Mapping of Geological Sensitive Areas along the Budhi Khola Watershed, Sunsari/Morang Districts, Eastern Nepal Himalaya

The geological sensitivity mapping was carried out in the Budhi Khola watershed, eastern Nepal covering about 140 Km2 areas from its origin to flat land of the Bhabar region. The study was aimed to assess the geological sensitive areas which are vulnerable to human life, properties, and environment. The objectives of the study were set to find the geo-hazards within the watershed area, to pick out their root causes and social impacts. To determine the geological sensitivity zones, an extensive field investigation was carried out to collect the relevant data. Geological sensitivity map was prepared in 1:25,000 scale including all the adverse geological processes occurring within the watershed. The major geo-hazard zones in this watershed are due to activity of active fault, extreme floods with debris flows, active landslides, active riverbank cuttings, haphazard mining of construction materials from the recent flood plains and over-pumping of groundwater. These adverse activities have direct impacts on human communities and environment. The map can be used to predict the possibilities of geo-disasters. It can also be used for land use planning and infrastructural developments in the region. Finally, mitigation measures are recommended to protect the watershed from geological hazards and to build disaster resilient community.