Flood Assessment and Hazard Mapping Using Remote Sensing & GIS Techniques for Chamoli District, Uttarakhand

Understanding of rainfall is an important issue for Uttarakhand, India which having varied topography and due to that extreme rainfall causes quick runoff which warns structural and functional safety of large structures and other natural resources. In this study the attempt has been made to understand the Flood hazard index of the Chamoli district. Chamoli being the highly flood prone region of the state was selected as the study region. The study area lies between 30 - 31? N latitude and 79 - 80? E longitude. The satellite data was ortho - rectified and the study area was extracted using district boundary. The vegetation type/land use map was prepared using on - screen visual interpretation technique. The multi - flood time series dataset was used for preparation of Digital Elevation Model. Geographical Information System was used for identification of flood prone areas which were classified with zone - wise. A flood frequency map was developed using the multi - date Landsat satellite imagery. The classified vegetation type/land use map from 2010 - 2019 was overlaid to find out the frequency of the flood. Flood affected areas were classified into very low, low, medium, high, very high and extremely high based on vulnerability to the potential of flood hazard. The areas were further categorized, based on the vulnerability of flood viz; extremely high (6) very high (5), high (4), medium (3), low (2) and very low (1) respectively.