Development of rainfall intensity-duration-frequency relationships and nomographs for selected stations in Maharashtra, India

Abstract

The rainfall intensity-duration-frequency (IDF) relationship plays an important toolin planning,designing, evaluatingand operatingof water resource projects, water resources development and management.It is necessary to examine the location-specific relationship between rainfall components, intensity, duration and frequency due to their spatiotemporal variation. In this article, weinvestigate the relationship between the rainfall intensity and its components and develop nomographs for Washim, Chandrapur and Yeotmal districts in Maharashtra, India. We also studied the rainfall charts of various stations for maximum annual rainfall intensities of selected duration. The frequency lines are computed for the above locations.. An empirical studyisconducted to determine the value of constants ‘a’ and ‘b’ and that of ‘K’ (Nemec, 1973).The nomographs are also developed for the rainfall intensity-duration-frequency (IDF) relationships (Luzzadar, 1964). Adequacy of the results istested by statistical indices such as integral square error, correlation coefficient, percent absolute deviation and root mean square error. The variation between nomographic solutions and mathematical equations lies within the permissible limit, less than 20%.