Climate change presents a significant challenge for densely populated estuarine regions with high economic activity. To comprehend the impacts of global warming on hydrology and water resources, a multidisciplinary approach is essential. Weather and climate modelling require expertise not only in atmospheric science but also in applied mathematics and computer science. Numerical modelling is vital in complex scientific fields, ensuring accurate results when analytical solutions are impractical. Understanding the numerical techniques used in models is crucial for researchers to have confidence in the fidelity of their outcomes to the underlying equations.