Comparison of spatial interpolation methods of hydrological data on example of the Pripyat river basin (within Ukraine)

Abstract

The article considers four methods of spatial interpolation: method of inverse weighted distances (IDW), triangulation (TIN), Spline interpolation and Kriging. The Pripyat basin was chosen as the study area, and the regularities of the spatial distribution of hydrological characteristics across the territory were assessed. For this territory, maps of spatial distribution of the specific discharge by four chosen methods were created; the accuracy of the obtained results was assessed. Based on the results of the work it was determined that the IDW method with a distance coefficient P=2 gives better results for the generalization of hydrological data over the studied area. The next most reliable methods are Kriging, which shows small errors, and Spline, with smooth transitions. The least suitable among the studied methods is TIN method. To study boundaries and territories that are outside the boundaries defined by GIS based on input data, in this case – Pripyat basin, IDW method is recommended to use, while every other can be used to study the central part of the catchment, with different reliability for the boundary territories.