Trend analysis of annual and seasonal rainfall to climate variability in North-East region of India

Abstract

Global warming, climate change and its consequences are major threat for the global agriculture. The agriculture in the North-East region of India is supposed to more in danger due to its topographic features. Agriculture in the state of Arunachal Pradesh is dependent on rainfall and variability in rainfall due to climate change is expected to threaten the food production in future. This study examines the impact of climate change on rainfall using the trend analysis technique for the four districts of Arunachal Pradesh. For this purpose temporal trends in annual and seasonal rainfall were detected using nonparametric Mann-Kendall test at 5% significance level. The daily time series rainfall data for the period 1971-2007 were analyzed statistically for each district separately. The results of Mann Kendall test showed decreasing trend in annual mean rainfall in east Siang, upper Siang and lowers Dibang valley and no trend in the west Siang district over the period of 1971-2007. In case of east Siang, upper Siang and lower Dibang valley districts, decreasing trend of rainfall was observed in the post monsoon season with slope magnitude of 3.01 mm/yr, 3.32 mm/yr and 3.95 mm/yr respectively. Decreasing pattern of rainfall in post monsoon season may affect the vegetable and fruit production in the winter season.