4.1 Lost water

To determine the extent of water loss in the watershed, we first calculated the exact amount of this loss by analyzing the factors that displayed trend, inter-basin water transfer tunnel, and aquifer storage volume. The annual excess water volume of the Cheshmeh-Langan tunnel was determined by removing the trend from the tunnel's discharge data. The tunnel's discharge and trend-free data and Annual excess water volume (MCM) are shown in Figure \ref{407510} and Table \ref{974045}, respectively.