to nan value of organization monitoring and observations.

“When you publication nan news reports and technological publications, they ever talk astir really Alaska doesn’t person very overmuch information and that makes things very challenging, and truthful this activity is demonstrating really we tin get complete that challenge,” Buzard said. “I person a flood history of complete 100 years based connected organization observations, and we proceed to usage those each nan time.”

And that database continues to grow, successful portion acknowledgment to a caller avenue for organization flood monitoring: a backstage flood observations Facebook page monitored by nan Alaska State Coastal Hazards Program, NWS and Buzard astatine USGS.