资源环境科技发展态势分析平台

We analyzed 113years (1901-2013) of daily rainfall over India to investigate spatiotemporal variability of rainfall seasonality. Rainfall seasonality and mean annual rainfall were found to be high over the Western Ghats, central, and northeastern parts of India and over the Indo-Gangetic plains, and low over northwest, southern, and northernmost parts of India. Significant decreasing trends in seasonality coupled with decreasing rainfall were found over parts of central India, the Indo-Gangetic plains, and parts of Western Ghats. Trends in timing of peak rainfall indicate later occurrence in the season, especially over southern Indo-Gangetic plains, by similar to 10-20days per century. In addition, there is a general decrease in the wet-season duration throughout India by similar to 10-20days per century. El Nino-Southern Oscillation and Indian Ocean sea surface temperatures were found to strongly influence seasonality and rainfall over large parts of India. The changes to rainfall and its seasonality will have profound socioeconomic implications for India.

Plain Language Summary Daily rainfall data based on ground-based observations over India has been analyzed for the period 1901-2013 to investigate rainfall seasonality. Rainfall seasonality is found to be high over some parts of India and low over others. Analysis of trends in seasonality and total annual rainfall in the last 113years reveal that there has been a significant decreasing trend in both over parts of central India, the Indo-Gangetic plains, and parts of Western Ghats. The timing of peak rainfall shows a tendency for later occurrence in the season, especially over southern Indo-Gangetic plains, by similar to 10-20days per century. There is also a general decrease in the wet-season duration throughout India by similar to 10-20days per century. El Nino-Southern Oscillations and sea surface temperatures over the Indian Ocean were found to strongly influence seasonality and rainfall over large parts of India. The changes to rainfall and its seasonality can potentially have significant socioeconomic implications for India.