ESTIMATING FLOOD MAGNITUDE IN UNGAUGED MOUNTAIN CHANNELS, NEPAL

Indirect estimates of flood magnitude may be useful for resource management along ungauged stream channels. Such estimates may be developed either from statistical analyses of regional hydrologic data or from physical measurements of channel characteristics. Channel characteristics that record flood magnitude include erosional and depositional features indicative of peak stage. These peak stage estimates may be converted into discharge estimates using step-backwater hydraulic procedures if channel geometry at the time of the flood can be determined. Discharge estimates from scour lines along five study reaches in ungauged mountain channels in Nepal are presented as examples of this methodology.