Hysteresis in streamflow‐water table relation provides a new classification system of rainfall‐runoff events. Issue 9 (20th September 2022)

• Record Type: Journal Article
• Authors: Gelmini, Ylenia; Zuecco, Giulia; Zaramella, Mattia; Penna, Daniele; Borga, Marco
• Is Part Of: Hydrological processes. Volume 36:Issue 9(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-09-20
• Subjects: electrical conductivity -- experimental catchment -- groundwater level -- hysteresis -- rainfall‐runoff event -- stable isotopes; Hydrology -- Periodicals; Hydrology -- Research -- Periodicals; Hydrologic models -- Periodicals; Hydrological forecasting -- Periodicals; 631.432
• DOI: 10.1002/hyp.14685
• Languages: English
• ISSNs: 0885-6087

Abstract

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 anti‐clockwise 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. Abstract : This study proposes a framework to characterize and classify runoff events relying on the hysteresis analysis of the relationship between streamflow and depth to water table. Three main clusters of rainfall‐runoff events were identified, each associated to specific hydro‐meteorological characteristics of the events. This hysteresis‐based classification can be used for the analysis of runoff generation processes, for comparing different catchment response to storm events, as well as for providing indications for hydrological modelling.