Appropriate rehabilitation strategy for a traditional irrigation supply system: a case from the Babai area in Nepal

摘要

This paper studies primary canals of three traditional irrigation systems in the southern plains ofnNepal. It offers a scientific interpretation of the indigenous technology applied to the systems,nwhich facilitates to use the same channel network for irrigation, drainage and flood management.nThe flood management technology of the farmers by diverting as much discharge as possible tonthe field channels results in the reduction of discharge towards the downstream part of the mainnchannel. It is depicted in the simulation study that uses the river analysis program HEC-RAS 4.0.nA cascade of weirs is found to be the most cost effective and user-friendly option to upgradenthese systems preserving the existing irrigation, drainage as well as flood management functions.nThis study suggests that the conventional irrigation design principles should be applied veryncautiously with full knowledge of the existing socio-institutional setting, hydro-ecological regimenand indigenous technology for upgrading any traditional irrigation system successfully.nThe indigenous flood management technology strengthens the emerging concept that the floodsnin the Ganges plain are to be managed, not controlled.