Towards reconstruction of the flow duration curve: development of a conceptual framework with a physical basis

Abstract

Abstract. In this paper we investigate the climatic and landscape controls on the flow duration curve (FDC) with the use of a physically-based rainfall-runoff model. The FDC is a stochastic representation of the variability of runoff, which arises from the transformation, by the catchment, of within-year variability of precipitation that can itself be characterized by a corresponding duration curve for precipitation (PDC). Numerical simulations are carried out with the rainfall-runoff model under a variety of combinations of climatic inputs (i.e. precipitation, potential evaporation, including their within-year variability) and landscape properties (i.e. soil type and depth). The simulations indicated that the FDC can be disaggregated into two components, with sharply differing characteristics and origins: the FDC for surface (fast) runoff (SFDC) and the FDC for subsurface (slow) runoff (SSFDC), which included base flow in our analysis. SFDC closely tracked PDC and can be approximated with the use of a simple, nonlinear (threshold) filter model. On the other hand, SSFDC tracked the FDC that is constructed from the regime curve (i.e. mean monthly runoff), which can be closely approximated by a linear filter model. Sensitivity analyses were carried out to understand the climate and landscape controls on each component, gaining useful physical insights into their respective shapes. In particular the results suggested that evaporation from dynamic saturated areas, especially in the dry season, can contribute to a sharp dip at the lower tail of the FDCs. Based on these results, we develop a conceptual framework for the reconstruction of FDCs in ungauged basins. This framework partitions the FDC into: (1) a fast flow component, governed by a filtered version of PDC, (2) a slow flow component governed by the regime curve, and (3) a correction to SSFDC to capture the effects of high evapotranspiration (ET) at low flows.

Estimating flow duration curve in the humid tropics: a disaggregation approach in Hawaiian watersheds

“…The effectiveness of their framework was later confirmed in United States catchments by exploring the physical controls of regional patterns of FDCs Ye et al, 2012). As suggested by Yokoo and Sivapalan (2011), the high flow part of a FDC is highly responsive to precipitation. If so, the Curve Number (CN) method can be used in estimating the high flow part firstly because it is simple and convenient to use (Tedela et al, 2012) and secondly it estimates runoff based on a single CN parameter with an empirical precipitation and runoff relationship.…”

“…Based on the proposed framework by Yokoo and Sivapalan (2011), the MMF was used in estimating flows in the FDC middle component. Therefore, the FDCs of daily measured discharge (Q m ) and MMF were plotted and the two quantities were analyzed at the middle part.…”

“…Therefore, this study aims to develop a methodology for estimating the shape of a FDC in Hawaii Island watersheds following the framework of Yokoo and Sivapalan (2011). Towards this goal, the present study investigates (1) if we can estimate the middle flow part of a FDC from MMF and (2) how can we estimate the high flow part of a FDC from daily precipitation data and the CN method in well-gauged Hawaiian watersheds.…”

“…Its simplicity and ability to project an image of combined watershed information regarding runoff variability leads to it having many applications (Vogel and Fennessey, 1995). As for such FDCs, Yokoo and Sivapalan (2011) suggested a framework for reconstructing FDCs in a modeling approach. They separated a FDC into fast and slow flow parts and suggested that a strong relationship may exist between fast flows and precipitation for the high flow part and slow flows and the mean monthly flow (MMF) for the other part.…”

Comparative analysis of hydrologic signatures in two agricultural watersheds in east-central Illinois: legacies of the past to inform the future

“…Lastly, the flow duration curve (FDC) plots daily streamflow magnitude (on a log scale) as a function of the percent of time it is exceeded. The FDC can be divided into 3 sections, with the upper third corresponding to flood events and the fast flow response of a catchment, the middle third to the slow flow response of the catchment and its regime curve, and the lower third the low flow response (Yokoo and Sivapalan, 2011). While the upper third of the FDC is mainly related to precipitation intensity, the lower third is more related to properties of the catchment itself .…”