Redevelopment of Rainfall Intensity Duration Frequency Relationships Using Gumbel and Log Pearson Distributions for Srinagar Region, J&K, India

IDF curves and rainfall equations are crucial tools for the planning, design, and management of water resource projects. This study emphasizes the creation and comparison of rainfall intensity–duration–frequency (IDF) relationships using Gumbel and Log Pearson type III distributions specifically for the Srinagar Station in Jammu and Kashmir, India. Accurate IDF curves are essential for effective hydrological planning and infrastructure design, particularly in regions prone to extreme weather events. By analyzing historical rainfall data, IDF curves were generated for various return periods and durations using both statistical distributions. For this purpose, a dataset comprising 20 years of hourly rainfall data sourced from the ECMWF Web site was utilized. Through screening the data via R Programming, relevant data for various durations up to 18 h was extracted. For the Srinagar station, frequency analysis techniques such as Gumbel and Log Pearson type III methods are employed for analyzing rainfall corresponding to different return periods spanning between 2 and 100 years. Statistical analyses including chi-square, Kolmogorov–Smirnov, and Anderson–Darling tests are conducted for identification of best-fit distribution. This involved comparing calculated values with chi-square critical values to determine the most appropriate statistical distribution, whether Gumbel or Log Pearson type III. The derived intensity equations were then compared with existing equations to assess improvements and discrepancies. Results indicate that the Gumbel distribution generally fits best for rainfall intensities compared to the Log Pearson distribution. This comparative analysis enhances our understanding of rainfall patterns in this region and provides a more reliable foundation for managing water resources and mitigating flood risks.