Sri Lanka’s upcountry geography altered by cyclone Ditwah

By Indika Sri Aravinda

Colombo, Dec 12 (Daily Mirror) - Sri Lanka’s upcountry geography has changed in certain areas due to landslides triggered by cyclone Ditwah, warranting revision of the land-use map series in view of several areas severely, Surveyor General N.K.U. Rohana said.

He said the Survey Department plans to obtain high-resolution satellite images from space stations orbiting Sri Lanka to support an accurate re-mapping process. The new images will help identify landslide-hit zones and assess damage to river basins, land, and agricultural areas.

“The damage is mainly to the geological landscape. Outer areas remain mostly unaffected, but some regions may need resettlement,” Rohana said. He added that obtaining detailed satellite images will become a priority once the ongoing disaster situation stabilizes and repairs to rivers, lakes, canals, bridges, roads, and highways are completed.

Although basic satellite images are available for free, high-quality close-up images require substantial funding. The department has already collected several low-resolution images from disaster-affected provinces and begun preliminary studies.

“All mapping will be done once the situation settles. Rapid reconstruction is underway, and some areas are still underwater. We must wait until water recedes,” he said. “We have already taken satellite images of flooded regions and started mapping. National mapping is carried out every five years.”

The Survey Department is also seeking international assistance through diplomatic channels to obtain high-resolution satellite imagery. Countries including China, India, Japan, the United States, and Russia have been approached.

China has already provided several close-up images showing flooded and landslide-affected areas in Sri Lanka. However, further acquisitions are expected to be delayed due to prevailing weather and will continue once conditions improve.

A new national-level map of Sri Lanka is being prepared as part of this initiative, the Surveyor General added.