Trend Analysis of Rainfall and Temperature of Patiala City

Abstract

The temperature and rainfall are the most dominant variable of hydrological and weather studies. Any change in these variables will affect the water demand, stream flow and hydrological cycle. This study mainly focuses on detecting trends in temperature and rainfall for the Patiala city, Punjab. For this study, Mann-Kendall test is used at 5% significance level and quantified with Sen slope estimator test for the time period 1998 to 2015. The statistical analysis using box and whisker plots are also made to study the uniformity of the data. Furthermore, a correlation between the rainfall and average temperature is found out using Pearson correlation, Kendall Tau and Spearman rank correlation test. The results of Mann-Kendall test revealed that in the monthly analysis, decreasing significant trends of average temperature is found for the month of April at 0.13°C per year and an increasing significant trend of minimum temperature is seen for November month with 0.37°C per year. For the seasonal analysis, positive significant trends are seen for the average temperature in the southwest monsoon and the post monsoon season. Also increasing significant trends of maximum temperature is seen for the winter season. In the annual analysis, significant increasing trend is seen for the minimum temperature. The present study did not find any significant trend for rainfall. The present study established the correlation between rainfall and average temperature. It is found that in the monthly analysis, significant correlations exists for the March, June, July and August months at 0.01 and 0.05 significance level. Also it is found that post monsoon season is significant for the seasonally correlation between rainfall and average temperature.