Centennial Scale Trend Analysis of Summer Monsoon Rainfall in Hot and Arid Agro-Ecological Region of North Western India

The rainfall is one of the controlling factor to determine the climatic conditions of a region. Further rainfall in India is mainly associated with summer monsoon and particularly in arid or semi-arid region of north west India where any significant variation in rainfall trends drives subsequent adverse impact on the socio-economic conditions of the society. The study has been carried out centennial scale (1901–2021) trend analysis of summer monsoon rainfall in hot and arid Agro-ecological region of North western India. It mainly occupies Kutch district of Gujarat, western region of Rajasthan and south-western region of Haryana and Punjab. The IMD gridded data (0.25° × 0.25°) is taken and further specifically grouped into summer months of June, July, August and September at district level and Climate Hazards Group InfraRed Precipitation with Station data (CHIRPS) of 0.05° resolution (19812021) is taken for the same months to obtain the monthly trend. Further, synchronization is done with the growing and ripening period of kharif crops to comprehend the responses could be of the intraseasonal variability. The Mann-Kendall and Pettitt Test has been used to assess the long term time series trend and to further assess the changing threshold point or year respectively. Findings from IMD data show that there is significant positive trend in the month of June in almost all districts and also similar trend is shown by CHIRPS data that would be beneficial for the crops as it is the month of sowing crops. The year of change in rainfall is around 1970s and 80s in month of June. But CHIRPS data also indicate significant positive trend in the month of September which is not present in IMD data that is because of high resolution and recent data. Thus, the results of this study can be used to develop adaptive steps to make the society resilient to the change of climatic factors especially for this region which is not much developed in terms of industry and service sector.