Extreme value analysis of meteorological elements at Trombay, Mumbai

摘要

Extreme value analysis of meteorological elements at Trombay is presented in this paper. The elements analysed are annual rainfall, maximum monthly rainfall, maximum daily rainfall, maximum and minimum air temperature, minimum relative humidity and maximum wind speed. The observation period for the rainfall data is 1959-1996, while for the others the period is 1985-1997. It is found that all the elements except maximum daily rainfall obeyed Fisher-Tippett Type I distribution, while the maximum daily rainfall followed Fisher- Tippett Type II distribution which has been attributed to its bi-modal frequency distribution. Parameters of the distribution functions for Each element are established. Extreme values corresponding to return periods of 50 and 100 years are derived. Extreme values Corresponding to typical 50 years return period at Trombay are compared with corresponding values at other three nuclear reactor sites in India, namely, Tarapur, Kota and Kalpakkam obtained in an earlier study. In addition, the extreme value analysis of the concurrent Rainfall data collected at two more locations within the Mumbai city, viz. Colaba and Santacruz, both within 15-20 kilometres from the Trombay location, is also carried out and the location-wise differences between the parameters of the distribution functions are discussed.