assessing of interpolation methods in order to snow water equivalent estimation

snow is one of the main components of hydrological cycle in most of mountainous basins. since collecting the snow data (e.g. snow water equivalent data) is very difficult and time consuming, some effort is necessary to develop methods to estimate spatially variation of snow depth distribution. in the present study, the at-site swe data of 14 stations located in the west of isfahan providence for the period 1989-2010 were spatialized applying four methods composing the kriging, the co-kriging, the radial basis functions (rbf) and the inverse distance weighting (idw). in order to reach this purpose, first, the normality of data was checked using the kolmogorov – smirnov test. the homogeneity, the stability and the trend of data were tested employing the semivariogram approach. then the appropriate data of each year was entered into the arcgis 9.3 to conduct the methods. finally, the best method for spatializing the swe data was selected based on the rmse values. the results showed that the rbf method provided the best results for most of the years. furthermore, it was found that the amount of swe reduced from the south and west to the north and east of the basin.