Rainfall intensity−duration−frequency curves for Ballowal Saunkhri in the Shivalik foot−hills of Punjab

Abstract

Rainfall is the result of complex atmospheric phenomena and it is a complicated temporal and spatial structure. Rainfall intensity−duration−frequency (IDF) relationship and nomographs are required for design of soil and water conservation structures. In this study, the rainfall IDF relationships were determined for Shivalik foothills. The raingauge charts of 11 years (2000 to 2010) analysed to get rainfall depth and rainfall intensities for different durations (15, 30, 45 and 60 min). The maximum rainfall intensities for 15, 30, 45 and 60 min duration for 5, 10, 15, 20 and 25 year return periods were found to be 122.5 mm hr−1 to 178.9 mm hr−1 for 15 min, 98.8 mm hr−1 to 151.5 mm hr−1 for 30 min, 87.16 mm hr−1 to 137.4 mm hr−1 for 45 min and 79.7 mm hr−1 to 128.3 mm hr−1 for 60 min duration. The coefficient of determination (R2) varies between 0.90 to 0.95 which showed good relation between maximum rainfall intensity and the return period.