DEVELOPMENT OF FLOOD HAZARD INFORMATION FOR MITIGATION PURPOSE IN KHEDA CITY USING REMOTELY SENSED DATA: A CASE STUDY

摘要

Flood disasters are among the world's most frequent and damaging types of disaster. Throughout the human history floods have been an integral part of the civilization. Still men have not quite coped well to live with floods. This can be attributed to the complex nature of the flood as well as the diverse response to it. It is always hard to tell which one is the better policy and strategy, to fight floods or to learn to live with the floods. Flood hazards result from a combination of physical exposure and human vulnerability to a geophysical process. Flood plain mapping is an applied method in river engineering discipline and is essential for prediction of flood hazard and flood inundation risk assessment. Accurate delineation of flood extents and water depths within the floodplain is necessary to develop flood hazard information of the river system, for the purpose of floodplain management, evaluation of river training practices, flood insurance studies, urban planning and other practices on land and property potentially affected by flooding. The research presents a straight forward approach for processing output of HEC-RAS hydraulic model, to enable flood plain mapping and analysis in the Arc View GIS. The methodology is applied to Kheda city situated on the banks of Vatrak river, located in Gujarat. A flood plain view is developed using base map. A DEM is used as an input in ArcGIS from which cross-sections are extracted in HEC-RAS. Hydraulic analysis is performed in the software which generates flood extent maps along with flood depth profiles for different return periods. Through these maps the can estimate the area inundated by flood of the city. Overall, the result of the research indicates that GIS along with HEC-RAS provides an effective environment for flood plain mitigation purpose.