By GARLAND KENNEDY
Sentinel Staff Writer
Sitka’s landslide detection and warning system remains in development, and continues to move forward, a number of the out-of-town experts on the project told the Sentinel Friday during a visit to Sitka.
“The mission of the project is to better predict landslides and to work with the community to inform hazards and risk awareness and response,” said Dr. Annette Patton, a postdoctoral geologist at the University of Oregon and one of the project leads.
“The main purpose of our visit last week was community outreach, including informal... meetings with city, tribal, and other officials,” said Dr. Robert Lempert, one of the project principals and director of the RAND Corporation’s Pardee Center. RAND is a national research and analysis think tank in Santa Monica, California.
The Sitka project dates from the Kramer Avenue landslide in 2015 which killed three people. The Kramer landslide served as a painful reminder of local landslide risks. The current project was initiated to track landslide risks to other developed areas of town and create a warning system.
Sitka Sound Science Center Director Lisa Busch said the purpose of last week’s visit was “meeting with community members, and reporting back on what they have been finding.”
Busch noted that one feature in particular makes the system being developed for Sitka unique.
“This is a community-based warning system, which is very unusual,” she said.
Geologist Robert Lempert, left, talks about a landslide warning system with Sitkans at the Backdoor Cafe Friday. Lempert is co-principal investigator on the Sitka Landslide Warning System project and other members of the project were in Sitka last week. The project is funded by the National Science Foundation’s Smart and Connected Community program. The $2.1 million project involves the RAND Corporation, the University of Southern California, Sitka Sound Science Center, Sitka Tribe of Alaska, the State of Alaska Division of Geologic and Geophysical Services, the National Weather Service and a host of other partners including the USDA Forest Service, the U.S Geologic Survey. (Sentinel Photo by James Poulson)
Recent technological advances have allowed the project to use affordable, portable moisture sensors on potential landslide slopes, which Busch said would allow a great number of sensors to eventually be deployed.
The project received a $2.1 million grant from the National Science Foundation’s Smart and Connected Communities program in late 2018.
“This project will improve understanding of how data can be used to facilitate a fair, accountable, integrative, and transparent risk management process,” the NSF website reads. The NSF says that the project will not only include science-based landslide warning and detection, but also lead to “an improved understanding of risk perception and communication.”
Local participants in the landslide detection and warning project include the Sitka Sound Science Center, Sitka Tribe of Alaska, and the U.S. Forest Service, among others.
“There’s been a lot of technology advance in very small, inexpensive moisture sensors, and they’ve been used in agriculture,” Lempert said.
Problems were detected with the early sensors for the project, he said, and third generation sensors will be installed this coming spring.
The three sensors now in place measure soil moisture, a critical factor since landslides occur when soil reaches very high water saturation, Patton said.
“It mostly comes down to the intensity of the rain, and how long it has been raining,” she said. Patton also noted that certain atmospheric effects can influence landslides.
“There are weather patterns called atmospheric rivers that deliver this really intense, long duration storms. And the majority of landslides... that initiate occur during these big columns of water storms coming into the coasts... The trick is trying to predict where they might land,” she said.
This landslide detection system being developed for Sitka is the very first of its type, and it is not yet operational, Lempert said. The project combines geophysical science with public policy. Lempert said that a crucial aspect of the project is the delivery method for a landslide warning message once the system is operational.
“One of the questions we need to address... is whether the best warning system is an official government warning... or whether Sitkans would really just prefer a dashboard, a computer map housed by some appropriate agency,” Lempert said.
He added that another question which needs addressing is “how do you build trust in the system, with different criteria of success?”
Referring to the Kramer Avenue landslide, he said, “Rain density surrounding that slide was pretty anomalous.” However, he added, “geographic specificity” of a warning may prove to be difficult.
RAND analyst Ryan Brown said that the warning system “is something that’s going to require some calibration... the human response, that’s the other variable.”
Brown and Lempert noted that the task of ensuring accurate and timely warning is difficult.
Brown said project members are looking at historical data as well. He said one of the project goals is “trying to learn about the deep Tlingit historical knowledge. And they found some old place names that sound like ‘landslide.’”
STA Resource Protection Director Jeff Feldpausch said that the Tribe has conducted citizen surveys, which uncovered no specific stories of landslides, but did reveal place names about “land that moved.”
Feldpausch added that further surveys would be used to gather community thoughts regarding a potential landslide warning system.
Interim city Administrator Hugh Bevan noted that trying to predict a landslide is very difficult, and could have unforeseen side effects.
He said that landslide risk maps have impacted mortgage and insurance markets, and hoped that this “unintended consequence” could be mitigated.
“Ideally,” said Patton, “we’re going to have the science and the communication framework to allow Sitkans to make choices about how they want to learn about risk, and how they want to be notified of hazardous conditions. And then once that’s established, the dream would be to help apply that to other communities.”
