Comparative study of innovative trend analysis technique with Mann-Kendall tests for extreme rainfall

Changes in extreme rainfall have significant effects on the hydrological cycle, and the knowledge about these changes is considerable in planning flood mitigation activities and water resources management. Monthly, seasonal and annual maximum rainfall trends were analysed in this study, using the Mann-Kendall (MK1), modified Mann-Kendall(MK2) trend tests and innovative trend analysis (ITA) technique. Rainfall data were collected from the Indian Meteorological Department (IMD) from 1961 to 2018 for Kondaveeti Vagu, where the proposed legislative capital city of Andhra-Pradesh is located. Variations in trends for seasonal and annual maximum rainfall across Kondaveeti Vagu were analysed with MK1 and MK2 tests and compared with the ITA technique. Using the ITA technique, monotonic and non-monotonic trends are identified in data with or without any condition of the serial correlation, size of the dataset and distributions. Results conclude that rainfall trends showed variability from ITA technique to MK tests. For monsoon season, no trend was detected in MK1 and MK2 whereas the ITA technique detected trends. During the post-monsoon season, trends were seen for all grid points using MK1, MK2 and ITA techniques. The result obtained from the ITA technique agreed with the result obtained from MK1 and MK2 tests. It is also observed that the ITA technique detect trend better than the MK tests. © 2021, Saudi Society for Geosciences.