For all hydrologic analyses, a watershed constitutes the spatial unit, and all hydrologic problems are solved in the context of this spatial unit. There are number of indices, which can be defined to illustrate variability of hydrologic behavior such as rainfall, runoff, evaporation, infiltration, peak discharge, unit hydrograph, groundwater table and its fluctuation, movement to name but a few. An estimate of runoff volume from a drainage basin involves precipitation, infiltration, evaporation, transpiration, interception, depression storage, each of which is complex and can interact with the other variables to either enhance or reduce runoff. These variables are variously distributed within a drainage basin. The manner in which these variables interact in time and space makes a direct determination of runoff very difficult. Therefore we estimate runoff by using methods that reflects combined effect of the variables on an individual drainage basin. Because no two drainage basins are exactly alike, no two solutions can be exactly alike. The present chapter incorporates various methods used to estimate runoff in the Shivganga drainage basin. The results obtained by analyzing basin hydrological parameters such as rainfall, evaporation and infiltration have been presented in detail on the basis of field data and the data obtained from various government agencies and institutes.

Keywords : Discharge, Evaporation, Interception, Hydrology, Hydrograph, Runoff.