FLOODPLAIN MAPS PREPARATION WITH AUTOCAD CIVIL 3D AND OPEN SOURCE SOFTWARE

Significant floods all over the world, including Romania and Bulgaria, have occurred in the last years as result of climate change and extreme meteorological phenomena manifestation. Overland flooding, the most common type of flooding event usually occurs when rivers or streams overflow their banks as a result of heavy rainfalls or fast snowmelt. In European Union, flood defence management is an essential part of the integrated water management and the European Commission Directive 2007/60, regarding the estimation and management of the flood risks, states that all the member countries have to achieve flood risks maps till the end of 2013. Flood hazard maps must be created to help the communities in finding out which are the different flood risk areas and to provide public awareness and useful information to local authorities and decisions makers in case of possible flood events. Flood risk areas should be also identified and delimited for future land use and development. The development of risk maps assumes the existence and access to extensive databases, detailed maps and GIS data depots for most of the necessary information, as well as expensive software (i.e. ArcGIS, MIKE) and skilled experts. Unfortunately, these criteria are not always met. This paper presents an alternative method to prepare preliminary floodplain maps, based on the use of Autodesk products and Open Source software. The purpose of the method is to introduce basic satellite image display and processing techniques using open source software and freely available satellite data to allow floodplain maps development without using expensive software and unaffordable data. The method consists in DTM (Digital Terrain Model) generation, rivers and watershed delineation and hydraulic modelling in order to generate floodplain maps.