Results of the snowmelt-runoff model in an international test

The World Meteorological Organization (WMO) recently conducted an international project on the Intercomparison of Models of Snowmelt Runoff. Eleven different snowmelt-runoff models were tested on six snowmelt-basin data sets. The data required for testing the snowmelt-runoff model (SRM) were obtained for four basins-the Dischma basin in Switzerland (43.3 sq km), the Dunajec River in Poland (680 sq km), the Durance River in France (2170 sq km), and the W-3 basin in the U.S.A. (8.42 sq km). Snow cover input data were obtained from aircraft orthophotographs (Dischma), satellite images (Dunajec and Durance), and snow course readings (W-3). SRM performance was evaluated by examination of hydrograph plots, the coefficient of determination of daily discharges (NTD), and the difference in observed and computed runoff volumes (PD). The performance of SRM during the snowmelt season can be summarized as follows: Dischma, n = 10, NTD = 0.84, PD = 3.3%; Dunajec, n =1, NTD = 0.76, PD = 5.1%; Durance, n = 5, NTD = 0.85, PD = 7.3%; and W-3, n =10, NTD = 0.80, PD = 8.2%.