A Review on Hydrological Modelling Concepts: Part 1 - Introduction of Modelling Process

The processes and components of hydrological cycle are very complicated in nature, with significant spatial and temporal variation. This is due to high non-linear and complex relations between hydrological components, economical limitations for accurate measurements, and requiring a variety of data and information. The main solution for understanding and predicting hydrological processes at watersheds scale is using/developing simulation models based on desired goals. However, due to the lack of attentions to the concepts and practical knowledge, development of hydrological models has attracted less attention. By neglecting the modelling process in hydrological modelling, and starting this process directly by choosing a procedural model and its calibration would provide unreliable results. Therefore, it is essential to have a comprehensive and accurate inspection of the modelling process and its application as a useful tool for understanding and analyzing hydrological systems. This paper aims at providing concepts of hydrological modelling and introducing five-steps modelling process for watersheds, and finally presenting information about the various types of hydrological models.