Almost everybody in the developed world suggests that ‘Drop Cover Hold’ (or Duck, Cover and Hold) is the best policy during an earthquake. A lot of NGOs and INGOs had suggested the techniques and taught it to the Nepali school children. The April 25 earthquake showed that the ‘Drop Cover Hold’ notion was wrong in Nepali contest, in a very disastrous way. A lot of corpses positioned in ‘Drop Cover Hold’ were found in the rubble after the earthquake. Many believe, a lot of those who died might have survived if they had run out instead of taking cover in the crumbling buildings.
More corpses were found in the “Drop cover hold” position. That is because u don’t study infrastructure and focus on finishing INGO money.
— Swapnil (@swwwap) May 30, 2015
What is Drop, Cover and Hold ?
In the event of an earthquake, people are instructed to ‘Drop’ down so that they don’t fall and take ‘Cover’ under something strong. People are asked to get under sturdy bed, desk or table to avoid falling objects. They are instructed to ‘Hold’ on something to keep themselves steady until the earthquake shaking stops. The person can get out to the open space after the shaking stops.
This method holds good if the building is constructed to deal with earthquake. Most of the structures in earthquake prone zones in the world are made earthquake resistant and they can hold on for a while, until the people escape after earthquake before falling down. That is why the method is widely publicized. Following are some of the official documents of different countries.
Screenshot from – http://www.eqc.govt.nz/be-prepared/earthquake
University of Southern California has a website dedicated to the notion – http://www.dropcoverholdon.org/
As Kathmandu falls in a high seismic zone, school children and adults were trained on how to deal at the time of earthquake by various NGOs and INGOs. As the professionals were trained in developed countries, they brought ‘Drop, Cover and Hold’ technique to the Nepali people. The following screenshot is a video of such training by Nepal Risk Reduction Consortium, a UN funded project.
Why Drop, Cover, and Hold failed ?
Nobody can deny that ‘Drop Cover Hold’ is the best practice. But, it is good only when the building is designed to resist an earthquake.
When the building is made of unreinforced masonry, or if the columns are weak the whole building might collapse and crush the person inside to death. That had happened to many buildings in Nepal during the April 25 earthquake. For example, the 7-storied school building in the following video has collapsed as if it was a controlled demolition. Thankfully it was closed on holiday at the time of collapse saving more than 500 students.
The DCH awareness program was held in about 2,000 schools in the 11 districts in Nepal by NGOs like NSET and Red Cross Society. In addition to the school program, radio, television and print media had also conveyed the DCH message to people.
Examples (from Nepal weekly):
- Kalpana Gajurel of Laharepauwa, Rasuwa was preparing for Plus-two exam in front of her house. When she felt the earthquake, she went inside her home and went under the bed. The house collapsed and she died inside.
- In Kahule, Nuwakot five kids were playing in the open place at the time of earthquake. All five of them went inside their house to do Drop, Cover and Hold and lost their lives.
- The wife and daughter of Bilprasad Shrestha of Arughat, Gorkha were on the top floor of their house at the time of earthquake. The daughter went to the floor below to get cover. The house collapsed, there was nobody to rescue the poor girl.
These children were taught to get cover under bed, desk and not to run. Those who didn’t care to follow the instruction ran out of houses and survived.
In case of the house built on soil mortar, having heavy floors and roof, and not-made-to-withstand earthquake, DCH is the worst suggestion anybody can give. No table or beds can withstand the heavy loads of floor, roof or the masonry wall of such buildings. That was the case of the most of the villages and some parts of the cities in Nepal.
Why was Drop, Cover, and Hold recommended ?
There are certain conditions for the DCH to work. Some of the conditions include:
- When it is safer inside than outside
- When the roof or floors of a house are not too heavy.
- When running to safety is not an easy option
- When the desk or bed are strong enough to support the falling objects
There is an example on the April 25 earthquake when DCH would have worked: A woman was killed outside the Horizon Apartment complex by a falling object. If she were to take cover inside, she would probably be saved as the apartment didn’t fall down.
Taking DCH into consideration, an Israeli designer has designed a school desk that can take a load of up to 10 tons.
What next ?
Although it has failed miserably in Nepal, DCH is still the best practice during earthquake. If economy could permit, all the non-earthquake-resisting buildings should be demolished and replaced by light weight earthquake resisting building. But, that might not be practical in current situation. My suggestion:
- Buildings be categorized as earthquake resistant building and non-earthquake resistant building. People should be discouraged to live in non-earthquake resistant building. An alternative, “Run to Safety” evacuation plan should be taught to the residents.
- The locations of all the unattached materials in a house like TV, computer, utensils, sharp objects should be secured and stowed in right place.
- Every residential building, public buildings, schools and other structures should have a proper evacuation plan. Evacuation drills should also be conducted regularly.
- All buildings should be retrofitted to make earthquake resistant.
House built on soil mortar and the houses with heavy floors and roof should be retrofitted to make them earthquake resistant. The earthquake resistant dwelling units should contain light weight building materials and shouldn’t crumble down during an earthquake.
We need to build better structures and practice DCH during future earthquakes.