Hysteresis in streamflow‐water table relation provides a new classification system of rainfall‐runoff events

Abstract

Rainfall-runoff event types can be used to better understand the hydrological functioning of catchments. In this study, we propose a framework to characterize and classify runoff events relying on the hysteresis analysis of the relation between streamflow (independent variable) and depth to water table (dependent variable). We evaluated hysteresis for 112 rainfall-runoff events occurred in the period 2012-2016 in a small forested catchment in the Italian Pre-Alps. Three main groups of rainfall-runoff events were identified, each associated with specific hydro-meteorological characteristics of the events. A first group, identified by a faster response of streamflow compared to the groundwater level (which led to a clockwise hysteretic loop), was characterized by dry antecedent conditions, short rainfall events, low streamflow peaks and small runoff coefficients. A second group had characteristics similar to the first group, that is, faster response of streamflow compared to the groundwater level (clockwise hysteretic loop), but on average displayed a narrower hysteretic loop. A third group, identified by a faster response of the groundwater level compared to streamflow (which led to an anticlockwise loop), was characterized by wet antecedent conditions, long rainfall events, high streamflow peaks and large runoff coefficients. Results showed statistically significant differences among the groups, corroborated by an analysis based on environmental tracers ( 2 H and electrical conductivity). This study shows how the analysis of the hysteretic relation between streamflow and depth to water table can be used for grouping rainfall-runoff events and to better identify the catchment's hydrological response to rainfall inputs.

Nonlinear storage–discharge dynamics of forested headwater catchment: A hysteresis index approach

“…Penna et al (2011) also observed clockwise (SM lagged discharge) and anticlockwise (discharge lagged SM) loops in an Alpine headwater catchment during dry and wet conditions, respectively. An analogous hysteresis loop inversion was also reported by Gelmini et al (2022) for discharge and water table dynamics in Ressi headwater catchment located at the foothills of the Central‐Eastern Alps. Similarly, studies conducted by Weill et al (2013) reported the dependence of discharge–storage hysteresis behaviour on mean saturation of the catchment and further development of the linear relationship between storage and discharge during higher degrees of saturation.…”

“…The HI was well tested using various combinations of the field data collected from the Ressi, Alta Val de La Mare, and Bridge Creek catchments of Italy, in which the independent variable was discharge, and the dependent variables were SM, depth to the water table, electrical conductivity, and $$$ {\delta}^2H $$$. Gelmini et al (2022) also used Zuecco's HI to study streamflow and groundwater table relationships to classify rainfall‐runoff events in the Italian Pre‐Alps.…”

The Timing of Global Floods and its Association with Climate and Topography

“…Whether the regional mechanism explaining the link between topography, water table, and flooding is dominated by saturation or infiltration processes (Blöschl, 2022) is an attractive question to follow this analysis. For instance, it could be addressed by looking into the shape of the evolving relationship between rain-fall, runoff, water table levels and flooded extent (e.g., Gelmini et al, 2022;Reager et al, 2014;Zuecco et al, 2016) at a regional level.…”

Nitrate-nitrogen dynamics in response to forestry harvesting and climate variability: Four years of UV nitrate sensor data in a shallow, gravel aquifer

“…Where rainfall recharge is the driver of changes in groundwater levels and nitrate-nitrogen concentrations, 120 hysteresis analysis can be used to identify the lag between these two variables following a recharge event. While several hysteresis studies have considered the effect of near stream groundwater on stream-derived hysteresis curves, continuous high-frequency groundwater measurements have not been widely utilised (Aubert et al, 2013;Jacobs et al, 2018;Knapp et al, 2020;Winter et al, 2021;Gelmini et al, 2022).…”

“…In concentration-discharge studies the input of near stream groundwater is recognised (Knapp et al, 2020;Winter et al, 2021;Gelmini et al, 2022) but the timing and variation of groundwater solute discharges is source of nitrate-nitrogen, the timing of greatest surface water-groundwater connection (highest groundwater level) compared to highest nitrate-nitrogen concentration could be investigated. This study highlights that the nitrate-nitrogen concentration in groundwater can be just as varied as stream concentrations at the event scale 445 and is a valuable addition in understanding riverine hysteresis processes.…”