THESIS ABSTRACT

Abstract

Landslide is significant natural disaster occurring time and again in Nepal especially during the monsoon season. The destruction caused by landslide don’t stop to infrastructure damage, it extends up to loss of life and property. Bagmati province being one of the most dominant provinces in the infrastructural development yet it faces natural disaster like landslide due its wide range topography, extreme weather events and human interventions. Being hub of electricity production and load center, this province is linked with very high importance in electricity and power sector of Nepal. Landslide hazards in this province is also associated with high voltage transmission lines linking to and from this province creating serious issues and disruption time and again. Landslide susceptibility map and its connection with the reliability of high voltage transmission line is way far critical. In this study, landslide triggering factors including slope, aspect, geology, rainfall, land use landcover, plan curvature, profile curvature, distance to road, distance to fault, distance to river, Normalized difference vegetation index (NDVI), Topographic Wetness Index (TWI) were considered. Geographic Information System (GIS) was used as a tool to create landslide susceptibility map of this province where Analytic Hierarchy Process (AHP) was used. Weightage of each parameter and pairwise classification of each factor of every parameter was done through key expert questionnaire survey. Consistency checks for the pairwise comparison of each factor was placed inside the tolerable limit of ten percentage. The thematic layers so obtained was reclassified and weightage overlay was done to produce landslide susceptibility map of the study area. Validation is crucial for the accuracy of landslide models. The validation of the map was done using the landslide inventory and Area Under Curve (AOC) and Receiver operating Characteristics (ROC) curve with validity of 0.896 ratio. The final map resulted high susceptibility zone at 14.6%%, medium susceptible zones as 78.4% and least susceptible zone at 7%. The thirteen under construction transmission lines of the province was plotted in the same environment to overlay susceptibility zones with transmission lines. The result showed that most of the transmission lines are in medium susceptibility zones covering 60.61%, followed by high susceptible 11.6% and 27.79% as least susceptible zone. The landslide susceptible map is expected to increase deep sights during the planning phase of transmission lines avoiding and optimizing the transmission line routes. This would help to consider attention in major landslide triggering factors and in planning the mitigation efficiently and ahead of any mishaps protecting the infrastructure and its resilience.

Keywords

Landslide susceptibility mapping, Bagmati Province, Geographic Information System (GIS), Analytic Hierarchy Process (AHP), High voltage transmission lines, Receiver operating Characteristics (ROC)