Analysis of meteorological parameter changes using Mann-Kendall statistical tests in Indian Punjab

Groundwater in Central Punjab is declining at an alarming rate of one meter annually in last two decades and likely to be exhausted up to 300 meter depth in next 2-3 decades as per recent report published in 2018 based upon exhaustive analysis done till 2017 by the relevant agencies (Anonymous, 2018). All the blocks in this zone are over exploited. Rainfall and temperature are predominant meteorological parameters which influence irrigation demand which in turn influences ground water withdrawal; which ultimately influence groundwater depth in the region. Area under rice is increasing due to high returns. So, the trend analysis of these parameters is of paramount importance for sustainability of agriculture in this region. The aim of the present investigation was to study annual trend of precipitation, maximum and minimum temperature and rainfall for 10 locations in Central Punjab during 1998–2019. The effect of rainfall and rice area on groundwater depth has been also studied.  To achieve this non-parametric Mann-Kendall and Sen's applied to the data series of annual rainfalls, annual maximum and minimum temperature of the ten selected stations. The nonparametric statistical tests applied to series of annual Tmax revealed an increasing trend in all of the locations of the study area. According to results by Sen’s slope estimator, the increasing trend in annual precipitation series was detected at the Tarantaran, Kapurthala,Ludhiana, Moga, Barnala and Jalandhar, while other stations had negative or no trends.