Natural disaster like flood and water logging is a worldwide phenomenon. In India, during intense monsoon, not only the rural areas but the urban areas are also badly affected by water logging. Midnapore Kharagpur Development Authority (MKDA) planning region of West Bengal is not an exception. Application of GIS for real time rainfall runoff modeling is rapidly advancing and soon will be the frame work of a predictive early flood warning system. This research is a fundamental step to assess flood inundation and water logging vulnerability of MKDA and their real time display on map, which can aid the prioritization process of MKDA authority in their emergency sewerage clearance and mechanical water ejection during heavy downpour.
FLO-2D simplified the process of analytical solution in inundation modeling. It is a two-dimensional flood routing model that has been used to simulate runoff (channel flow, unconfined overland flow, street flow etc.) over complex topography. Spatial information on land use land cover, elevation, slope magnitude, slope direction, soil condition, and sewerage condition were incorporated in the model design; finally rainfall duration and amount are used as input to get the inundated areas as output. Most of the maps have been displayed as either grid element plots, line contour maps, and shaded contour maps. Shape files for importing results to GIS are automatically generated for most of the Mapper plots. By importing the DTM ground elevation points into Mapper and subtracting the ground elevation from the FLO-2D predicted maximum grid element water surface elevation, flow depths are computed for every DTM point. Model generated inundated areas of a real storm have been compared with actual inundated area extracted from microwave imagery (RADAR SAT-1) of the same dateand with primary field survey map for validation of the model.