"The influence of rainfall movement on the peak and shape of basin hydrograph has. been long recognized. Early literature results highlight that a storm moving in the downstream direction. produces a greater peak discharge, compared with a storm moving upstream. Recent studies pointed out. that the assumption of uniform rainfall can lead to a potential underestimation of flood risks, and that this. can be hugely enhanced by rainstorm movement, also depending on regional characteristics of storm. dynamics.. In this study we propose an analytical approach to investigate the influence of the pattern of moving. rainstorms on the hydrological response of a river basin. We analyze the response of the basin to an. excess rain field (rain contributing to direct runoff), which is assumed to be variable in space and time;. catchment response to an instantaneous input of uniform rainfall is assumed to be fully characterized by. the time-invariant distribution of the travel time of water particles within the basin.. Our results show how, in the framework assumed herein, peak flows magnification is a consequence of a. rainstorm moving over the basin in synchrony with surface flows. This exact superposition, which is called. "resonance" condition, depends on the relative size of the rainstorm with respect to basin size. In particular,. for storm sizes much smaller than the dimension of the catchment, the resonance condition occurs for. infinite combinations of the direction and speed of the moving rainstorm. For illustration purposes, we. present and discuss a case study based on the "open-book" idealized catchment."
DI LAZZARO, M., Volpi, E., Fiori, A. (2012). Influence of rainstorm movement on basin hydrographs: theoretical analysis of resonance conditions. In AGU Fall Meeting, San Francisco, December 2012..
Influence of rainstorm movement on basin hydrographs: theoretical analysis of resonance conditions
DI LAZZARO, MICHELE;VOLPI, ELENA;FIORI, ALDO
2012-01-01
Abstract
"The influence of rainfall movement on the peak and shape of basin hydrograph has. been long recognized. Early literature results highlight that a storm moving in the downstream direction. produces a greater peak discharge, compared with a storm moving upstream. Recent studies pointed out. that the assumption of uniform rainfall can lead to a potential underestimation of flood risks, and that this. can be hugely enhanced by rainstorm movement, also depending on regional characteristics of storm. dynamics.. In this study we propose an analytical approach to investigate the influence of the pattern of moving. rainstorms on the hydrological response of a river basin. We analyze the response of the basin to an. excess rain field (rain contributing to direct runoff), which is assumed to be variable in space and time;. catchment response to an instantaneous input of uniform rainfall is assumed to be fully characterized by. the time-invariant distribution of the travel time of water particles within the basin.. Our results show how, in the framework assumed herein, peak flows magnification is a consequence of a. rainstorm moving over the basin in synchrony with surface flows. This exact superposition, which is called. "resonance" condition, depends on the relative size of the rainstorm with respect to basin size. In particular,. for storm sizes much smaller than the dimension of the catchment, the resonance condition occurs for. infinite combinations of the direction and speed of the moving rainstorm. For illustration purposes, we. present and discuss a case study based on the "open-book" idealized catchment."I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
