Philip Young: Choose construction sites with care

The ruins of Xuankou Middle School, where 55 people died in the 2008 quake, remain as a memorial and form the centrepiece of the Wenchuan Earthquake Relic Park. Photo / Jamie Morton

Opinion

May 12, 2013, marked the fifth anniversary of the Wenchuan earthquake in the Sichuan Province of China.

This earthquake measured magnitude 8.0 with the epicentre at a depth of only 14km. The fault zone measured more than 240km long and nearly 40km wide, and the rupture occurred in a mere 80 seconds.

This was a disaster of immense scale and impact, felt not only through the number of casualties but also the sheer number of people affected.

The official death toll of the 2008 event was nearly 70,000 people, another 18,000 went missing and more than 370,000 were injured, with damage spread over thousands of square kilometres.

I was a co-leader of the reconnaissance team sent by the New Zealand Society of Earthquake Engineering to the area, to observe the effects and to report on lessons we could learn from this massive earthquake.

One feature of this earthquake was the unprecedented scale of the geo-hazards that followed, from landslides, quake lakes and debris flows.

The earthquake triggered over 15,000 landslides, directly causing more than 20,000 of the fatalities, and in many cases blocked roads, damaged bridges and buried buildings and townships.

The key lesson is the need for careful selection of development sites for geo-hazards and potential threats to life and properties.

This is a lesson for the Chinese, too - avoiding building on high-risk sites has been the key consideration in the reconstruction planning.

Many casualties were caused by collapsed buildings that were poorly engineered, constructed of materials such as unreinforced masonry or inadequately detailed reinforced concrete.

The key lesson for New Zealand: there is a need to urgently deal with our stock of earthquake-prone buildings.

The response from the Chinese Government for such a massive event was considered well-resourced and effective, with recovery and reconstruction plans in place just months after the earthquake.

Visiting the area one year after the earthquake, we learnt infrastructure and school projects were being built with a key requirement - resilience.

In New Zealand, we need to reaffirm our emergency preparedness and be ready with effective response plans both at government and community levels.

The Sichuan Earthquake

What: Magnitude 8.0 earthquake
Date: May 12, 2008
Affected areas: Sichuan Province, specifically Wenchuan County.
Fatalities: 69,195 (18,392 missing)
Cost: $206 billion.

The series

As a fellow of the United States-based East-West Center, Herald science reporter Jamie Morton travelled to China, New York and Japan to investigate how those countries had responded to their recent natural disasters.

The series aims to highlight how decision-makers, scientists and victims around the world coped with disasters, and why these disasters remain directly relevant to every New Zealander.

The series concludes with a look at our own risk profile - and what we have learned since the first devastating quake hit Canterbury.
Today: China's fight against earthquakes
Tomorrow: New York after Sandy
Wednesday: Japan's tragic lesson
Thursday: Tohoku: life in the aftermath
Friday: New Zealand: living with disaster.