Runoff coefficient estimation for various catchment surfaces

The definition of runoff coefficient is the portion of rainfall that turn into direct runoff throughout an occurrence, and it is a significant perception in engineering hydrology and is extensively applied for design and as a diagnostic variable to show runoff creation in catchments. Event runoff coefficients may also be applied in event‐based developed flood frequency models that measure flood frequencies from rainfall frequencies and are valuable for recognizing the flood frequency controls in a specific hydrologic or climatic regime. Only a few previous studies worked on hydrological systems and processes deeply at catchment scale. Also in many catchments because of lacking data sets, analysis of land use change and water management and risks causes uncertainty in predictions of hydrological processes can be decreased. This problem is more important for predicting hydrology of ungauged basins in developing countries. The purpose of this study is to review predicting hydrology of ungauged basins.