We ourselves create vulnerabilities that lead to disasters

Bagan

The monsoon winds, laden heavy with moisture from the Indian Ocean sweep towards the Himalayas.

This is caused by the suction created when the thin air over the Tibetan plateau heats up quickly and rises. As the winds desperately try to climb, they dump large amounts of precipitation onto the southern slopes of the mountains. The water hurdles down the slopes cutting away at the banks and carrying away anything that it can loosen. When it hits the plains, it fans out, inundating the flat landscape.

On the eastern edges of this weather system, heavy rains have led to massive flooding in Myanmar. The rivers have risen beyond their banks causing havoc and destruction. Of the historical sites, the archaeological remains such as those of the Ancient Pyu Cities were clearly more susceptible.

It was, however, the Mrauk-U site in Rakhine State that got inundated, but since the monuments are of stone, no major damage has been reported.

Despite being in the dry central plains of Myanmar, in the rain shadow of the Bago Yoma hill range, it was

not the flooding but direct heavy rain that affected Bagan. Temple 1752, a non-graded monument from the 13th century of which only the base existed was reconstructed in 2003 and the heavy rains caused it to collapse. The tower of Temple 1297 also partially collapsed. There were several other monuments that were partially damaged or developed cracks.

An interesting observation was that all the collapsed and cracked structures were those reconstructed over the past two decades using cement mortar. Traditionally the thick walls would have been constructed of bonded brick masonry in mud or lime mortar throughout even in the thickest parts. The entire structure would have been more flexible and would have adjusted to any movement. The reconstruction seems to have been done with a thin outer brick wall in cement mortar with the central part filled using pieces of ancient bricks stabilised in roughly half-metre layers using cement mortar. The rain would have seeped in, filled the inner cavity and then caused the structure to crack open.

In most of these cases, the problem has been cracks that allow water to seep deep into the structure. This is often the case when the structure is made up of sections from different periods and the joints have loosened over time. This was exactly our fear for the cracks caused by the recent earthquake on the hemispheric mound of Swayambhu Mahachaitya in Kathmandu. We do not have a clear understanding whether the structure has an earthen core, is built in layers like an onion or whether it is of solid brick.

Accordingly, the structure would be vulnerable to water seepage and the entire structure could dissolve and collapse, bringing down harmika and the entire tower of 13 circular rings. The cracks were sealed with acrylic paste and covered with elastic polymer membranes, but we must monitor this closely and ensure monkeys do not remove sealants. Once monsoon is over, it is imperative that this is researched in detail and a solution is found to secure the structure properly.

The earthquake did not only crack the buildings but also loosened the soil. There were many incidences where the earthquake induced landslides and avalanches. With the ground damaged by fissures, the rain can seep into the slopes causing further landslides. The threat of unstable land has led to the government ordering several dozen settlements to be relocated. This might become a disastrous exercise of creating sterile rational settlements that do not reflect any of cultural, social and even psychological requirements of displaced communities. Nature has wreaked havoc, but this is due to our own making. We ourselves create vulnerabilities that lead to disasters.

(The author is an architect and can be contacted through paharnepal@hotmail.com)