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

Abstract

A flood forecasting system has been developed using MIKE11river-modeling software modules rainfall-runoff (RR) {[}orNedbor-Afstromnings model (NAM)], hydrodynamic (HD), and floodforecasting (FF) for the Jamuneswari river catchment of the northwesternpart of Bangladesh. The 3-arc second shuttle radar topography mission(SRTM) digital elevation model (DEM) version 4.0 and the D8 method ofArcGIS9.3 have been used to delineate river network and catchmentbounderies, which are required for MIKE 11 model setup. The EuropeanCentre for Medium-Range Weather Forecast (ECMWF) model-forecastedrainfall data have been used in MIKE 11 NAM-HD modules to increase theforecast lead time to 72 h. Errors in forecast results have beenassessed by computing efficiency index, coefficient of correlation,volume error, peak error, and peak time error. Integration of the MIKE11 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 alongwith the integrated MIKE 11 NAM and HD modules to minimize error in theforecasted result. The efficiency index, volume error, peak error, andpeak 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 bythe MIKE 11 FF module, results were calculated as 0.989, -0.005%,0.158%, and 0.00 h. Inputting the ECMWF-forecasted rainfall, theupdated forecasting system determined the efficiency index, volumeerror, peak error, and peak time error as 0.92, 0.008%, 0.87%, and0.00% 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 floodforecasting system described in this case study are generic and can beapplied under similar geographic conditions in other locationsworldwide. In Bangladesh, decision makers will have more time to developresponses to imminent the flooding as a result of the increased forecastlead time provided by the analysis method described in this case study.DOI: 10.1061/(ASCE)HE.1943-5584.0000565. (C) 2012 American Society ofCivil Engineers.