Abstract:
This study evaluated the impact of land use/land cover (LULC) changes from 2014
to 2023 on landslide occurrences in Kegalle district, Sri Lanka. Land use/land cover
distribution patterns were assessed by comparing thematic maps from 2014 to 2023
and created using the supervised classification of Landsat 8 imagery in Google Earth
Engine. Map accuracy was verified through visual interpretation in Google Earth Pro,
referencing each specific year. Landslide data from the National Building Research
Organization (NBRO) was integrated to map spatial landslide distributions. Then, the
overlay analysis in GIS was used to identify landslide-prone areas and their
corresponding LULC types. The spatial analysis revealed a strong relationship
between LULC change and landslide occurrences. According to the results, the
forested areas and paddy lands declined by more than 3% and 4%, respectively, while
built-up and upland cultivation areas increased by over 2% and 5%, respectively
indicating urbanization and agricultural expansion. Landslide occurrences in
cultivation areas rose from 63% in 2014 to 68% in 2023. Also, landslides in built-up
areas rose from 14% to 18%. However, landslide incidents in paddy and forested
areas decreased, from 11% to 3% and 11% to 9%, respectively. These results
highlight that an increased landslide risk is associated with the expanded cultivation
and urban areas, while the reduction in incidents is within paddy and forested areas.
The results revealed that the vegetative cover may reduce the risk of landslide
occurrence in the study area. This study further emphasizes the necessity of strategic
land use planning to manage landslide risks driven by ongoing LULC changes.
