Sri Lanka’s upcountry geography has undergone noticeable changes in several areas due to landslides triggered by Cyclone Ditwah, prompting the need to revise the country’s land-use map series, Surveyor General N.K.U. Rohana said.
He explained that the Survey Department plans to acquire high-resolution satellite images from space stations orbiting Sri Lanka to ensure an accurate re-mapping process. These images will help identify landslide-affected zones and assess the extent of damage to river basins, land areas, and agricultural regions.
“The damage is mainly to the geological landscape. Outer areas remain mostly unaffected, but some regions may require resettlement,” Rohana said. He added that the department will prioritise obtaining the detailed satellite imagery once the disaster situation stabilises and repairs to rivers, lakes, canals, bridges, roads, and highways are completed.
While basic satellite images are available free of charge, high-quality close-up images require significant funding. The department has already collected low-resolution images from disaster-hit provinces and initiated preliminary assessments.
“All mapping will be completed once conditions improve. Rapid reconstruction is ongoing, and some areas are still underwater. We must wait until the water recedes,” he noted. “We have already captured satellite images of flooded regions and begun mapping. National mapping is conducted every five years.”
The Survey Department is also seeking international assistance through diplomatic channels to obtain high-resolution satellite imagery. Countries approached include China, India, Japan, the United States, and Russia.
China has already provided several close-up satellite images showing flood- and landslide-affected areas in Sri Lanka. However, further acquisitions may be delayed due to prevailing weather conditions and will resume once the situation clears.
The Surveyor General added that a new national-level map of Sri Lanka is now being prepared as part of this broader initiative.
