A hydrometeorological flood forecasting system for the Red and Ca rivers (China, Laos and Vietnam). Part II – Application and results

Applications and results of the hydrometeorological flood forecasting chain which has been setup for the Red River and the Ca River are briefly presented here. Five major floods occurred in the Red river in the 1971-2007 period and several floods occurred in the Ca river from 2006 to 2011, including the October 2010 disaster, were simulated with the BOLAM-MOLOCH-DIMOSHONG forecasting chain. The use of runoff observations at fourteen hydrometric stations in the Lo river, a major branch of the Red river, enabled the distributed model updating with an Extended Kalman Filtering, showing an improvement of flood forecasts compared to the results obtained with the rainfall-runoff model without hydrometric observations. Perspectives for improving the forecasting chain and for an operational implementation including surface observations and meteorological corrections using weather-types classification are discussed.