A Brief Review on Hydrological Modelling

The interaction between water, climate, soil and land use is primary to the hydrological modelling concept. Hydrological models include spatial and temporal features. Hydrologists utilize hydrologic models as a primary tool for a variety of tasks including managing water resources, managing urban and rural areas, modelling ground water and more. In order to implement hydrologic models with ease, it is necessary to thoroughly comprehend their properties which have been developed and improved through the years. It is difficult to categorize hydrologic models precisely and various hydrologists may use different criteria. The reason is that while numerous models share common traits, the nature of the model is frequently the same. In this paper, the discussion starts with an introduction to ancient hydrology followed by the anthropogenic factors which directly or indirectly affect hydrological flows. Further the paper reviews hydrological modelling and the evolution of hydrologic models. The research aims to demonstrate classification of hydrologic models. The proper application of a model requires an in-depth understanding of it. In this research, eleven watershed hydrologic models were reviewed: ANN model, Unit Hydrograph, SCS-CN model, SVM model, HBV, TOPMODEL, PRMS, MIKESHE, VIC, HEC-HMS, MODFLOW and SWAT. SWAT model, one of the non-point source pollution models, is discussed along with its history and its major input variables. This literature also compiles and discusses applications of the SWAT model. SWAT was found to be promising models for long-term continuous simulations in agricultural watersheds. In agricultural watersheds, SWAT has been found to be the most assuring model for long-term continuous simulations.