Flood is a natural hazard resulting from extreme meteorological events which cause an unexpected threat to human lives and properties. Flood stems from the probability that a major hazard event will occur in a well-defined area and it will impacts negatively, in particular on the people and their welfare. Flood protection planning is a very important step which helps not only to rescue the people affected by flood but also to mitigate the effects of these calamitous events and to take necessary preventive measures. Geographic Information System (GIS) is a useful tool to carry out methods of environmental management. With Remote Sensing (RS) techniques, GIS helps in (i) bringing forth hidden patterns in a dataset (ii) performing queries (iii) storing, editing and retrieving (converting) data in maps, (iv) preparing exceedingly ‘expressive’ maps to facilitate survey, spatial modeling, analysis and decisionmaking. This paper aims to take stock of the GIS capabilities which are particularly relevant to Flood projection for determining a suitable location to build a dam on the basis of 50 years projected data and determining flood vulnerability in Sirajganj area, in Bangladesh, by using a vulnerability analysis.