Spatial and temporal hydro-climatic trends in the transboundary Jhelum River basin

The present study examined the hydro-meteorological trends and their magnitudes using the MannKendall, Sen's slope, and linear regression methods in the Jhelum River basin. Maximum and minimum temperatures showed increasing trends in the basin. However, the increasing trends of maximum temperature in all seasons as well as in annual datasets were stronger and statistically more significant than minimum temperature. Precipitation showed non-significant increasing and decreasing trends spread evenly throughout the basin. However, decreasing trends dominated in the basin, except in winter, with an average annual decrease of 3.3 mm. In case of streamflow, seasonal and annual decreasing trends dominated in the basin. Summer showed stronger and significant decreasing trends at most of the hydrometric stations in the basin. An annual decrease of 8 mm was observed at Azad Pattan. These decreasing trends are most probably due to decreasing trends in precipitation and increasing trends in temperature, though other factors such as land use changes, industrialization, and urbanization can also affect the changes in streamflow. These decreasing trends in precipitation and stream flow can have some serious implications in the reduction of water availability to the Mangla reservoir, thus producing many challenges for efficient reservoir operation and management.