Long-term Trends in Rainfall Pattern over Haryana, India

Abstract

In this study, seasonal and annual trends of changes in rainfall have been studied over the 110 years (1901-2010) for nineteen districts of Haryana. Mann-Kendall test and Sen’s slope estimator was used to detect monotonic trend direction and magnitude of change over time. The annual rainfall varies from 311 mm in the western part (Sirsa district) to 706 mm in the northeast part of Haryana (Yamunanagar district). All the stations except Kurukshetra and Panchkula showed a significant increasing trend in annual rainfall at a significance level of 1%, 5% and 10%. The increase in annual rainfall magnitude varied between 0.53 to 1.5 mm per annum at Sirsa station and Sonipat stations respectively. Seasonally, pre-monsoon rainfall showed significant increasing trends at all the stations and its magnitude varied from 0.07 to 0.20 mm annum^-1. Among nineteen stations, only seven stations indicated significant upward trend in monsoon rainfall. Further, significant increase was found in annual, pre monsoon and monsoon rainfall over entire Haryana during the period of analysis. Further, rainfall correlation with cloud cover and temperature variables (maximum temperature, minimum temperature and diurnal temperature range) demonstrates that rainfall of the Haryana state is more responsive to the variation of temperature on annual, winter and pre-monsoon season. However in monsoon and post-monsoon season cloud cover plays the important role in rainfall variation. The results comparing the monsoon rainfall and SST anomaly leads to the idea that all ENSO events are not associated with drought in study area.