SPATIOTEMPORAL RAINFALL VARIABILITY IN HUMID SUBTROPICAL ZONE, INDIA

Abstract

Climate change is profoundly altering rainfall patterns in India, resulting in a surge in extreme weather events, including floods, droughts, and landslides. Unpredictable monsoon seasons feature intense, localized downpours that overwhelm drainage systems and prolonged dry spells that aggravate drought conditions. The humid subtropical zone, as classified in the Koppen climate classification system, is the study area. The humid subtropical regions in India are greatly influenced by the seasonal monsoon rains. The agricultural and water resource systems are directly dependent on rain for sustenance. This study is based on the short-term rainfall variability using a method called the 5-year grouping method. The analysis has been carried out annually and seasonally. The annual maximum rainfall for humid subtropical varies mostly between rather heavy rainfall to extremely heavy rainfall. In January and February, the maximum rainfall for humid subtropical varies between no rain to very heavy rainfall in the study period. In March, April, and May, the maximum rainfall for humid subtropical varies between no rainfall to very heavy rainfall in the study, except in the years 1986 to 1980, where the rainfall is exceptionally heavy. In June, July, August, and September, the maximum rainfall for humid subtropical varies between rather Anila Arelt, Shivakumar J. Nyamathi https://iaeme.com/Home/journal/IJCIET 21 editor@iaeme.com heavy rainfall to extremely heavy rainfall throughout the study period, except in the years 2006 to 2010, where the maximum rainfall is about 650 mm in Bihar. In October, November, and December, the maximum rainfall for humid subtropical varies mostly between no rain to very heavy rain/ extremely heavy rainfall throughout the study period, except in the years 1956-1960 and 1966-1970, where the rainfall exceeds 300 mm. It is generally observed that recent years are witnessing frequent extreme events when compared to earlier years. Decision makers have to take the necessary measures to combat the recent changes in rainfall during planning and design.