Between 1981 and 2000, Central and South America were the areas in the world with the highest number of fatalities caused by natural disasters. The region accounted for over 100,000 deaths, more than 90 percent of the total recorded fatalities worldwide. Damage was estimated at a cost of around $24.2 billion, according to the Landslide Observatory in the Joint Center for Earth Systems Technology at the University of Maryland and the International Landslide Centre at the University of Durham in the United Kingdom.
At a recent IDB seminar on landslide hazards, experts Mark Bulmer and David Petley highlighted the region’s vulnerability to natural disasters, particularly landslides. However, they noted that falls, flows and slides are predictable and that an entire range of natural hazards can be mitigated.
Bulmer and Petley presented a measure-movement model for slopes that can be used to reduce risk in the region. Most landslides undergo small amounts of movement prior to final collapse. Their model allows these movements to be analyzed and permits predictions of future behavior to be made, according to a statement by the Geological Society of America . “Importantly, for the dangerous progressive failures, the model allows accurate prediction of the time of final collapse and the type of movement that will then occur,” Petley said. “Thus, for the first time, it is possible to predict when a catastrophic landslide will happen, which can form the basis of warning systems and better mitigation strategies.”
Tailored solutions range from reforestation in areas of low movement rate to drainage and terracing where the problems were more acute. The use of bioengineering is important, they said, especially where slopes have been cut for road infrastructure.
Sometimes it is difficult to identify where to focus the risk management, but it makes sense to pay attention to known risks, such roads located on high valleys, areas where human activity has disrupted coastlines, and deforested areas, Bulmer and Petley noted. They have also found a correlation between deserts, volcanic areas and landslide susceptibility, while areas with more forestation are less susceptible to landslides. “The situation is more complex than what people believe,” they say.
The experts noted that there has been an increase in the frequency of landslides since 2000, with most of them occurring in the region. And the causes are not just related to geography or environmental factors, such a global warming; they include human activity such as unauthorized mining projects, inappropriately constructed roads, and lack of awareness on the part of the local government, among the factors that increase the region's vulnerability.
“An important part of the work ahead,” said Bulmer, “is to develop search options with agencies in participating countries, plan research projects, collect data and disseminate the results through workshops and the local media.”
Heightening local awareness on landslide hazards
Too often, poverty and human need conspire with nature to increase the destruction from natural disasters in the region. Flimsy houses, poorly constructed roads and bridges, deforestation along riverbanks, on hills and in wooded areas, and human settlements along river basins all multiply the risk factors in Latin America and the Caribbean.
The IDB is working to help its member countries reduce their environmental risks. On March 1-3, the IDB launched a campaign, titled “When disaster strikes” (“Para el día que nos toque”), to raise local awareness about the risks from natural disasters in Costa Rica, Guatemala and Honduras. The campaign is going to raise awareness through commercial spots and fact sheets to workshops, forums and activities on risk prevention, among other methods to target national and local authorities, mass communications and citizens. The campaign's message is: let's invest, let's plan and let's take action today so we don't regret it tomorrow, when the next disaster hits.
“This awareness initiative is the fruit of an alliance between the Bank, the Coordination Center for Disaster Prevention in Central America (Centro de Coordinación para la Prevención de Desastres para América Central—CEPREDENAC) and the Municipal Federation of the Central American Isthmus (Federación de Municipios del Istmo Centroamericano—FEMICA). It is making it very clear that we all need to take responsibility for preventing and reducing the impact of natural phenomena,” said IDB external relations advisor Mirna Liévano de Marques during the campaign launch on March 3rd.
Liévano de Marques went on to say, “if we want to reduce the region's vulnerability, we must make prevention a cornerstone in our development programs. Only by guaranteeing that our countries and communities stay safe can we make positive development progress.”