Blending neighbor-based and climate-based information to obtain robust low-flow estimates from short time series

This paper combines two approaches aimed at obtaining robust estimates of low-flow characteristics from short records and presents results for a low-flow index, the minimum monthly discharge with a 5 year return period (noted Q(MNA5)). The two adjustment methods are first compared on a large set of catchments in France. The first method bases its adjustment on long-term climatic information and its sensitivity to the length of the short series is explored. The second method bases its adjustment on long-term streamflow information from a neighboring index catchment; its sensitivity to the proximity of the index catchment is analyzed. Finally, the climate-based and neighbor-based methods are combined, which confers specific robustness to the resulting flow adjustment approach.