Effect of Watershed Characteristics on a Rainfall Runoff Analysis and Hydrological Model Selection - A review

The rainfall-runoff analysis and modeling have been the subject of a large number of research activities and a range of types of models have been developed in the last few decades, to predict the runoff well in advance to avoid the huge amount of losses due to floods. However, all these research activities are focused on the result and accuracy of models and their comparative study. It often remains unclear which model is best under which conditions. It is necessary to select the appropriate rainfall-runoff model for the watershed area according to its physical/chemical/biological characteristics. In this paper, one of the significant characteristics of the watershed that is the size of the case study area is selected as a parameter to understand how it affects the selection of the model. To understand this, 42 research papers published between 2000 to 2019 have been reviewed and categorized according to the size of the watershed, climatic conditions, and type of models used for rainfall-runoff analysis. The result obtained indicates that for major research work, black box models or data-driven models have been used for the watershed of size ranging between 250 km2 to 10000 km2. Similarly, maximum work is carried out for medium size watershed areas.