Study of Flood Prone Regions of Rivers

Project Description

The main objective of this study was to identify the appropriate set back of rivers in Kathmandu Valley (namely Kodku (Karmanasa) Khola, Nakkhu Khola, Balkhu Khola, Karakhusi Khola, Mahadev Khola, Samakhusi Khola and Tukucha Khola) considering the flood prone regions of rivers and other related factors such as land value, existing infrastructures etc. which follow in the urbanizing area of the Kathmandu Valley and to identify problems and necessary remedies for the management of prohibited area of construction in flood prone regions.

Assignment Description

Collection and study of all the relevant data and reports including the digital maps, topographic maps, aerial photographs, Quick Bird Satellite Image, geological, hydrological and environmental geological maps, land utilization and land classification maps, soil maps etc. • Collection and review of existing hydrological / metrological data to study the rainfall pattern, distribution and discharge in the rivers and tributaries. • Assess historical flood and its impact on both local communities and natural regimes of the rivers. • Collection of data and information on the encroachment and human interventions into the natural regimes of the river system and their observed effects. • Incorporate all the new and recent water induced hazards including flood and inundated areas by verifying with local people on the ground. Delineate lateral extent of impact of floods in the river. • Crosscheck in the field the areas of settlement, infrastructure and different land uses. • Take cross sectional measurements at various locations in the river and calculate discharge in the rivers and tributaries. • Study the changes in geomorphic surfaces due to recent human activities. • Hydrogeological study of the river channel and banks. • Study the necessary remedies for the management of prohibited area of construction in flood prone regions. • Prepare water induced hazard map (1:2500) based on the findings of the desk study and the field study. • A map of watershed areas of rivers showing extent of erosion and flood prone areas and also potential landslides and debris flow prone regions. • Recommendations of appropriate set back of rivers