Trend in Observed and Projected Maximum and Minimum Temperature over N-W Himalayan Basin

Recently, study in past trends of climate variables gained significant consideration because of its contribution in adaptions and mitigation strategies for potential future changes in climate, primarily in the area of water resource management. Future inter-annual and inter-seasonal variations in maximum and minimum temperature may bring significant changes in hydrological systems and affect regional water resources. The present study has been performed to observe past (1970-2010) as well as future (2011-2100) spatial and temporal variability in temperature (maximum and minimum) over selected stations of Sutlej basin located in North-Western Himalayan region in India. The generation of future time series of temperature data at different stations is done using statistical downscaling technique. The non-parametric test methods, modified Mann-Kendall test and Cumulative Sum chart are used for detecting monotonic trend and sequential shift in time series of maximum and minimum temperature. Sen's slope estimator test is used to detect the magnitude of change over a period of time on annual and seasonal basis. The cooling experienced in annual T_Max and T_Min at Kasol in past (1970-2010) would be replaced by warming in future as increasing trends are detected in T_Max during 2020s and 2050s and in T_Min during 2020s, 2050s and 2080s under A1B and A2 scenarios. Similar results of warming are also predicted at Sunni for annual T_Min in future under both scenarios which witnessed cooling during 1970-2010. The rise in T_Min at Rampur is predicted to be continued in future as increasing trends are obtained under both the scenarios. Seasonal trend analysis reveals large variability in trends of T_Max and T_Min over these stations for the future periods.