Study the Temporal Variability of Climate Change in Urban City Karachi, Pakistan
DOI:
https://doi.org/10.70917/jcc-2025-033Keywords:
trend detection, Mann-kindle test, Sen’s slope estimator, temperature; rainfallAbstract
Climate change particularly changes in temperature and rainfall patterns have serious long-term influences, mainly caused by human actions. It can leads to severe events like heat-waves, floods, increasing seas, and more extreme weather, which in turn affects across various aspects of socioeconomic factors, ecosystems, hydrology, health, and global warming. Temperature and rainfall are essential climatological variables that are being comprehensively studied across the Karachi city to understand and manage their dynamic nature. The objective of this study is to analyze the trend, magnitude, and change points in climatic variables to investigate their variability in the urban city Karachi. Rainfall and temperature datasets for the Karachi station from 1980 to 2020 was used. Monthly and annual precipitation as well as temperature (maximum, and minimum) was analyzed for possible trends using nonparametric Mann-Kendall (MK) test, while the Sen’s slope (SS) estimator was used for magnitude of a trend. The Pettitt’s test was applied to detect the abrupt change point in climatic variables. The results revealed increasing trend in annual and monthly maximum temperatures while for minimum temperature all the months illustrated significant increasing trend in the study period. The SS estimator revealed that the annual temperature increased with rate of 0.025 °C per year for the certain time interval. However, in contrast to variation in the temperature trend, the mean annual rainfall of the study period was observed 180.4 mm with no significant increasing trend while 366.8 mm rainfall was observed in the month of the August 2020. The only month of the February has statistically significant decreasing trend with rate of change of 0.097mm/year and no significant trends was present for all other months. This study provides evidence that can aid policy adaptation, and addressing climate change by responding extreme events like floods and heat-waves.
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Copyright (c) 2025 Mrs. Zehra A. Naveed, Bulbul Jan, Syeda Ismat Zehra, Syed Inayatullah (Author)
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