Trend and variability of hourly intensity of rainfall over eastern and northern part of Uttar Pradesh during 1969-2014

Abstract

It is now widely accepted question that average value of the world temperature has gone up because of climatologically significant emission of greenhouse gases by means of anthropogenic sources. Global warming may be witnessed by changes in the frequency of occurrence of the extreme weather events such as severe floods, storms and drought. The topic of climate change is being discussed on international platforms. With this reference reports of Intergovernmental panel on climate change (IPCC) are important. In this era of climate change and global warming, we set the objective of this study to find out the trend and intensity of rainfall in the selected four stations, viz., Barielly, Lucknow, Allahabad and Bapatpur (Varanasi Airport) of Uttar Pradesh (UP), India based on hourly rainfall data. These stations are selected on better data availability and to represent eastern and northern part of UP. Firstly hourly rainfall data of all four stations ranging from 1969 to 2014 is examined. The percentile of hourly data is calculated to define various intensities of hourly rainfall of the stations. Based on different percentiles groups, intensity of the rainfall is classified into very light spell, light spell, moderate spell, intense spell, very intense spell, extremely intense spell, exceptionally intense spell. For each percentile group, yearly, monthly, JJAS (monsoon) frequency distribution is prepared. Frequency distribution trend is analyzed by means of t-test, p-value, slope and R square. Statistical significance of the trend is done by t-test. It is found that the rainfall of different intensities in yearly, monthly, JJAS (monsoon) for all the four stations is not statistically significant. From this it may be infer that even in the era of climate change, the trend and intensity of hourly rainfall in the eastern and northern parts of UP is not changed.