The researchers studied the Ong river basin in India to understand its hydrological processes using a model called SWAT. They used various data like elevation, soil type, land use, and climate to create 52 hydrologic response units. By calibrating the model with streamflow data, they found that it accurately predicted the river's behavior. The study identified three key parameters that affect water flow in the area, showing the importance of both surface and groundwater properties. The model's performance was considered satisfactory based on calibration and validation results.