Spatio-temporal Trend Analysis of Climatic Variables over Jharkhand, India

摘要

Time-series data for climatic variables of Jharkhand state, India were analyzed to assess the spatio-temporal variation and fluctuation over the study period of 118 years (1901-2018). Mann-Kendall (MK), Sequential Mann-Kendall (SQMK), and Sen's slope tests were applied to determine the trend of precipitation, temperature maxima-minima, and Potential Evapotranspiration (PET) time-series data acquired after removal of serial autocorrelation called prewhitening. Minimum and maximum temperature revealed insignificant variation during pre-monsoon and monsoon season, while a remarkable increasing trend was observed for post-monsoon and winter season; however, increasing trend was obtained for annual maxima-minima. The average minimum temperature fluctuates with an increase of 0.59-0.41 oC to a decrease of 0.79-0.39 oC, whereas average maximum temperature fluctuates with an increase of 1-1.5 oC to decrease of 0.82-0.14 oC. Notably, decreasing trend of 1.09-2.3 mm/year was observed for precipitation during monsoon season, whereas decreasing trend of 1.2-2.4 mm/year was found for annual precipitation, and similarly for PET, significant decreasing trend of 0.0003-0.0012 mm/year was found for monsoon season and annually. However, the underlying persistence effect observed in all seasons and throughout the year for all climatic parameters resulted in the time-series with low-frequency fluctuations. SQMK method exhibits the periodic fluctuation of trends, which are more noticeable in pre-monsoon and monsoon season. An understanding of these alterations in pattern of climatic variables is important for planning and management of water resources and sustainable agriculture.