Base-flow separation in the source region of the Yellow River

Base-flow separation has long been an important research topic in hydrology. In the Yellow River Basin in China, base flow is of special concern in the headwater catchments because of its importance for integrated water resources management in the basin as a whole. To quantify base flow in the headwater catchments of the Yellow River Basin for 1956-2000, the two-parameter Kalinin method has been proposed with improved implementation procedures and parametrization techniques. Results show that base flow contributes a larger proportion to streamflow in the headwater catchments than that of surface flow, but with a rather low variation. The results are consistent with that of the other two digital filter methods. Sensitivity analysis of parameter performance in the Kalinin method shows, in detail, that the hydrograph of separated base flow is sensitive to a recession constant, and the other parameter (beta) is highly related to the base-flow index and the ratio of base flow against surface flow (delta).