Recent Rainfall Trend and Drought Behavioural Assessment in the Pantnagar Region of Uttarakhand

摘要

The present study is carried out to investigate the long-term variation and distribution of rainfall at monthly, seasonal and annual time scale for the last 48 years (1970—2017) in the Pantnagar region of Uttarakhand state. The daily rainfall data from January, 1970 to October, 2017 were collected from meteorological observatory of G. B. Pant University of Agriculture and Technology, Pantnagar. The commonly used non-parametric Mann-Kendall (MK) test was employed to identify the trends; and the Sen'sslope estimator was applied to detect the magnitude of rainfall time series trend. The drought behavioural assessment was carried out using the two different drought indices viz. Standard precipitation index (SPI) and Rainfall departure (RD). In the study region, the maximum and minimum rainfall values of annual data series were respectively 3218.6 mm and 831.2 mm. The rainy season rainfall was found to vary from 59.51 to 96.27 % of the total annual rainfall. No significant (at 5% level) monthly, annual and monsoon season rainfall trend could be found in the study region. However, both annual and rainy season data analysis showed a non-significant incremental trend. The drought analysis through SPI shows that the months of October, November and December had never suffered any kind of drought. The results from SPI analysis show that extreme and exceptional drought rarely occurs in the Pantnagar region. Similar to SPI, the RD method also showed that most of the years exhibited no drought. Notably, therainy season of the year 2017 was not under any kind of drought.