International Journal of Agriculture, Environment and Biotechnology
Citation: IJAEB: 8(1): 37-48 March 2015
DOI Number: 10.5958/2230-732X.2015.00005.4
©2015 New Delhi Publishers. All rights reserved
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Temporal variation of rainfall trends in parambikulam aliyar
sub basin, Tamil Nadu
R. Vinoth Kumar 1 * and I. Muthuchamy 2
1,2 *Tamil Nadu Agricultural University, Department of Soil and Water Conservation Engineering, Agricultural Engineering College and
Research Institute, Coimbatore – 641 003, Tamil Nadu, India.
*Corresponding author:
Paper No. 289
Received: 18 November 2014
Accepted: 10 February 2014
Published: 24 April 2015
Identification of temporal variation of rainfall trends provides useful information for sustainable
planning and management of water resources in a river basin particularly during flood and drought
periods. The present study was conducted to determine trends in the annual and seasonal total rainfall
over Parambikulam Aliyar sub basin of Tamil Nadu using 30 years (1982-2012) monthly rainfall data at
eight rain-gauge stations. The procedure is based on the nonparametric Mann-Kendall test for the trend
and the nonparametric Sen’s method for the magnitude of the trend. The maximum increase in rainfall
was found at Chinnakallar with an annual rainfall of 90.51 mm/year and the maximum reduction in
rainfall of -8.60 mm/year was found at Topslip during South West monsoon. Significant positive trend
were observed at Weaverly station during North East monsoon rainfall series and significant negative
trend has been noticed in the South West monsoon of Topslip.
  • Positive trends were observed in most of the rain-gauge stations for all rainfall series except South
  • West monsoon season.
  • Rainfall trends determined by Mann-Kendall test reflected in the linear regression analysis.
  • Keywords: Rainfall trend, Mann-Kendall test, Sen’s slope estimator, Regression.
    Climate change is one of the most significant
    governs the crop yield and determine the choice of
    consequences of global warming due to an increase
    the crops that can be grown. The analysis of rainfall
    in greenhouse gases, which is likely to have a major
    for agricultural purpose should include information
    impact on the hydrological cycle and consequently
    concerning the trends or changes of precipitation.
    affecting water resources, flood and drought
    Various researches have been conducted around the
    frequencies, natural and man-made ecosystem,
    world to assess the present trends of rainfall due to
    society and economy (Evans 1997). Crop production
    adverse effect of climate change (Parta and Kahya.
    is largely determined by climatic and soil factors.
    2006, Jayawardene et al. , 2008, Obot et al. , 2010,
    Agriculture and several other economic activities
    Kumar and Jain. 2010, Olofintoye and Adeyemo.
    in tropical to dry areas (Shinde et al. , 2012) depend
    2011). Detailed knowledge of variations in rainfall
    on rainfall. The pattern and amount of rainfall are
    is essential for proper water management practices.
    the most important factors that affect agricultural
    Understanding the variations in rainfall both
    systems. Rainfall is the limiting factors which