MODELLING RAINFALL VARIABILITY, TREND AND ANOMALY IN JHELUM RIVER BASIN, WESTERN HIMALAYA

This paper aims to analyze rainfall patterns and its trend in the Jhelum River Basin to determine the possible effects of climate change. The Jhelum River Basin lies in the Western Himalayas. These analyses were executed using rainfall data of the selected meteorological sites, i.e. Jhelum, Kotli, Murree, Muzaffarabad and Rawalakot meteorological stations. Alongside, the necessary statistical analysis was accomplished by using Addinsoft excel states i.e. ARIMA model. This research study focuses on rainfall trend detection and anomalies prediction. The analysis of temporal data for the period 1993-2022 demonstrated an increase in the annual rainfall variability, the shift toward more frequent extreme years both in terms of rainfall and drought conditions. The relative linear regression coefficient reveals that stations such as Kotli, Rawalakot and Murree had greater fluctuation showing increased unpredictability in the rainfall pattern, however more stable regions like Jhelum had lower variations. This implies that with increase in altitude or with variation in climates can be observed in the meteorological station of Murree. Using ARIMA model, the analysis express that the met station of Jhelum received greater quantity of rain such 1335 mm and 1232 mm respectively during the years 1997 and 2006. Similarly, the years-2009 and 2002 had a les amount of rain such as 543 and 532 mm showing comparatively greater variability. The anomalies were computed for Jhelum basin reveal the deviation of rainfall in all the met stations. Additionally, Kotli recorded the highest amount of rainfall i.e. 1504 mm during the year-1994. Likewise, Murree has great flux has been noted i.e. the years 2004 and 2015 confirmed relatively high annual rainfall i.e. 2417 mm and 2307 mm respectively. Moreover, Balakot station received comparatively greater total annual rain in 2004 i.e. 2316 mm. In case of Garhi Dupatta, great fluctuation was observed such as 1812 mm of rain in 1994. In terms of Rawalakot station during the period 2004-2022, there were noted high and low rainy spell. This research will help enhance knowledge on how climate change is impacting precipitation regimes in the Western Himalayas.