River discharge prediction for ungauged mountainous river basins during heavy rain events based on seismic noise data

Shakti P.C,Kaoru Sawazaki

doi:10.1186/s40645-021-00448-1

Abstract

Several mountainous river basins in Japan do not have a consistent hydrological record due to their complex environment and remoteness, as discharge measurements are not economically feasible. However, understanding the flow rate of rivers during extreme events is essential for preventing flood disasters around river basins. In this study, we used the high-sensitivity seismograph network (Hi-net) of Japan to identify the time and peak discharge of heavy rain events. Hi-net seismograph stations are distributed almost uniformly at distance intervals of approximately 20 km, while being available even in mountainous regions. The Mogami River Basin in Northeastern Japan was selected as a target area to compare the seismic noise data of two Hi-net stations with the hydrological response of a nearby river. These stations are not located near hydrological stations; therefore, direct comparison of seismic noise and observed discharge was not possible. Therefore, discharge data simulated using a hydrological model were first validated with gauging station data for two previous rain events (10–23 July 2004 and 7–16 September 2015). Then, the simulated river discharge was compared with Hi-net seismic noise data for three recent events (10–23 July 2004, 7–16 September 2015, and 10–15 October 2019). The seismic noise data exhibited a similar trend to the time series of simulated discharge in a frequency range of 1–2 Hz for the selected events. Discharge values predicted from the noise data effectively replicate the simulated discharge values in many cases, especially the timing and amount of peak discharge.Simulated and predicted discharge near NIED Hi-net seismic stations in the Mogami River Basin for the event of October 2019 (Typhoon Hagibis).

Highlights

River discharge is defined as the total volume of water flowing through a river at any given point; it is an important hydrological parameter for planning and decision making of many water-based development activities
The aim of this study is to demonstrate the application of seismic data for predicting the discharge in an ungauged river basin during a heavy rain event
The simulated discharge was compared with the observed discharge at several stations in the basin for previous heavy rain events

Summary

Introduction

River discharge is defined as the total volume of water flowing through a river at any given point; it is an important hydrological parameter for planning and decision making of many water-based development activities. Regular monitoring of river discharge is lacking for mountainous river basins, which are known as ungauged river basins. To predict and prevent water-related disasters in a river basin, regular measurement of river discharge is crucial, during extreme rain events; this is because it can determine the flow capacity of the river section in response to heavy rainfall (Marchi et al 2010). The time lag between rainfall and flooding is short, especially in small river basins. In such a situation, high temporal estimation of river discharge is necessary for estimating the flood disaster level in a downstream section, and appropriate measures should be taken in a timely fashion for disaster prevention and management. Various indirect methods are available for quantifying and monitoring river discharge at given points (Bjerklie et al 2005; Marchi et al 2010; Dobriyal et al 2017; Anthony et al 2018; Kebede et al 2020; Shi et al 2020)

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Conclusion