An integrated water resource management tool for the Himalayan region

The Himalayan region of Nepal and northern India experiences hydrological extremes from monsoonal floods during Julye September to periods of very low flows during the dry season (DecembereFebruary). While flooding causes significant damage to local populations and infrastructure, the lack of water during the dry season impacts people’s agriculturally based livelihoods. Furthermore, competition for water for irrigation, domestic supply, industrial uses and hydropower is at a maximum during the dry season. Successful management of water resources is dependant on an ability to balance the natural availability of water with the pressures exerted by water-users. A software system has been developed to assist water resource practitioners in the region to meet these goals. The software incorporates regression-based hydrological models that enable long-term average monthly recession flows to be estimated in ungauged catchments. Recessions are the periods of successively decreasing flows that occur during the dry season. Users are able to compare predicted flows with observed flows recorded at gauging stations. The impact of existing and future water use scenarios on dry season flows can be simulated by characterisation of seasonal water use at points within the catchment. The user-friendly interface is Geographical Information System based, providing the ability to add contextual spatial data to enhance the application of the conceptual model. Standard display and output formats provide a consistent set of reporting tools. This paper describes the components of the system and presents a case study implementation in the West Rapti catchment (Nepal).