Detection of Climate Non Stationarity of Indian Rainfall Using Innovative Trend Family of Techniques

The hydrological cycle is significantly impacted by climatic changes, and understanding such changes using statistical or graphical methods is essential for proper management of water resources. This study performs the applications of two most recently proposed variants of popular Sen’s Innovative Trend Analysis (ITA) methods namely Innovative Polygonal Trend Analysis (IPTA) and Innovative Trend Pivot Analysis (ITPA) for analysing the temporal trend of rainfall data of India. The rainfall data of All India along with five Homogeneous regions spanning from 1871–2016, are considered for this study. In order to determine the transition of changes throughout months and seasons, the trend length and trend slope were computed, which explicitly demonstrated a climatic shift in the rainfall of the Indian main land. The IPT and ITP analyses were carried out on both arithmetic mean (AM) and standard deviation (SD) based frameworks and SD of the data is found to be more decisive for monthly and seasonal rainfall over Indian regions in inducing climate non stationarity. The Central Northeast and North East regions show vulnerability to changing climate in rainfall magnitude and variability, while North West and West Central regions brings more risk as captured by ITPA method.