%0 Journal Article
%T Estimation of Peak Flood Discharge for an Ungauged River: A Case Study of the Kunur River, West Bengal
%A Suvendu Roy
%A Biswaranjan Mistri
%J Geography Journal
%D 2013
%I Hindawi Publishing Corporation
%R 10.1155/2013/214140
%X Due to unavailability of sufficient discharge data for many rivers, hydrologists have used indirect methods for deriving flood discharge amount, that is, application of channel geometry and hydrological models, for the estimation of peak discharge in the selected ungauged river basin(s) in their research/project works. This paper has studied the estimation of peak flood discharge of the Kunur River Basin, a major tributary of the Ajay River in the lower Gangetic plain. To achieve this objective, field measurements, GIS technique, and several channel geometry equations are adopted. Three important geomorphic based hydrological models¡ªmanning¡¯s equation, kinematic wave parameter (KWP), and SCS curve number (CN) method¡ªhave been used for computing peak discharge during the flood season, based on daily rainfall data of September, 2000. Peak discharges, calculated by different given models, are 239.44£¿m3/s, 204.08£¿m3/s, and 146.52£¿m3/s, respectively. The hydrograph has demonstrated the sudden increase with heavy rainfall from the 18th to the 22nd of September, 2000. As a result, a havoc flood condition was generated in the confluence zone of Ajay and Kunur Rivers. This hydrograph might be not only successful application for flood forecasting but also for management of the lower Ajay River Basin as well as the downstream area of Kunur Basin. 1. Introduction In India most of the watersheds up to 500£¿km2 geographical area can be categorized as ungauged catchments [1]. Majority of river basins are either sparsely gauged or not gauged at all, where the lack of hydrological and catchment information makes obstruction for watershed planning [2]. As per Sing et al. [1], hydrological response from each catchment assists in flood routing vis-¨¤-vis in flood modeling and flood forecasting. Schumm [3] apprises that water and sediment discharge are the principal determinants of the dimensions of a river channel (width, depth, meander wavelength, and gradient). Physical characteristics of river channels, such as width/depth ratio, sinuosity, and pattern (braided, meandering, and straight) are significantly affected by the flow rate and sediment discharge. According to Bhatt and Tiwari [2], channel geometry method is an alternative mode of estimating flood discharge for regional flood frequency analysis. River bed characteristics¡ªchannel width, cross-section area, river bed gradient, and bank side slope¡ªare crucial parameters for alternative techniques of discharge estimation. In hydrology, the term ¡°peak discharge¡± stands for the highest concentration of runoff from the
%U http://www.hindawi.com/journals/geography/2013/214140/