Utilization of inferred landslide hazard information as a web based decision making tool for landslide disaster risk reduction and early warning

Abstract

The highlands of Sri Lanka are affected by rain induced landslides and associated land degradation. Over the past 3 decades, the Government of Sri Lanka with the technical cooperation of international institutions such as UNDP, ADPC, NGI and JICA has implemented several programmes for landslide disaster risk reduction in the country. As a result, landslide hazard zonation maps are prepared for all landslide prone districts. The landslide susceptibility information derived from landslide hazard maps serves as the base for risk assessment, issuance of early warning, landslide education, mitigation and issuance of landslide clearance certificates. Many national and private sector organizations utilize the landslide hazard maps for selecting suitable sites for future developments. The major problem faced by the users of hazard maps in printed format is the mismatching which often takes place in relating the zonal boundaries identified in the map with actual ground conditions. Even though this problem can be eliminated by utilizing the maps in digital format, many users in rural areas lack the access to the required GIS software. In the usage of digital format also, misinterpretation of hazard potential occur in borderline cases. The author has attempted to integrate the landslide hazard information with the parcel based land information for developing a web based tool which identifies landslide potential at land parcel level. As the land parcels are demarcated on the ground, this tool can be effectively utilized for planning of development activities and implementing landslide disaster risk reduction activities. A part of the Uva Paranagama Administrative Division of the Badulla district was selected as the study area used for developing this web based tool which can easily be replicated to other areas with the availability of land information. As the internet can be conveniently accessed, a majority of map users will be benefitted by the developed landslide information tool.