Extended-range hydrometeorological forecasting for improved flood early warning in Bangladesh.

Bangladesh is located at the downstream of three big River Basins- Ganges-Brahmaputra and Meghna (GBM) (Figure1). The rivers are mostly originated from world highest Himalayan mountain range. The monsoon precipitation from June to September is the main source of water for river systems in Bangladesh. Heavy rainfall in the monsoon period is the main causes of flood, and it occurs almost every year with devastating one in every 5 to 8 years. It causes severe damage to agriculture, physical infrastructures and loss of human lives in Bangladesh. For instance, flood in 1988,1998,2004,2007 ,2010 ,2016 and 2017 can be mentioned as severe flooding years for Bangladesh. For flood management, Bangladesh has been taken both structural and non-structural measures. One of the main non-structural measures is flood forecasting and warning services. The objectives of flood forecasting is to enable and persuade people, community, agencies and organizations to be prepared for the flood and take necessary actions to increase safety and reduce damages of lives and properties. Its goal is to alert people on the eve of flood event.
Presently, Flood Forecasting and Warning Centre (FFWC) in Bangladesh is providing 3 to 5 days deterministic flood forecast based on the upstream boundary approximation. Moreover, it has also experimented 10 days probabilistic forecast using European Centre for Medium-Range Weather Forecasts (ECMWF) medium range weather forecast for the major river systems in Bangladesh.

Objectives.
The overall objective of the study is to develop extended range forecast for Bangladesh. The specific objectives of this research are as follows.

Topics for consideration include, but are not limited to:
*The limit of predictability of the South Asian monsoon - Land surface controls on floods flows including soil moisture, snow melt and evaporation.
*Parameterisation and physics of river routing models, particularly related to backwater effects at major river confluences.
*Improving statistical characteristics of probabilistic forecasts.
*Institutionalization aspects of seasonal river flow forecast schemes for Bangladesh in water resources assessment.
*Community level application of long-rage flood forecast.
*Develop framework for regional flood forecasting aspect in Ganges-Brahmaputra and Meghna Basin.