Trend analysis and changepoint detection of monthly, seasonal and annual climatic parameters in the Garo Hills of Northeast India

Abstract

This study seeks to identify the change points, tendencies, and trends in climatic parameters and to investigate their relationship with forest cover loss and carbon dioxide (CO2) emission in the Garo Hills region of Northeast India.This study is based on secondary data on Precipitation, Maximum Temperature, Minimum Temperature, Relative Humidity, Tree cover loss, and CO2 emission in Garo Hills from 1984 to 2019. Mann-Kendall's and Sen's slopes were employed to calculate the trend of monthly and seasonal climatic parameters, and Pettitt's test was used to estimate the breakpoints.We further attempted to identify the relationship between the variables under consideration using Pearson's correlation and regression analysis. The results indicate that precipitation levels were generally decreasing over the majority of months and seasons.The maximum temperature showed a marked increase, while the minimum temperature experienced a decrease in all seasons after 2008. From 1999 onwards, the relative humidity has been on the rise in all seasons except monsoon. Regression analysis reveals that the relative humidity and maximum temperature contributed negatively to precipitation. The maximum temperature was positively correlated with both forest cover loss (r = +0.58) and CO2 emission (r = +0.59), while the minimum temperature was negatively correlated with both (r = −0.59 and r = −0.59). This study will provide stakeholders with an understanding of how weather factors vary over time, how forest cover loss and CO2 emissions affect weather patterns in the region, and how to develop climate mitigation strategies.