Nature Environment and Pollution Technology

Anu Varughese ¹, M. S. Hajilal ¹, B. A. George ²

Affiliations
1 Department of Irrigation and Drainage Engineering, Kelappaji College of Agricultural Engineering and Technology, Kerala Agricultural University, Tavanur-679573, Kerala, IN
2 International Centre for Agricultural Research in the Dry Areas, Cairo, EG

Abstract

Climate change is considered as a global phenomenon, but investigations at the regional level are essential to understand the changes induced, and to suggest suitable adaptation strategies. This study is mainly concerned with the variation of temperature and rainfall in a river basin which lies in the tropical climate of India. Observed temperature and rainfall data were compared with the gridded data prepared by the Indian Meteorological Department (IMD) and was found comparable. The trend analysis of mean, maximum and minimum temperatures during 1951-2013 showed a significant warming trend with Mann-Kendall test statistic values of 4.63, 5.52 and 3.63 respectively. The increase in mean, maximum and minimum temperatures during the period were at the rate of 0.07°C/decade, 0.14°C/ decade and 0.04°C/decade respectively. Trend analysis of the gridded rainfall data for the period 1971-2005 showed statistically significant decreasing trend, at the rate of 15 mm/year. Mann-Kendall and t-test gave a statistical significance at a level of a=0.1 and a=0.05 respectively. Trend analysis of seasonal rainfall indicated that there was no significant trend in rainfall except during the south-west monsoon period. Appropriate mitigation measures need to be undertaken for controlling the future scarcity of water considering the increasing temperature trends and decreasing rainfall pattern.

Keywords

Mann-Kendall Test, Trend Analysis, Bharathapuzha, Climate Change.

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