Disaster Preparedness: It's Not the Earthquake that Kills Us

The earthquake that shook Yogyakarta on Saturday morning, May 26, 2006, seemingly did not affect Nurul Khusna's house in Jejeran Hamlet, Wonokromo Village, Pleret District, Bantul Regency. The house stood tall without any cracks. All the glassware and furniture was still in their original places. This was despite the fact that almost all the houses in the surrounding area had collapsed.

"The earthquake felt strong, but I thought it was just a regular earthquake. All my kids slept through it and none awoke. It was only after I went outside that I was shocked that all the other houses had collapsed, including my mother's house right next to ours," said Nurul, who teaches at the Madrasah Tsanawiyah 1 Islamic junior high school in Wonokromo.

Despite the earthquake, the epicenter of which lay about 15 kilometers east of the Opak River, being only of a magnitude 6.4 in the moment magnitude scale (Mw), it was highly destructive. Apart from the epicenter being in a shallow land area, the soil in Bantul has a thick alluvial sedimentation layer that amplifies the shocks.

Thousands of buildings collapsed. More than 6,000 died and 40,000 more were wounded in the strongest earthquake in Yogyakarta's modern history. Jejeran Hamlet was among the worst-hit regions. Of the 156 houses in the hamlet, only three withstood the quake. Twenty-two residents died from being crushed under the rubble and dozens of others were injured. "At first, my husband and I thought it was just a coincidence that our house was left unscathed," Nurul said.

However, that miracle was in fact the work of construction foreman Ismawan, who lives across the road from Nurul. Without being asked, Ismawan applied the barrataga earthquake-resistant construction technique when he got the order to build Nurul's home back in 2004. The two other houses that survived the earthquake in Jejeran had also been built by Ismawan using this technique.

Barrataga, an acronym for "bangunan rumah rakyat tahan gempa" (earthquake-resistant people's housing), is a local engineering technique. Ismawan learned the barrataga technique from construction expert Sarwidi, who serves as a professor of civil engineering at the Indonesian Islamic University in Yogyakarta. Since 2004, Sarwidi has been actively training construction workers and foremen in earthquake-resistant construction techniques.

"My husband (Ghoizon) and I only knew that my house was earthquake-resistant after a group led by Pak Sarwidi came to my house in the afternoon after the earthquake to see if there was any damage to my house," Nurul said, "When we built the house, we gave free reign to Pak Ismawan to do what he wanted to do with the available budget."

According to Sarwidi, the barrataga principle that he invented involved pouring a 20- to 30-centimeter layer of sand under the foundation. "The function is to withstand the shakes of an earthquake," he said.

Reinforced concrete must also be used in every part of the construction, including foundation blocks, columns, roof blocks and lintels. These blocks are connected to each other and are anchored with steel reinforcement bars to the walls. The walls need to be constructed with good-quality bricks. Light-but-strong materials are suggested for the roofing so that it can withstand shocks.

Houses constructed with the barrataga technique, according to Sarwidi, can withstand shocks of VIII-IX on the MMI scale, equivalent to earthquakes of magnitude 8 as measured by the Richter scale. "Currently, we are still conducting more research to simplify and make cheaper the implementation of the barrataga technique," he said.

After the earthquake, many locals asked Ismawan to build their homes using the Barrataga technique. They realized that it would not be the earthquake that killed them. Instead, it would be the houses constructed not using earthquake-resistant methods.

According to Sarwidi, apart from educating construction workers, changing people's mindsets to be more aware of the importance of earthquake-resistant buildings is also important.

Preserving the memory

Ten years after the Yogyakarta earthquake, the signs of destruction are almost gone from Bantul. Life has completely gone back to normal and the destroyed villages are thriving and even more densely populated nowadays.

This is the unique resilience of Indonesians in the face of calamity, just like in Aceh, Pangandaran and other disaster-stricken regions. However, this resilience and optimism is often fostered at the expense of the awareness to reduce the risks of possible disasters in the future.

Some five kilometers away from Jejeran Village, in Potrobayan Hamlet, Srihardono Village, Pundong, a monument to remember the 2006 Yogyakarta earthquake tragedy stood by the Opak River. The monument was publicly revealed in the earthquake's 10th anniversary commemoration ceremony on May 26, 2016.

Four Panjang Rejo junior high school students visited the monument on Friday (10/6/2016) morning. When asked about her reason to visit the monument, Atikah (13), said: "I wish to know the center of the earthquake that destroyed my home."

What would she do with the knowledge? "Well, so that we can always remember and prepare ourselves if the earthquake strikes again. At school, we are trained on what to do when earthquakes strike," said Dewi (13), firmly.

The answer gives us all a new hope...

Source Kompas, Tuesday, June 14, 2016