FLOOD FREQUENCY ANALYSIS OF RIVER SWAT AT CHAKDARA GUAGE STATION

Abstract

This paper reviews the flood frequency characteristics of the river Swat at Chakdara Station using Weibull, Gumble Flood Frequency Factor method, Gumble Analytical method and Log Pearson Type III method for the design of permanent hydrologic and Hydro-engineering facilities on 100 years recurrence interval. These methods are based on the previous 49 years annual peak discharge data for Chakdara Guage station,the results show that for 100 years recurrence interval, Gumble Frequency Factor method is comparatively the best method for the design of permanent hydraulic structure at Chakdara and downstream of this station, but for short period of time Log Pearson Type III method is best, where no permanent structures are required. After assessing the risk of Bridge at Chakdara station and Amandara Headworks down stream of chakdara station, it is observed that these structures are over designed and hence safe from high floods for long period of time