Citation

Pal JR. J. Inst. Eng. India Ser. A 2023; 104(4): 983-995.

Copyright

(Copyright © 2023, Holtzbrinck Springer Nature Publishing Group - BMC)

DOI

10.1007/s40030-023-00754-5

PMID

unavailable

Abstract

While planning and designing the hydraulic structures such as barrages, dams, reservoirs, spillways, tank embankments and bridges proper safeguards must be made for the safe passage of the maximum peak flood expected. Many flood frequency methods are prevalent for estimating floods of various return periods. These methods are based on standard probability distribution functions. The assumption is that the annual maximum flood discharge at a certain location follows one of the standard probability distribution functions, for a catchment of a given region. The main objective of this paper is to depict a methodology to calculate the maximum probable flood discharge at a Barrage Site, where historic maximum flood discharge data is not available, but it may be available at any site downstream. The methodology depicted in this paper is to first use Dicken's Formula to get peak flood discharge at the barrage site using the available data from downstream site, and then use the Gumbel's Method for the flood frequency analysis. The Gumbel's distribution or extreme value distribution is one of the commonly used distributions in India for flood frequency analysis and point rainfall frequency analysis. This paper shows how the above methodology has been used to calculate the maximum probable flood discharge at Tiuni Barrage Site, where maximum flood discharge for 40-100 years is not available, but data available at the downstream Kishau Dam site has been used. Using Gumbel's distribution, the calculated probable flood discharge for return period of 100 years is 5486 m3/s and for return period of 1000 years is 7928 m3/s, as shown in this paper can be used for Hydraulic Design and Structural design of Barrage at Tiuni, respectively. Mean of annual flood peak for 37 years in the river is 1207 m3/s, which is around a return period of about 2.25 years. This shows that the pattern of scatter is narrow in the graph of the Reduced Variate versus annual flood peak in the river. Hence prediction of flood in the basin is nearly accurate and can be utilized in designing of important hydraulic structures and planning purposes.

Language: en

Keywords

Barrage; Catchment; Dam; Discharge; Flood; Frequency; Geology; Himalayas; Hydroelectric; Hydrology; Reservoir