Prediction of surface and subsurface flow in catchments using the GIUH

Abstract

Flood estimation in ungauged catchments is one of the important points in designing hydraulic structures. In this paper, the geomorphological instantaneous unit hydrograph (GIUH) model previously suggested by Lee and Chang to estimate the surface and subsurface hydrographs of catchments was extended. To improve the model, a new equation was presented based on the Dunne–Black mechanism for separating the overland into saturated and unsaturated zones. Two new factors, soil thickness and rainfall recharge rate, were taken into account in calculations of the saturation zone length, and the travel times of surface and subsurface flows. The effect of saturation upon subsurface flow travel time was regarded in the GIUH model. The convolution equation for the estimation of the direct run‐off hydrograph (DRH) was improved according to the response of subsurface flow to rainfall recharge, and the response of surface flow to excess rainfall. The final model was employed to predict the surface and subsurface flows in the Kasilian catchment. The performance of the GIUH was found to be more effective, as reflected in lower root mean square error (1.24 m3/s) and relative mean absolute error (0.07). The average error was 8.78% to estimate the flood peak. In general, the efficiency of the model in the estimation of DRH was assessed as proper.

Comparing Three Hydrological Models for Flash Flood Simulations in 13 Humid and Semi-humid Mountainous Catchments

“…Individual models tend to have various strengths in catchments with different runoff generation mechanisms and modes (Sabzevari et al 2013;Petroselli 2020). It is acknowledged that excess infiltration runoff generation prevails in semi-humid and arid catchments.…”

Separation of surface flow from subsurface flow in catchments using runoff coefficient

“…However, in hilly catchments with very permeable soil or dense vegetation cover, the rate of infiltration is high and can lead to rapid subsurface flow. In such catchments, subsurface flow can enter streams at the lower part of hillslopes and contribute effectively to direct flow (Singh, 1988, Sabzevari et al, 2013.…”

“…Numerical methods give good accuracy, but most hydrologists want simpler methods. Some hydrological models have also been used to estimate SSF (Robinson and Sivapalan 1996;Lee and Chang 2005;Sabzevari et al 2013;Sabzevari and Noroozpour, 2014). Lee and Chang (2005) developed the geomorphological instantaneous unit hydrograph (GIUH) model for predicting SSF.…”

“…Lee and Chang (2005) used the GIUH model to separate SF and SSF in the Heng-Chi basin, Taiwan. Sabzevari et al (2013) modified the Lee and Chang (2005) model by calculating the SSF hydrograph of the catchment through convoluting the subsurface GIUH model in the infiltration hyetograph. In their modified version, a more accurate saturation model was used to predict SF and SSF according to the Dunne-Black mechanism.…”

“…In their modified version, a more accurate saturation model was used to predict SF and SSF according to the Dunne-Black mechanism. Sabzevari et al (2013) applied the modified model in the Kasilian catchment, Iran, to separate SF and SSF. Sabzevari and Noroozpour (2014) examined the role of hillslope shape and profile curvature on SF and SSF in complex hillslopes and applied a new complex saturation model to separate the saturation region.…”