Intensity Duration Frequency (IDF) curve is a mathematical tool used for generating rainfall depth characteristics for various return periods. It is a critical parameter for analyzing extreme events such as floods in urban areas. IDF curves are needed in the planning and design of useful urban drainage structures. The objective of this investigative study is to develop IDF curves for the observed rainfall conditions in the city of Tiruchirappalli, located in the southern state of Tamil Nadu, India. The trends of the intensity, duration and return periods of rainfall are statistically analyzed by Gumbel, Log Pearson Type III, and Log-normal distribution methods for five rain gauge stations situated in the city, from 1976 to 2016 and tested for goodness-of-fit. The Chi-square and Kolmogorov – Smirnov techniques are the goodness-of-fit tests used to determine the best fit. The constant mitigation parameters for the five stations are calculated by the distribution methods, and it is found that the Gumbel distribution method is an appropriate one to predict flood inundation reliably. The rainfall intensities are obtained from this method, and isopluvial maps are generated for different durations and return periods. The results obtained will serve as valuable information for the planning and management of drainage structures in Tiruchirappalli and help avoid future flood disasters.

中文翻译：

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数学关系模型估算蒂鲁吉拉伯利市的减洪参数

强度持续时间频率（IDF）曲线是一种数学工具，用于生成各种返回时段的降雨深度特征。它是分析极端事件（例如城市洪水）的关键参数。在规划和设计有用的城市排水结构时，需要使用IDF曲线。这项调查研究的目的是为印度南部泰米尔纳德邦蒂鲁吉拉伯利市的降雨情况建立IDF曲线。利用Gumbel，Log Pearson Type III和Log正态分布方法对1976年至2016年该市五个雨量计站的降雨强度，持续时间和恢复期的趋势进行了统计分析，并进行了检验的优度适合。卡方检验和Kolmogorov – Smirnov技术是用于确定最佳拟合的拟合优度测试。通过分布方法计算了五个站点的恒定减水参数，发现Gumbel分布方法是可靠地预测洪水泛滥的一种合适方法。通过这种方法可以获得降雨强度，并生成了不同持续时间和返回期的等雨图。获得的结果将为Tiruchirappalli排水结构的规划和管理提供有价值的信息，并有助于避免将来发生洪水灾害。研究发现，Gumbel分布方法是可靠地预测洪水泛滥的一种合适方法。通过这种方法可以获得降雨强度，并生成了不同持续时间和返回期的等雨图。获得的结果将为Tiruchirappalli排水结构的规划和管理提供有价值的信息，并有助于避免将来发生洪水灾害。研究发现，Gumbel分布方法是可靠地预测洪水泛滥的一种合适方法。通过这种方法可以获得降雨强度，并生成了不同持续时间和返回期的等雨图。获得的结果将为Tiruchirappalli排水结构的规划和管理提供有价值的信息，并有助于避免将来发生洪水灾害。