Trend analysis of rainfall and temperature of Ranganadi catchment with a study of the riverline shifts using satellite imagery

Abstract

AbstractA study of trend analysis of rainfall and temperature was carried out in Ranganadi catchment which originates in the hills of Arunachal Pradesh. A nonparametric test (Mann–Kendall and Sen slope test) was employed to check the trend of both rainfall and temperature in different seasons of the year from for a period of 30 years (1990–2021). The test was applied to four stations, namely, Itanagar, Chyang Tajo, Lilabari, and NH Road Crossing covering the catchment area of Ranganadi. The test revealed a nonsignificant trend of rainfall and somewhat significant trend for temperature. The study further focused to analyze the shift and sinuosity index of the river for the years (1999–2020) with an interval of 3 years using satellite images. While the sinuosity index test failed to establish a significant change of category of the river, there were significant changes of bankline shifts, which were noticed in the same period of analysis more of random in nature. The shifting of the river added to significant social and economic problems in the study area including unemployment and population migration. It opens for a study of this temperature change to be investigated with these erratic shifts for a further analysis. This study aimed to investigate several key aspects in the floodplain of the Subansiri–Ranganadi Doab, Brahmaputra Valley, India. The research encompassed a comprehensive analysis of rainfall and temperature trends in the Ranganadi catchment area, originating from the hills of Arunachal Pradesh.