The first two filtering methods include a parameter of recession constant, and the last one has two parameters: the recession constant and the maximum baseflow index.
For the two-parameter Eckhardt method, estimating the maximum baseflow index has larger effect on baseflow separation than estimating the recession constant.
Using the recession constant estimated from the ABIT method performs noticeably better than using the default parameter, indicated by the absolute bias reduced about 20% in average.
We used an Automatic Baseflow Identification Technique (ABIT) to estimate the recession constant, which varies from 0.943 to 0.987 for the five catchments that is evidently higher than the default value of 0.925, and used the default Eckhardt and UKIH methods to estimate the maximum baseflow index, respectively.
The three recession constants, K0, K1 and K2, show very distinct patterns of IC.
Monthly baseflow recession constants were close to 1 and had little variation (ranging 0.951 0.992), indicating a well-mixed groundwater store and long residence times.
Recession constants were lower (ranging 0.727 0.955) with pronounced seasonal variations, suggesting shorter residence times and the likely presence of a variety of stores and pathways.
With respect to the impact of the interactions between parameters on the model results, it was observed that the largest effect is related to the parameters describing the size of the soil storage, the interflow and the percolation flow recession constants.
For instance, it was observed that all parameters were important at least during 1 day a daily scale, while at a yearly scale only the parameters characterizing the soil storage and the recession constants for interflow and percolation had high sensitivities.
Wall Street may overlook one-time misses, particularly when the economy slides into recession, but constant surprises from a highly leveraged company are not likely to be forgiven.
