APPLYING THE INVERSE DISTANCE WEIGHTING AND KRIGING METHODS OF THE SPATIAL INTERPOLATION ON THE MAPPING THE ANNUAL PRECIPITATION IN BOSNIA AND HERZEGOVINA

Two methods of the spatial interpolation [Inverse Distance Weighting (IDW) and the Kriging], often used in the Geographical Information System (GIS), have been applied on the mapping of the annual amount of precipitation in Bosnia and Herzegovina. For that purpose the monthly precipitation data obtained from meteorological network in the period 1960-2011. The validation of the analyzed data has been carried out by using 20-meter resolution Digital Elevation Model (DEM). The methods, which are suitable for the spatial interpolation for Bosnia and Herzegovina area, particularly for the orographic regions, were analyzed. First, the IDW linear interpolator was considered. However, in the mountain region, this method can give unrealistic results („Bulls Eyes“ effect). Namely, this effect leads to occurrence of the isohyets, which are closed around the meteorological station that is not acceptable in analysis of the pluviometric regime in the real relief. In contrast to this method the Kriging method is much more acceptable because of its (i) adaptability to the relief configuration, (ii) fast data processing and (iii) high precision in calculating the precipitation and corresponding climate indexes for the high resolution of the grid cell. An acceptable annual pluviometric model with the 50x50 m resolution has been obtained by the application of the Kriging method, which was applicable at the local spatial scale, particularly in the orographic regions. More precisely, the designed annual pluviometric model is characterized by the high precision in the areas with the pronounced relief dynamics, where the energetic classes are above 6th category.