Development of Medium Range Ensembles Flood Forecasts
Early warning is a key element for disaster risk reduction. In recent decades, there has been a major advancement in medium range and seasonal forecasting flood forecasting skills. This progress provides a great opportunity to improve advisories for early action and planning for flood hazard. This approach can facilitate a proactive rather than a reactive management of adverse consequences of flood events. In agricultural sector, for instance, farmers can take diversity of options such as changing cropping patterns, putting fertilizer or irrigation and planting timing. An experimental medium range (1-10 days) flood forecasting model has been developed for Bangladesh by our group providing 51 set of discharge ensembles forecasts of one to ten days with significant persistence and high certainty. This type of forecast could assist farmers and other stakeholders for differential preparedness activities. These ensembles probabilistic flood forecast has been customized based user-needs for the community level application focused on agriculture. The framework allows users to interactively specify the objectives and criteria that are germane to a particular situation, obtaining possible management options, and the exogenous influences that should be taken into account for decision making. Risk and vulnerability assessment were conducted through community consultations. The forecast lead time requirement, user-needs, impacts and management options for crops and livestock were identified through focus group discussions, informal interviews and community surveys. This paper illustrates potential applications of ensembles probabilistic medium range flood forecast which are not a common practice globally.