chapter  6
Delineation and Zonation of Flood Prone Area Using Geo-hydrological Parameters: A Case Study of Lower Ghaghara River Valley
Pages 23

Zonation of ood prone area on the basis of ood magnitude and geomorphic features denotes the assessment of a river valley in terms of susceptibility of oods. e Landsat and Resourcesat-1 satellite images (1977, 1990 and 2008) and Landsat MSS derived inundated area (1982) and Dartmouth ood atlas (1998, 2005 and 2008) have been used for identiƒcation of the geomorphic units and ood prone area of the lower Ghaghara river valley. e magnitude of oods in the above mentioned years has been deƒned on the basis of their areal extent and duration of ooding. e ood prone area along the Ghaghara River (Ayodhya-Turtipar stretch) has been divided into three ood zones using overlay of ood layers of diŠerent magnitude and geomorphic features in the GIS environment. On the basis of geomorphic features, ood magnitude and frequency, vulnerability of hamlets in each ood zone has been assessed. e channel belt and active oodplain denote ood zone 1 which is regularly ooded in monsoon season (August to September). is zone has the most dynamic geomorphic features such as alluvial islands and mid-channel bars due to sedimentation in the channel belt. erefore, hamlet density is low in this zone while the vulnerability of hamlets therein is high. Flood zone 2 covers embankment protected part of the active oodplain which 1 Centre for the Study of Regional Development, School of Social Sciences, Jawaharlal Nehru University, New Delhi, India.