Trend analysis by Mann-Kendall test for precipitation and temperature for thirteen districts of Uttarakhand

Abstract

The present study is mainly concerned with the changing trends of rainfall and temperature of all the thirteen districts of the state Uttarakhand. The state lies on the southern slope of the Himalayan range and the climate and vegetation vary greatly with elevation, from the glaciers at the highest elevations to subtropical forests at lower elevations. In the present study, we have tried to analyze the most important climatic variables precipitation and temperature, for analyzing the trend in the area. For this, daily rainfall data of 41 years from 1971 to 2011 and minimum and maximum temperature data of 37 years from 1971 to 2007 has been processed in the study to find out the monthly variability of rainfall and temperature for which Mann-Kendall (MK) Test has been used together with the Sen’s Slope Estimator for the determination of trend and slope magnitude. Monthly precipitation and temperature trend has been identified here to achieve the objective which has been shown by 41and 37 years of data. There are increasing trends of precipitation and temperature in some months and decreasing trends in some other months for all the thirteen districts of Uttarakhand obtained from these statistical tests suggesting overall insignificant changes in the area.

Keywords

• Rainfall
• Trends
• Mann-Kendall trend test
• Sen’s Slope estimator