Conceptual Framework of Effective Flood Forecasting and Early Warning System in Nepal: A Case Study of Koshi River Basin.

This study presents a conceptual framework of effective flood forecasting and early warning system in Nepal. The study is focused on Koshi River basin. In the proposed framework, HEC-HMS model can be applied for real flood forecasting purpose. The telemetry system and warning system should be developed for the operational forecasting system. Flood forecasting and warning center should be established in coordination of concerned authorities and institutions including DHM. For an effective flood forecasting and early warning system in Koshi basin, existing hydrological and rain gauge station network should be augmented. In hydrological station network, an additional station at Dudhkoshi upstream of the confluence of Dudhkoshi and Sunkoshi is proposed. Hampacuwar station of Sunkoshi should be operated to know the contribution of whole Sunkoshi and also to get the idea of contribution of tributaries downstream of the confluence of Dudhkoshi. Simle station of Arun near the confluence of Sunkoshi should be operated to get an idea of the contribution of whole Arun basin. Each additional rain-gauge station in the upper part of Tamakoshi, upper part of Dudhkoshi, upper part of Arun and upper part of Tamor is proposed. This method may be effective in the flood risk management in the Koshi alluvial fan and can be introduced in Himalyan Rivers in Nepal.