More than 30,000 families have been identified as at risk of landslides following Cyclone Ditwah, and ground previously assessed as safe can no longer be treated as safe, the National Building Research Organisation has warned, the Daily Mirror reported.
NBRO Senior Scientist Dr. Wasantha Senadheera said preliminary signs of landslides have already appeared in several cyclone-affected areas amid continued heavy rainfall.
His central warning concerns ground that has moved without failing. Where soil and rock have already shifted but no landslide has yet occurred, he said, renewed rainfall can trigger one — meaning the absence of a visible slip is not evidence that a slope is stable.
“After the cyclone, even places we considered safe have become unsafe,” Dr. Senadheera said, urging residents of landslide-prone areas to move immediately when heavy rain sets in rather than waiting for an official evacuation.
How the 30,000 breaks down
The figure is the sum of two separate counts, which the reporting does not present as a single new assessment:
| Cohort | Families |
|---|---|
| Newly identified since Cyclone Ditwah | 16,793 |
| Identified as high-risk over the past 15 years | ~15,000 |
| Of those, currently being resettled | ~5,000 |
Dr. Senadheera said the total could rise further, as monitoring of affected areas is still under way.
Against the figure reported two weeks ago
This is the second time in a month the NBRO has put a number near 30,000 on landslide exposure, and the two are not the same measurement.
On 1 September the organisation said nearly 30,000 houses stood in high-risk zones in a condition requiring relocation, of which 16,746 were Ditwah-affected. That was a count of housing stock judged unsafe. Wednesday’s figure counts families at risk and arrives at a similar total by adding a post-cyclone cohort of 16,793 to a legacy cohort of about 15,000.
The Ditwah sub-total has risen by 47 — from 16,746 to 16,793 — in the fifteen days between the two statements, consistent with Dr. Senadheera’s point that assessments remain open. But the two totals are built differently, and neither account acknowledges the other. Whether roughly 30,000 is a stable ceiling or a running figure is not clear from either.
Two further warnings
Dr. Senadheera cautioned the public against approaching landslide-prone areas to watch or film slips, saying the practice puts lives at risk. He also urged people to follow warnings issued by government institutions rather than acting on unverified information circulating on social media.
Not reported
The Daily Mirror does not name the districts or divisions where the 16,793 families were identified, break the figure down geographically, or say what the resettlement programme for the 5,000 families involves, what it costs or when it concludes. It does not say how many of the newly identified families have been offered alternative land, or give a timeline for completing the outstanding assessments.
Ada Derana also filed on the NBRO’s warning but was unreachable behind a CloudFront block at the time of writing, so this account rests on a single accessible source.
