Banning developments in high risk landslide areas could significantly reduce devastation in earthquake pronecountries, engineers said this week.
The earthquake in southern Sumatra, Indonesia on 30 September caused landslides which killed hundreds of people and wiped out villages in the Purimain province.
The landslides also blocked roads making access difficult (News last week).
“The terrain is hilly and a lot of villages were affected by the landslides,” said Arup Seismic Group associate director Zygmunt Lubowski. “The question is: should they have been developed in those areas?
“You might not want to legislate over what people build but the local municipality could legislate where people could build. If you’re building under a slope, is it a safe place?”
But engineers said residents may be unwilling to relocate and there is a general lack of information on hazard locations.
“The terrain is hilly and a lot of villages were affected by the landslides. The question is: should they have been developed in those areas?”
Zygmunt Lubowski, Arup
“Various agencies have produced landslip hazard maps on a project or area basis but not systematically over the whole country with the intention of moving people to safer areas,” said Black & Veatch technical director for water resources in Asia David Meigh.
“Even with such maps it is unlikely that local government in Indonesia would act and move people from risky areas.”
Landslide risk is compounded by ignorance of good practice on slope stabilisation.
“In rural areas, poorer people build houses along the road edges especially where land ownership is not clear such as on ridges, across slopes and at the foot of slopes,” said Meigh. “Trees are often felled upslope to provide timber for houses and then burnt and clean weeded for annual crops leaving slopes more susceptible to landslip.”