Integrating Precipitation Nowcasting in a Deep Learning-Based Flash Flood Prediction Framework and Assessing the Impact of Rainfall Forecasts Uncertainties

Flash floods are among the most immediate and destructive natural hazards. To issue warnings on time, various attempts were made to extend the forecast horizon of flash floods prediction models. Particularly, introducing rainfall forecast into process-based hydrological models was found effective. However, integrating precipitation predictions into flash flood data-driven models has not been addressed yet. In this endeavor, we propose a modeling framework that integrates rainfall nowcasts and assesses the impact of rainfall predictions uncertainties on a Deep Learning-based flash flood prediction model. Compared to the Persistence and ARIMA models, the LSTM model provided better rainfall nowcasting performance. Further, we proposed an Encoder-Decoder LSTM-based model architecture for short-term flash flood prediction that supports rainfall forecasts. Computational experiments showed that future rainfall values improved flash floods’ predictability for extended lead times. We also found that rainfall underestimation had a significant adverse effect on the model’s performance compared to rainfall overestimation.