Changes in rainfall affect drinking water, river and surface runoff, soil moisture, groundwater reserve, electricity generation, agriculture production and ultimately the economy of a country. Trends in rainfall, therefore, are important for examining the impact of climate change on water resources for its planning and management. Here, as analysed from 119 years of rainfall measurements at 16 different rain gauge stations across northeast India, a significant change in the rainfall pattern is evident after the year 1973, with a decreasing trend in rainfall of about 0.42 0.024 mm dec⁻¹. The wettest place of the world has shifted from Cherrapunji (CHE) to Mawsynram (MAW) (separated by 15 km) in recent decades, consistent with long-term rainfall changes in the region. The annual mean accumulated rainfall was about 12 550 mm at MAW and 11 963 mm at CHE for the period 1989–2010, as deduced from the available measurements at MAW. The changes in the Indian Ocean temperature have a profound effect on the rainfall in the region, and the contribution from the Arabian Sea temperature and moisture is remarkable in this respect, as analysed with a multivariate regression procedure for the period 1973–2019. The changes in land cover are another important aspect of this shift in rainfall pattern, as we find a noticeable reduction in vegetation area in northeast India in the past two decades, implying the human influence on recent climate change.

降雨的变化会影响饮用水，河流和地表径流，土壤湿度，地下水储备，发电，农业生产以及最终影响一个国家的经济。因此，降雨趋势对于检查气候变化对其水资源的规划和管理影响至关重要。根据印度东北16个不同雨量计站119年的降雨测量结果进行分析，1973年以后，降雨格局发生了明显变化，降雨量下降趋势约为0.42 0.024 mm dec ^-1。最近几十年来，世界上最潮湿的地方已经从Cherrapunji（CHE）转移到Mawsynram（MAW）（相距15 km），与该地区的长期降雨变化一致。从MAW的可用测量结果推算，1989-2010年期间，MAW的年平均累积降雨量约为12550 mm，CHE的年平均降雨量约为11963 mm。印度洋温度的变化对该地区的降雨产生了深远的影响，阿拉伯海的温度和湿度在这方面的贡献是显着的，这是通过1973-2019年期间的多元回归程序进行分析的。土地覆盖的变化是这种降雨方式转变的另一个重要方面，因为我们发现过去二十年来印度东北部的植被面积明显减少，