Comparative Study of Flood Impacts and Damages by Major Trans-Boundary Rivers in Nepal using MCDM

Abstract

This paper presents results of a comparative study on flood impacts and damages by major trans-boundary rivers in Nepal. The study covers four major rivers- Koshi, Kamala, Narayani and West Rapti. The source of flooding in the selected rivers is mostly continuous (monsoon) rainfall and cloudbursts. The main causes of flooding in the riverbank areas of the selected rivers were hydrological, geomorphological, structural and institutional. The flood impact, loss and damages were focused on 13 parameters including human loss, injuries, property loss, socio-economic impacts and damages of physical infrastructures. The ranking of rivers on the basis of loss and damages were assessed using simple additive weighting (SAW) method of MCDM model. Shannon entropy method was applied for the assignment of criteria weights. Among those rivers, impact of Koshi floods in the past in terms of loss and damages of human lives and properties was observed in the top. The overall assessment ranks the rivers from highest degree of impact, loss and damages to the lowest as Koshi > Kamala > Narayani > West Rapti.