Disaster mitigation blooms on mulberry trees in Tajikistan -- Habitat for Humanity Int'l 1
Disaster mitigation blooms on mulberry trees in Tajikistan
By Katerina Bezgachina
Every year, Tajikistan, located in the Pamir range in Central Asia, experiences more than 5,000 tremors and earthquakes, the magnitude of which can go as high as 7 or 9 on the Richter scale.
In most mountainous villages, homes cannot withstand such strong vibrations. Destruction caused by natural disasters exacerbates poverty in the country, where almost half of the population lives on less than US$2 a day.
Rebar and concrete, traditionally used to reinforce homes, are financially out of reach for many Tajik families.
Habitat, in partnership with the local Institute of Seismology, came up with an inexpensive and sustainable house reinforcement technology that provides much-needed safety to low-income rural communities. It uses the mulberry tree, which grows in abundance across the country.
Trees are cut seasonally to harvest silk cocoon—the mulberry twigs have no other use and are therefore freely available. They are bound into grids and attached to walls using plaster mixed with straw and wool. This simple and affordable design makes buildings as strong as steel.
As a result, the risk of being trapped, injured or killed in the house during an earthquake is significantly reduced, and as homes are more stable, families have time to escape in case of emergencies.
So far, homes reinforced with this “mulberry tree” technology have survived two earthquakes. The first one occurred in December 2008 and measured 5.8 on the Richter scale. It sent tremors into Rasht district, where 80 homes had been reinforced. This January, a second earthquake with the epicenter in Afghanistan had a magnitude of 6 and was felt in the Kumsangir district, where 120 homes were reinforced. A post-disaster survey in both locations showed that the reinforced houses were not damaged.
Another advantage of the mulberry tree technology is that it can either be built into new construction or added to existing houses. It is 30 percent cheaper than the standard techniques used in the seismically unstable regions. If applied to existing houses, the construction costs can be reduced by five times.
Plus, there is no need to demolish and rebuild the house from the foundation up—a factor of paramount importance in Tajikistan, where very often families cannot afford new houses.
“We could not afford to rebuild the house,” said Gani, head of a family of eight who rebuilt his home with a Habitat loan. “The recommended ‘mulberry branch’ solution was just the very thing we needed to reinforce the house instead of rebuilding it. It saved both resources and time, and I now know how to build a safe house with local materials.”
Another aim of the project in Tajikistan is to ensure that construction norms and standards for rural earthquake-resistant homes are integrated into the official building code. Some 70 percent of the population lives in rural areas. Previously, there were no standards for this type of construction; thus, rural homes were more susceptible to damage when natural disasters occurred.
Low-income beneficiaries of the program live in the remote, rural Kumsangir area of Tajikistan near the Afghan border. Working with a local partner organization, Habitat for Humanity set up a revolving fund from which eligible low-income families were offered loans to pay for the house reinforcements. After these loans are repaid, funds are accessible to other members of the community.
To date, more than 200 houses have been reinforced, 160 are awaiting transformation and 400 more are being assessed for future upgrades.
Katerina Bezgachina is the communications coordinator in Habitat’s Europe/Central Asia area office.