Flood Risk and Impact Analysis of Varanasi City Region, India (original) (raw)

Varanasi city has spread from its original place of origin over the natural levee into the flood basin and on to the low-level floodplain. More often the city of Varanasi suffers due to storm water logging than due to flood from the Ganga river along the bank of which it is situated. Especially during 2013 and 2016 there was large scale inundation of many parts of Varanasi city both due to river flood waters as well as storm water logging. With the knowledge of field observations during these two (2013 and 2016) flood years using Survey of India topographic maps with 2m (north-western part of the city) and 5m (entire city) contour interval and with 1m DEM created using 4000 Differential Global Positioning System (DGPS) points together with several spot heights and benchmarks from Survey of India topographic maps, flood zones are digitized on very high resolution remote sensing data. Contour flooding is shown at different intervals of elevation. The flood zones and the expected contour flooding are superposed on the city map showing built up area. The extent of area, the number of houses and the number of people affected in each of the flood zones is worked out.