Satel­lites may warn of killer land­slides

China Daily (Hong Kong) - - TOP NEWS - By AN­GUS MCNEICE in Lon­don an­gus@mail.chi­nadai­

Re­searchers in China and the United King­dom hope to use satel­lite imag­ing for the early de­tec­tion of land­slides in South­west China, such as the one in late June that en­gulfed a vil­lage in Maox­ian county, Sichuan province, leav­ing at least 10 dead and 73 miss­ing.

A team of re­searchers from the UK’s New­cas­tle Univer­sity and sev­eral Chi­nese in­sti­tu­tions an­a­lyzed be­fore and after satel­lite im­ages of the Maox­ian re­gion that show the dan­ger area had been mov­ing at a slow pace for at least six months be­fore fail­ing com­pletely.

The team iden­ti­fied 10 other ac­tive l and­slides i n the re­gion and for­warded the in­for­ma­tion to au­thor­i­ties.

“When you con­sider this sort of time scale, it sug­gests that a landslide early-warn­ing sys­tem is not only pos­si­ble but would also be ex­tremely ef­fec­tive,” Li Zhen­hong, pro­fes­sor of imag­ing geodesy at New­cas­tle Univer­sity, said.

Brought on by heavy rain­fall, the Maox­ian landslide swept through homes in the vil­lage of Xinmo and buried a 1.6 kilo­me­ter sec­tion of road un­der an es­ti­mated 8 mil­lion cu­bic me­ters of rub­ble. A sec­ond landslide hit the vil­lage three days later, and a third also struck Shidaguan, a town 20 km away.

“If we can de­tect move­ment at a very early stage,” Li said, “then in many cases it is likely we would have time to put sys­tems in place to save lives.”

Re­searchers from Chengdu Univer­sity of Tech­nol­ogy, Tong ji Univer­sity, the China Academy of Space Tech­nol­ogy and Wuhan Univer­sity, par­tic­i­pated in the study. They an­a­lyzed im­ages cap­tured by the Euro­pean Space Agency’s Sentinel-1 satel­lite radar mis­sion, com­posed of two po­lar-or­bit­ing satel­lites, that op­er­ate day and night in all weather con­di­tions.

Sichuan is fre­quently dis­rupted by tre­mors.

In 2008, one of the most dev­as­tat­ing earth­quakes in China’s his­tory struck the province, claim­ing more than 69,000 lives.

The team hopes to use the tech­nol­ogy to build a landslide data­base, map­ping ac­tive land­slides in Sichuan and other seis­mi­cally ac­tive re­gions of South­west China.

“Go­ing for­ward, we can use this in­for­ma­tion to set up real-time mon­i­tor­ing sys­tems us­ing ex­ist­ing satel­lites such as GPS, Bei­dou and Galileo for those sites and when­ever we de­tect ab­nor­mal be­hav­ior, the sys­tem can send out an ear­ly­warn­ing mes­sage,” Li said.

Land­slides are among the most com­mon nat­u­ral dis­as­ters.

More than 20,000 peo­ple were killed by more than 7,000 rain­fall-caused land­slides recorded around the world be­tween 2007 and 2015, ac­cord­ing to NASA’s Global Landslide Cat­a­log.


Mil­i­tary bands from many coun­tries play at the In­ter­na­tional Mil­i­tary Tat­too show at Hong Kong Coli­seum on Thurs­day. The show, in­volv­ing 13 mil­i­tary bands, in­clud­ing that from the Peo­ple’s Lib­er­a­tion Army Hong Kong Gar­ri­son, is to mark the 20th an­niver­sary of Hong Kong’s re­turn to the moth­er­land. It’s open to the pub­lic un­til Satur­day.

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