Stormflow generation: A meta‐analysis of field evidence from small, forested catchments

Abstract

Combinations of runoff characteristics are commonly used to represent distinct conceptual models of stormflow generation. In this study, three runoff characteristics: hydrograph response, time source of runoff water, and flow path are used to classify catchments. Published data from the scientific literature are used to provide evidence from small, forested catchments. Each catchment was assigned to one of the eight conceptual models, depending on the combination of quick/slow response, old/new water, and overland/ subsurface flow. A standard procedure was developed to objectively diagnose the predominant conceptual model of stormflow generation for each catchment and assess its temporal and spatial support. The literature survey yielded 42 catchments, of which 30 catchments provide a complete set of qualitative runoff characteristics resulting in one of the eight conceptual models. The majority of these catchments classify as subsurface flow path dominated. No catchments were found for conceptual models representing combinations of quick response-new water-subsurface flow (SSF), slow-new-SSF, slow-old-overland flow (OF) nor new-slow-OF. Of the 30 qualitatively classified catchments, 24 provide a complete set of quantitative measures. In summary, the field support is strong for 19 subsurface-dominated catchments and is weak for 5 surface flow path dominated catchments (six catchments had insufficient quantitative data). Two alternative explanations exist for the imbalance of field support between the two flow path classes: (1) the selection of research catchments in past field studies was mainly to explain quick hydrograph response in subsurface dominated catchments; (2) catchments with prevailing subsurface flow paths are more common in nature. We conclude that the selection of research catchments needs to cover a wider variety of environmental conditions which should lead to a broader, and more widely applicable, spectrum of resulting conceptual models and process mechanisms. This is a prerequisite in studies where catchment organization and similarity approaches are used to develop catchment classification systems in order to regionalize stormflow.

Direct Channel Precipitation and Storm Characteristics Influence Short‐Term Fallout Radionuclide Assessment of Sediment Source

“…The conceptual model presented here aligns with hydrologic studies showing the importance of direct precipitation and throughfall to water fluxes from forested catchments on the event scale (Dewalle et al, ; Dunne & Black, ; Pearce et al, ). In particular, event‐scale water fluxes out of watersheds are often dominated by subsurface pathways in forested setting (Barthold & Woods, ; Jencso et al, ; Shanley et al, ); hence, direct precipitation and throughfall onto the channel area would dominate the FRN input to the stream, as both 7 Be and 210 Pb xs would sorb onto the soil and decay during infiltration prior to reaching the stream via a subsurface pathway. Our method of computing the radionuclide activity balance by weighting the open and canopy‐specific throughfall chemical deposition fluxes by their respective channel areas aligns with the decades‐old method for computing such depositional fluxes for stable isotopes (e.g., DeWalle & Swistock, ).…”

A hydrochemical approach to quantify the role of return flow in a surface flow‐dominated catchment

“…Understanding stormflow generation remains a central research issue in hydrology (Burt & McDonnell, ). Surface flow paths are recognized as important contributors to stormflow (Bonell & Gilmour, ; Dunne & Black, ; Elsenbeer & Lack, ; Eshleman, Pollard, & Kuebler O'Brien, ; Johnson, Lehmann, Couto, Novaes Filho, & Riha, ; Slattery, Gares, & Phillips, ; Soulsby, Rodgers, Smart, Dawson, & Dunn, ), yet our ability to conceptualize hydrologic processes in catchments where surface flow paths prevail remains limited, particularly when compared to catchments dominated by subsurface flow paths (Barthold & Woods, ).…”

Discovery of zero‐order basins as an important link for progress in hydrogeomorphology

“…Such heterogeneity is also apparent when comparing various hillslope plots, even with similar topographic conditions (Bachmair, Weiler, & Troch, 2012). Based on systematic analysis of various studies, Barthold and Woods (2015) suggest that spatially extensive surface and subsurface measurements should be considered at hierarchical scales to assess the dominant flow paths (subsurface versus surface). Therefore, it is widely recognized that observations at one scale (or one location of a zero-order basin) cannot be simply extrapolated to wider scales (e.g., Sidle, Gomi, Loaiza-Usuga, & Jarihani, 2017).…”