THE Jalan Masjid India tragedy on Friday in Kuala Lumpur, where an Indian national was swallowed by a sinkhole, has sent chills down the spines of the capital city's dwellers. The fear isn't unwarranted.
A large part of Kuala Lumpur is built on what is called a karst region where limestone dominates. When geology of this nature mixes with hydrology, made worse by human activity, the karst formation becomes more than a geohazard.
Limestone, as a calcium carbonate rock material, is highly soluble. Rainwater, made worse by the carbon dioxide from the atmosphere, easily dissolves the carbonate in the bedrock, leading to the gradual formation of sinkholes. Kuala Lumpur is safe, according to recently appointed Mayor Datuk Seri Maimunah Mohd Sharif, who has promised a study of the area.
But sinkholes are neither limited to the Jalan Masjid India area nor Kuala Lumpur, as experts have pointed out now and in the past. One expert, Dr Nor Shahidah Mohd Nazer, who spoke to the New Sunday Times, had called for sinkhole mapping and monitoring of urban and densely populated areas in the Klang Valley.
To this expert's call, we add our own: map and monitor all populated areas in the country where sinkholes are prone.
Sinkholes aren't the abyss that the layperson thinks they are. With a few exceptions, they are knowable and manageable. But first, they must be mapped, as a comprehensive map doesn't exist. At the moment, sinkholes seem to be largely of academic curiosity.
They must be more. Given the danger they pose to people and property, policymakers, too, must take a deep interest in them, and not just a one-off dive when tragedy, like the one on Friday, happens. It is good to have our eyes fixed on the present, because that is when the danger manifested itself. But the future, too, needs our attention because that is where all our tomorrows are.
We help begin the future by mapping all sinkhole-prone areas. One mapping method that Nor Shahidah had suggested is the use of ground-scanning devices to identify potential voids. Or by burying geophones, as they do in the Dead Sea, to predict the appearance of such holes. The Dead Sea is plagued by sinkholes — one media report puts the tally at 6,000. There, the sea is being drained of its water for human use.
Here, too, in some areas, groundwater is being starved. Having mapped the sinkholes, they must be monitored. Early warning systems and other sinkhole identification methods, too, need to be developed and deployed. Now for human activity. Years of rapid development, some of which is uncontrolled, has overburdened the surface on which our cities stand.
A case of things falling apart, with the surface not being able to hold? Climate change — again, human activity is at the centre of it — has increased the occurrence of sinkholes. Remediation and mitigation strategies may help. For the future, we have to keep a close watch on human activity, especially when it comes to our development practices. Uncontrolled development must be a no-no.
Urban and rural planning must begin to take into account not just geology, but hydrology, too.