Development of the Jamuneswari Flood Forecasting System: Case Study in Bangladesh

A flood forecasting system has been developed using MIKE11 river-modeling software modules rainfall-runoff (RR) [or Nedbor-Afstromnings model (NAM)], hydrodynamic (HD), and flood forecasting (FF) for the Jamuneswari river catchment of the northwestern part of Bangladesh. The 3-arc second shuttle radar topography mission (SRTM) digital elevation model (DEM) version 4.0 and the D8 method of ArcGIS9.3 have been used to delineate river network and catchment bounderies, which are required for MIKE 11 model setup. The European Centre for Medium-Range Weather Forecast (ECMWF) model-forecasted rainfall data have been used in MIKE 11 NAM-HD modules to increase the forecast lead time to 72 h. Errors in forecast results have been assessed by computing efficiency index, coefficient of correlation, volume error, peak error, and peak time error. Integration of the MIKE 11 HD module with the MIKE NAM module has improved the result by 10.84% for efficiency index, 20.7% for volume error, 25.61% for peak error, and 95.83% for peak time error. The MIKE 11 FF module was applied along with the integrated MIKE 11 NAM and HD modules to minimize error in the forecasted result. The efficiency index, volume error, peak error, and peak time error of the hindcast result, before updating by MIKE 11 FF, were calculated as 0.803, 0.505%, 2.58%, and 2 h, After updating by the MIKE 11 FF module, results were calculated as 0.989, -0.005%, 0.158%, and 0.00 h. Inputting the ECMWF-forecasted rainfall, the updated forecasting system determined the efficiency index, volume error, peak error, and peak time error as 0.92, 0.008%, 0.87%, and 0.00% for 24 h; 0.87, 0.231%, 0.507%, and 0.00 h for 48 h; and 0.84, 0.519%, and 0.000 h for 72 h. The steps for developing the flood forecasting system described in this case study are generic and can be applied under similar geographic conditions in other locations worldwide. In Bangladesh, decision makers will have more time to develop responses to imminent the flooding as a result of the increased forecast lead time provided by the analysis method described in this case study. DOI: 10.1061/(ASCE)HE.1943-5584.0000565. (C) 2012 American Society of Civil Engineers.