Determination of run-off factor of the Tons Catchment using aerial photographs

Run-off is an important element of the hydrologic studies of any given basin. As such the estimation of the run-off factor of a catchment becomes imperative for determination of the total quantity of its surface run-off. The traditional ground survey methods of hydrologic studies of river basins are gradually getting replaced by more economical and reasonably accurate methods mostly based on aerial photographs. This paper deals with an experiment carried out on the Tons Catchment for determination of its run-off factor with the help of aerial photographs using the photo-interpretation and analysis techniques. The resultant values of the surface runoff have compared very well with the observed flow at Kisau gauging station. This indicates that a suitable methodology can be developed to estimate the discharge of the catchment of Indian rivers, where the run-off data is not available, with reasonable accuracy using the aerial photographs.