Recession analysis 42 years later – work yet to be done

Abstract

Abstract. Recession analysis is a classical method employed in hydrology to assess watersheds’ hydrological properties by means of the receding limb of a hydrograph, frequently expressed as the rate of change in discharge (dQ/dt) against discharge (Q). This relationship is often assumed to take the form of a power law −dQ/dt = aQb where a and b are recession parameters. Recent studies have highlighted major differences in the estimation of the recession parameters depending on the method, casting doubt on our ability to properly evaluate and compare hydrological properties across watersheds based on recession analysis. This study shows that estimation based on collective recessions as an average watershed response is strongly affected by the distributions event inter-arrival time, magnitudes, and antecedent conditions, implying that the resulting recession parameters do not represent watershed properties as much as they represent the climate. The clear conclusion is that proper evaluation of watershed properties using recession analysis requires considering individual recession events.

An Empirical Reevaluation of Streamflow Recession Analysis at the Continental Scale

“…The result that observed streamflow recession compatible with Boussineq‐type behavior is most likely in dry, flat, impermeable catchments may be seem counterintuitive. However, this is consistent with the known effects of watershed memory (Jachens et al, ) and catchment heterogeneity (Harman et al, ) in increasing the b values of observed recession. The implications of these results for mechanistic alternatives to hillslope hydraulics as the foundation of Boussinesq‐type behavior are discussed in detail below.…”

“…Water Resources Research effects of watershed memory (Jachens et al, 2019) and catchment heterogeneity (Harman et al, 2009) in increasing the b values of observed recession. The implications of these results for mechanistic alternatives to hillslope hydraulics as the foundation of Boussinesq-type behavior are discussed in detail below.…”

Spatial and Temporal Patterns in Baseflow Recession in the Continental United States

“…However, it is becoming increasingly common to interpret the data point-cloud as a mathematical artifact (Jachens et al, 2019;Sánchez-Murillo et al, 2015) and to acknowledge that point-cloud based regression methods systematically underestimate the nonlinearity of observed recession events (Santos et al, 2019;Tashie et al, 2020). Instead, many researchers have begun to assess watersheds according to the typical values of recession parameters calculated using individual recession events (e.g., Dralle et al, 2017;Shaw & Riha, 2012).…”

Review

“…2019;Santos et al, 2019). Jachens et al (2019) in particular demonstrate the fallacy that the apparent pattern of the aggregated data in dQ/dt vs Q space (e.g., envelopes of b = 3 to 1 or other values of b estimated directly from aggregate) represent aquifer properties but rather arise from properties of the climate (i.e., magnitude and interarrival times of recharge events). Even to the extent the patterns do reflect aquifer properties, the authors do not show that the single Boussinesq aquifer (much less the simplifying assumptions required to achieve the analytical solutions) is a "good enough" representation of complex watershed made of multiple hillslopes and landscape scale heterogeneity in hydraulic properties to allow them to estimate aquifer properties using the proposed technique.…”

“…How do the authors reconcile that fact that the b = 1 here is an artifact of the linearization of the sloping Boussinesq equation and does not occur if the equation is not linearized (e.g., Bogaart et al 2013)?162-169: The authors may want to seeRoques et al (2019), who present an improve-…”