Continental and global scale flood forecasting systems

Abstract

Floods are the most frequent of natural disasters, affecting millions of people across the globe every year. The anticipation and forecasting of floods at the global scale is crucial to preparing for severe events and providing early awareness where local flood models and warning services may not exist. As numerical weather prediction models continue to improve, operational centers are increasingly using their meteorological output to drive hydrological models, creating hydrometeorological systems capable of forecasting river flow and flood events at much longer lead times than has previously been possible. Furthermore, developments in, for example, modelling capabilities, data, and resources in recent years have made it possible to produce global scale flood forecasting systems. In this paper, the current state of operational large-scale flood forecasting is discussed, including probabilistic forecasting of floods using ensemble prediction systems. Six state-of-the-art operational large-scale flood forecasting systems are reviewed, describing similarities and differences in their approaches to forecasting floods at the global and continental scale. Operational systems currently have the capability to produce coarse-scale discharge forecasts in the mediumrange and disseminate forecasts and, in some cases, early warning products in real time across the globe, in support of national forecasting capabilities. With improvements in seasonal weather forecasting, future advances may include more seamless hydrological forecasting at the global scale alongside a move towards multi-model forecasts and grand ensemble techniques, responding to the requirement of developing multi-hazard early warning systems for disaster risk reduction.

Application of Remote Sensing Data to Constrain Operational Rainfall-Driven Flood Forecasting: A Review

“…Simple conceptual models have been preferred in operational applications, but challenges also exist in matching remote sensing data and model variables with vague physical meaning. For detailed background in modelling techniques in flood forecasting, it is recommended to refer to Sene [1] and Emerton et al [3]. According to the approaches of combining models and data, the applications/studies can be classified into direct forcing, batch calibration and data assimilation.…”

“…Generally, fluvial floods are formed in the following series of processes: runoff generation, runoff concentration, streamflow propagation and floodplain inundation [1,2]. Most operational fluvial flood forecasting systems only simulate the first three processes, to provide water level and streamflow forecasts [3]. The three processes are typically simulated through coupled rainfall/snowmelt-runoff models and hydrological routing models [3][4][5][6][7][8][9].…”

“…Most operational fluvial flood forecasting systems only simulate the first three processes, to provide water level and streamflow forecasts [3]. The three processes are typically simulated through coupled rainfall/snowmelt-runoff models and hydrological routing models [3][4][5][6][7][8][9]. Only few systems incorporate more sophisticated hydraulic models to assist streamflow propagation simulation which allows the forecasting of floodplain inundation as well [10].…”

An operational procedure for rapid flood risk assessment in Europe

“…The availability of real-time operational systems for assessing potential consequences of forecasted events would be a substantial advance in helping emergency response (Molinari et al, 2013), and indeed flood risk forecasts are increasingly being requested by end users of early warning systems (Emerton et al, 2016;Ward et al, 2015). At a local scale, the joint evaluation of flood probabilities and consequences may not only increase preparedness of emergency services but also allow cost-benefit considerations for planning and prioritizing response measures (e.g.…”

Methods and tools to support real time risk-based flood forecasting - a UK pilot application

“…In recent years, such deterministic model-based flood forecasting systems have been established all over the world for different spatial scales. Examples are: the Global Flood Awareness System (GloFAS) [4] and Global Flood Forecasting and Information System (GLOFFIS) [5] on a global scale; the European Flood Alert System [6] on a continental scale; the flood forecasting system of England, Scotland and Wales [7] on a national scale; and the forecasting system for the Salado Creek in Texas [8] on a basin scale. Further examples are provided in [9,10].…”