Landslide Impacts Can Be Reduced
More landslides can be expected as climate change exacerbates rainfall intensity – but their impact can be reduced, stresses the UN organization charged with coordinating global disaster risk reduction.
"As this week's tragic events in East Asia show once again, people living on unstable slopes and steep terrains are particularly at risk from landslides in the wake of torrential rain and flooding," says Margareta Wahlström who heads the UN International Strategy for Disaster Risk Reduction (UNISDR). "While landslides are hard to predict, people living in landslide-prone areas can be alerted in advance if there are monitoring and warning systems in place to measure rainfalls and soil conditions."
Such action is essential with the Intergovernmental Panel on Climate Change predicting more intense rainfalls in the future, leading to increased instability of slopes and making more people vulnerable to landslides. Population growth and urbanization of steep hillsides will add to the problem.
UNISDR points to a number of examples where sound and sustainable preventive measures have demonstrably reduced landslide impact:
In Hong Kong, which has a long history of death and destruction wreaked by landslides, a 'Slope Safety System' introduced by the Government in the mid-1970s has resulted in a 50% fall in the casualty rates from landslides on the 1977 level, targeting a further reduction – to 75% – by 2010. Measures focus on protective and remedial work, monitoring and early warning and a wide-ranging education program and provide a comprehensive "risk reduction" approach combining science, engineering works and public outreach.
Following a landslide in August 2002 in Orosi de Cartago, the Costa Rican Red Cross implemented an early warning system to mitigate future events. Some 200 people were trained in disaster preparedness and 30 community members received basic training as radio operators. Nine months after this disaster, another landslide occurred but this time the local response was more proactive and helped saved many people.
The Hyogo Framework for Action (HFA), a ten year plan to reduce all types of disaster risks, signed by 168 Governments in 2005, encourages local authorities to identify landslide risk and vulnerabilities, establish hazard maps and put in place effective monitoring systems. It also recommends implementing protective engineering works, urban planning strategies, environmental management and community preparedness.
“Landslides are a growing problem in many countries, but, as these examples show, people living in landslide-prone areas can be better protected” adds Wahlström, who is also the Special Representative of the UN Secretary-General for Disaster Risk Reduction. “More action is needed to reduce disaster risks and avoid losses and HFA provides the direction on how to do so.”