Non-Parametric Trend Analysis in South-East Regions of Uttarakhand, India

  • Shekhar Singh
  • Sonali Kumara
Keywords: Trend analysis, Moving average, Mann Kendall test, Rainfall estimation, Almora


Rainfall estimation plays a vital role in planning irrigation schedule and managing discharge through small or big dams. In the last few years, the total rainfall has been observed to be concentrated only in few rainy days. The consequence of it may be in the form of flood or stability issues on the hydraulic structures. Thus, it is important to study the spread of total rainfall in a year. In the present study, the number of rainy days for Almora district of Uttarakhand has been used. The temporal data between 1987 to 2011 was collected from India Water portal. Statistical trend detection for the data was dome using Moving Average Models, Linear Regression Models and Mann Kendall Test. In this study, trend detection has been done for all the twelve months for the said time series. Moreover, trend detection was performed for annual average rainy days for mentioned said time series. The results showed that the months of February, March, November and December, the number of rainy days showed a decreasing trend, while for the months of January, April, May, June, August, September and October showed an increasing trend. The month of July for the said time series showed no trend. Further, annual rainy days showed no significant trend. Thus, in the said time series, annually seven months had shown an increasing trend, while four months has shown decreasing trend in rainy days.



Caloiero, T., Coscarelli, R., Ferrari, E., Mancini, M., 2011. Trend detection of annual and seasonal rainfall in Calabria (Southern Italy). International Journal of Climatology 31 (1), 44-56.

Jhajharia, D., Yadav, B. K., Maske, S., Chattopadhyay, S., Kar, A.K., 2012. Identification of trends in rainfall, rainy days and 24 h maximum rainfall over subtropical Assam in Northeast India. Comptes Rendus Geoscience 344 (1), 1-13.

IWP, 2021. Indian Water Portal (IWP). Available at: Kumar, V., Jain, S.K., 2010. Trends in seasonal and annual rainfall and rainy days in Kashmir Valley in the last century. Quaternary International 212 (1), 64-69.

Mann, H.B., 1945. Nonparametric tests against trend. Econometrica: Journal of the Econometric Society 13 (3), 245-259.

Kendall, M.G., 1975. Rank correlation methods. London: Charles Griffin, 35.

Modarres, R., da Silva, V.D.P.R., 2007. Rainfall trends in arid and semi-arid regions of Iran. Journal of Arid Environments 70 (2), 344-355.

Partal, T., Kahya, E., 2006. Trend analysis in Turkish precipitation data. Hydrological Processes 20 (9), 2011-2026.

Parthasarathy, B., Dhar, O.N., 1975. Trend analysis of annual Indian rainfall. Hydrological Sciences - Bulletin 20 (2), 257-260.

Pujol, N., Neppel, L.U.C., Sabatier, R., 2007. Regional tests for trend detection in maximum precipitation series in the French Mediterranean region. Hydrological Sciences Journal 52 (5), 956-973.