Verification of two hydrological models for real-time flood forecasting in the Hindu Kush Himalaya (HKH) region

Abstract

The Hindu Kush Himalayan region is extremely susceptible to periodic monsoon floods. Early warning systems with the ability to predict floods in advance can benefit tens of millions of people living in the region. Two web-based flood forecasting tools (ECMWF-SPT and HIWAT-SPT) are therefore developed and deployed jointly by SERVIR-HKH and NASA-AST to provide early warning to Bangladesh, Bhutan, and Nepal. ECMWF-SPT provides ensemble forecast up to 15-day lead time, whereas HIWAT-SPT provides deterministic forecast up to 3-day lead time covering almost 100% of the rivers. Hydrological models in conjunction with forecast validation contribute not only to advancing the processes of a forecasting system, but also objectively assess the joint distribution of forecasts and observations in quantifying forecast accuracy. The validation of forecast products has emerged as a priority need to evaluate the worth of the predictive information in terms of quality and consistency. This paper describes the effort made in developing the hydrological forecast systems, the current state of the flood forecast services, and the performance of the forecast evaluation. Both tools are validated using a selection of appropriate metrics in measurement in both probabilistic and deterministic space. The numerical metrics are further complemented by graphical representations of scores and probabilities. It was found that the models had a good performance in capturing high flood events. The evaluation across multiple locations indicates that the model performance and forecast goodness are variable on spatiotemporal scale. The resulting information is used to support good decision-making in risk and resource management.

Using Earth observation and geospatial applications for disaster preparednessv - training manual

“…The HKH is one of the most vulnerable floodprone regions (Tsering et al 2022). With clear evidence of climate change, the region is now facing even more intense and frequent flood events.…”

“…The tool provides predicted estimates for flash floods from localised extreme weather phenomena like convective storms and thunderstorms. The FFPT provides predicted estimates by routing the HIWAT rainfall predictions through the Routing Application for Parallel computation of Discharge (RAPID) model (Tsering et al 2022). This tool complements the information generated by HIWAT and can be used as part of a decision-support system for flood forecasting services.…”

Evaluation of Climatological Precipitation Datasets and Their Hydrological Application in the Hablehroud Watershed, Iran

“…Reanalysis datasets have been used in various fields such as meteorology [23,24], climatology [25,26], and environmental studies [27,28]. Recently, reanalysis datasets have also been used as input data or for calibration and evaluation data for hydrological modeling [29,30].…”