Equation 1
\begin{equation}
\text{PE}_{\text{ij}}\ \left(\%\right)=\ \frac{C_{\text{pred\ ij}}\ -\ C_{\text{obs\ ij}}}{C_{\text{obs\ ij\ }}}\ \times 100\nonumber \\
\end{equation}To evaluate bias (i.e. overestimation or underestimation of
Cpred from the line of unity) of the model predictions,
median prediction error (MDPE) was estimated with Equation 2 :