Effect of Landslide in Southern Part of the Up Country Area: With Special Reference on Haldumbulla and Imbulpe Divisional Secretariat Divisions

Abstract

Landslides are normally associated with intense monsoon and inter-monsoon rains .Nearly 13,000 km2 )20 %area of the country (in Ten administrative districts Badulla, NuwaraEliya, Matale, Kandy, Kegale, Rathnapura, Kalutara, Galle, Matara and Hambanthota are considered on the landslide prone. Haldumbulla and Imbulpe divisional secretariat divisions have been selected as the study area of the study. It locates at Ratnapura and Badulla districts The main research objective is to identify landslide risk areas of the selected area .The research carried out with the weights and ratings decided on consided spatial analysis and 3D analysis with creating model by ArcMap 10.3 software .Generally Slope Angle, drainage pattern, rainfall, land use, soil type, Bedrock Geology, joint patterns are effected factors for landslide .This research was considering the complex nature of landslide potential decided based on the variations of slope angle, drainage pattern, rainfall, land use factors .Landslide hazard zonation maps are useful in planning human settlements, infrastructure and other development activities and investments in mitigation .It may be very important to investigate Increase of landslides, Property damage and Loss of life etc .Hazard zonation maps of the area to identify the degree of the risk of the area of the site from natural hazards .Finally identified risk areas from this study using above main criteria .Recommended for slopes within 8- %60% construction of houses suit to the slope angle and minimum damage to the slope .Slope should be protected against erosion and degradation -natural vegetation cover -economical and as landscape function .The risk maps could be utilized for human activities, policy makers, identifying economical mitigatory measures and issuing landslide early warning .