Abstract:
The assessment and forecasting of surface water yield using the pattern emerging from past flow observations is based on assumption of stationary time invariant stochastic process. In principle, it is a problem of water balance under effects of land use and management with given or forecasted input precipitation and evapotranspiration demand. The success or otherwise of long term forecasting would depend on the presence of persistence in concerned time series due to carry-
over effects of soil moisture, snow, groundwater or surface water. Prior know-
ledge of the meteorological conditions increases the accuracy and reliability of forecasts. Inspite of recent developments in numerical weather prediction, operational reliable method for use in hydrological forecasting is yet to be evolved.
