Operational snowmelt runoff forecasting in the Spanish Pyrenees using the snowmelt runoff model

The snowmelt runoff model (SRM) is used to simulate and forecast the daily discharge of several basins of the Spanish Pyrenees. We describe a method for snow mapping using NOAA-AVHRR data and a procedure to estimate retrospectively the accumulated snow water equivalent volume with the SRM. A linear combination of NOAA channels 1 and 2 is used to obtain a snow cover image in which the product is the percentage of the snow-covered area in each pixel. Real-time snowmelt forecasts are generated with the SRM using area snow cover as an input variable. Even in basins with a total absence of historical discharge and meteorological data, the SRM provides an estimation of the daily snowmelt discharge. By integrating the forecasted streamflow over the recession streamflow, snowmelt volume is obtained as a function of time. This function converges asymptotically to the net stored volume of water equivalent of the snowpack. Plotting this integral as a function of time, it is possible to estimate for each basin both the melted snow water equivalent (SWE) and the SWE remaining in storage at any point in the snowmelt season Spanish hydropower companies are using results from the SRM to improve water resource management. Copyright (C) 2002 John Wiley Sons, Ltd.