Flood frequency analysis of vaigai river

Abstract

Rivers are defined as drainage channels formed by the drain-off and newlinerunoff from watersheds due to rainfall or melting of snow at high altitudes. newlineThe formation and development of this well-defined drainage take years together. newlineVaigai river is the fourth largest river system in Tamil Nadu. It originates at the newlinehigher altitude of 1524m from Mean Sea Level (MSL) on the eastern slope at newlineGandamanaikan Zamin of Western Ghats and follows the natural slope of the newlineground and finally empties into the Palk Bay near Alagankulam, close to Pamban newlineBridge in Ramanathapuram District. It may cause devastation and trouble to newlinehuman beings, especially during the prevailing monsoon usually occurs in the newlinesecond week of June and ends in December. An occasional unexpected incessant newlinepouring is also expected cause the problem of floods due to the formation of newlineunusually severe critical hydrometeorological conditions over the catchment area. newline newlineFlood estimation is an essential component of hydrologic design and is newlinein the beginning stage of regulation to curb flooding by various measures of both newlinestructural and non-structural methods. The flood frequency analysis is one of the newlinebest non-structural methods and it is used to form a correlation between the newlinefrequency of flood and the magnitude of an event that it exceeds. The main newlineobjective of the present study is to perform flood frequency analysis in the Vaigai newlineriver basin to forecast peak discharge for any given return period. Before newlineperforming flood frequency analysis, detailed studies of the river basin are carried newlineout to identify the conditions of the physiographic factors that influence the newlinebehaviour of the river system. To perform this analysis, the gauging station located newlineupstream of the river basin was identified and the recorded daily flow in the newlinegauging station for periods of 24 years was collected, from these data, the annual newlinepeak flow for the periods of 24 years is obtained. newline