OIDA International Journal of Sustainable Development
Open-access peer-reviewed journal
https://doi.org/10.64211/oidaijsd190506
Landslide Vulnerability and Risk Assessment of Matara District Using the Geospatial Technologies
Posoni Himara Hewa Kokawalage 1*, H.M.Badra Herath 2
Department of Geography, Faculty of Humanities and Social Sciences,
University of Sri Jayewardenapura, Sri Lanka
* Corresponding author: posonihk@gmail.com
Volume 19, Issue 05, Pg. 77-90, 2026.
Abstract: Landslides can be identified as one of the major natural hazards to Sri Lanka. Nearly 20,000 km2 encompassing ten districts are prone to landslides in Sri Lanka. According to the data from Disaster Management Centre, the highest number of landslides were occurred in Matara District in 2017. So, identifying landslide susceptibility zones are important to take prevention actions of landslides as the first step. GIS- multicriterial evaluation on slope, elevation, topographic wetness, year 2023 vegetation cover and 2013 – 2023 annual average rainfall of physical and environmental landslide susceptible factors using GIS based Weighted Overlay Process, the study has identified Kotapola and Pasgoda Divisional Secretariat Divisions are having more than 5 km2 areas of landslide susceptibility than other fourteen Divisional Secretariat Divisions of Matara District. Assessing the vulnerability of the landslide is important to mitigate the impact and minimize the damage of the event. Therefore, this research study has identified socio-economic vulnerable zones using built-up areas, road network and population data. Then 13 Grama Niladhari Divisions were from 36 Divisional Secretariat Divisions of Kotapola Divisional Secretariat Division and 12 Grama Niladhari Divisions were from 43 Grama Niladhari Divisions of Pasgoda Divisional Secretariat Division were identified as high landslide vulnerable zones. More than 20 Grama Niladhari Divisions are having risk of landslide and it is occurring since those areas belong to at least one of the socio-economic vulnerability analysis factors. This geospatial approach enables effective sustainable natural resource management via the establishment of environmentally susceptible areas with the landslide susceptibility and risk mapping. Being the non-structural and structural mitigation methods, the geospatial analysis in this study is a core foundation for the implementation of structural mitigation. Determining landslide susceptibility zones as well as socio-economic vulnerability zones, this method enables the first step of the disaster management cycle such that more targeted and improved interventions could be made to prevent landslide hazards.
Keywords: Geo Spatial Approach, Landslide, Risk Assessment, Susceptibility, Weighted Overlay Process.
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