عنوان مقاله [English]
Estimation of spatial distribution of rainfall in different time scales is one of the basic steps in water resources studies. Problems in selection of proper methods for spatial variation of rainfall can produce error in input parameters of rainfall-runoff models in design or prediction stages. Also, reducing uncertainty in rainfall distribution is important in water budget studies. There are different methods for estimation of spatial distribution of rainfall based on raingage point data. Geostatistical methods are among such techniques. Geostatistical methods are favored in engineering studies since these methods consider spatial structure and location of data points. In this study, a number of methods were evaluated to estimate spatial distribution of monthly and annual rainfall in southwest of Iran. These methods consist of Thin Plate Smoothing Splines (TPSS), Weighted Moving Average (WMA) and Kriging. Cross validation technique was used for comparison of the methods. Results showed, although the TPSS method with power of 2 was marginally the most accurate method (with minimum MAE) in estimating annual rainfall but co-kriging method showed better consistency with topography of the study area. Analysis of variogram and error variance also demonstrated that generating missing data decreases accuracy of the interpolation.