Climate change and spatio-temporal trend analysis of climate extremes in the homogeneous climatic zones of Pakistan during 1962-2019

Fig 12 shows decreasing trend in precipitation extremes except CDD and WSDI in western and eastern parts. However, CWD, R10mm, R20mm, R25mm, R95 have increasing trends while CWD and PRECPTOT show decreasing trends in the eastern-central Karakoram. 5. Discussion Zone 1 is rich with water resources (snow and glaciers). Therefore, the changes in climate and climate extremes may have significant impacts on water availability in dry summers, the fre- quency of flooding, and Glacier Lake Outburst Floods (GLOFs) in the future. Zone 2 comprise Monsoon dominated region receiving more than 60% precipitation during Monsoon season [77–79]. The seasonal changes in precipitation and temperature may affect the demand and supply of water and ultimately the crop’s production. In addition, Zone 3 is the south-west part of Pakistan receiving low amount of rainfall round the year. Precipitation extremes may contribute less to cause flooding in the region. Zone 4 faces shortage of rainfall and have severe rainfall decrease, which can further exacerbate the shortage of water for drinking, agriculture and other purposes. Zone 5 is mainly comprised of Punjab province dominating the agricul- ture production of the country. According to our results, R99P has increasing trend in this region with the likelihood of intense rainfall and may cause flash flooding in the future. As UIB is melt water dominated, therefore, the latest information of the cryosphere is important. In addition, changes in climate variables can significantly affect downstream

Table 6. Seasonal MK test results in the Karakoram region for precipitation. The table shows the Kendall τ and their significance for the 1990–1999, 2000–2009 and 2010–2019. Station DJF MAM JJA SON Station Kendall τ P-Value Kendall τ P-Value Kendall τ P-Value Kendall τ P-Value Precipitation (1990–1999) Astore -6.75e-02 0.007 -1.06e-02 0.663 -2.46e-02 0.327 -2.40e-02 0.357 Bunji 4.34e-02 0.104 8.94e-02 0.000 4.04e-02 0.121 4.50e-02 0.091 Chilas 4.21e-02 0.114 4.48e-03 0.862 1.66e-02 0.524 1.16e-03 0.965 Darosh -9.16e-0 0.000 -3.57e-02 0.140 2.14e-03 0.934 9.95e-03 0.702 Gilgit 2.46e-02 0.351 2.67e-02 0.289 6.03e-02 0.018 -1.62e-02 0.539 Gopis -1.62e-03 0.951 4.77e-02 0.069 6.50e-02 0.014 -6.71e-02 0.012 Skardu -3.37e-02 0.190 3.81e-02 0.133 7.15e-02 0.006 6.41e-02 0.016 Precipitation (2000–2009) Astore -5.21e-02 0.044 -1.02e-01 5.227e-05 -4.62e-02 0.068 -3.80e-02 0.146 Bunji 3.58e-02 0.180 -1.20e-02 0.645 2.65e-02 0.307 -3.15e-02 0.236 Chilas 1.22e-01 4.14e-06 4.03e-02 0.118 1.13e-01 1.52e-05 5.52e-02 0.038 Darosh 6.47e-02 0.011 2.31e-02 0.355 -5.41e-02 0.038 -3.77e-02 0.147 Gilgit 6.84e-02 0.009 1.31e-02 0.608 -3.86e-02 0.127 -2.61e-03 0.921 Gopis 5.69e-02 0.033 -3.12e-02 0.234 -8.10e-02 0.002 -6.50e-02 0.015 Skardu 5.38e-02 0.037 -1.41e-02 0.584 -2.92e-02 0.254 8.34e-04 0.975 Precipitation (2010–2019) Astore -1.30e-01 7.53e-06 1.34e-03 0.961 -6.15e-03 0.828 -3.59e-02 0.219

Bunji -3.37e-03 0.910 -7.70e-03 0.787 -1.60e-02 0.574 -2.59e-02 0.379 Chilas 1.57e-01 9.5e-08 -3.05e-02 0.286 -1.18e-02 0.683 -9.35e-02 0.001 Darosh 6.88e-03 0.812 -1.27e-02 0.646 -1.95e-02 0.502 -4.89e-02 0.095 Gilgit -1.03e-02 0.728 -3.62e-03 0.898 -2.35e-02 0.401 -6.59e-02 0.023 Gopis 4.52e-03 0.881 7.16e-02 0.014 6.73e-03 0.818 -7.48e-03 0.802 Skardu -1.54e-01 1.98e-07 1.26e-02 0.66 4.69e-02 0.102 -2.52e-02 0.395 https://doi.org/10.1371/journal.pone.0271626.t006 PLOS ONE Climate change and extremes analysis using observed data (1962-2019) over Pakistan PLOS ONE | https://doi.org/10.1371/journal.pone.0271626 July 27, 2022 18 / 27