ANNOUNCEMENTS
Flood in urban areas is an expected problem for many areas of north east India. In Assam, Guwahati has serious problem of urban flooding. This situation was expected every monsoon of the season due to heavy rainfall and improper drainage network of the city.
This study presents the catchment level analysis for urban flood for the flood prone locations of Guwahati city. In this study, the flood prone location for the city of Guwahati has been identified. With the invention of geospatial techniques, the role of DEM has become indispensable in the water resources studies. Digital Elevation Model is an important data for raster analysis and as well as for water resources application. The available DEMs (SRTM-30m, ASTER-30 and CARTOSAT version 3-10m) are used to delineate the area of catchment corresponding to the flood prone locations. This study has adopted a unique technique for the generation of Hybrid DEM using the topographic maps and available DEMs. Hybrid DEM has been used to delineate the accurate boundaries of catchment areas with respect to flood prone location. The precipitation information has been utilized to every catchment of the flood-prone areas, and analysis the precipitation design before the flood event day in the time of 2015, 2016 and 2017. Day by day rainfall data has been utilized for anticipating the edge precipitation for each flood-prone area for the year 2015, 2016 and 2017. The result depicts that 33mm threshold rainfall for Anil Nagar, Tarun Nagar, Nabin Nagar, Lachit Nagar, Birubari, Paltan bazar, G.N.B. road for the year of 2015, for the catchment of Rajgarh road, G.S. road, Chatribari and Panjabari found that threshold rainfall value are different for each of these flood prone locations. The threshold rainfall values have changed in 2016 and 2017 for the catchments of identified flood prone location. This study has used Remote Sensing and the Geographic Information Systems techniques used to delineation of catchment boundaries. In this study a challenge has been made to quantitatively define the impact of precipitation on the flood prone locations of Guwahati by generating the hybrid DEM.
Keywords: Urban flood, Flood prone areas, DEM, Catchment, Hybrid DEM
