An evaluation of spatial interpolation methods for estimating rainfall and air temperature in Egypt

Abstract EN

GIS layers for climatic data, which were generated based on irregularly distributed points, are very important for many disciplines such as climatology, agriculture and hydrology.

This study aims to evaluate eight spatial interpolation techniques such as IDW, spline, and kriging, and to compare their performance in generating optimal spatial distributions of monthly mean maximum and minimum temperature and total rainfall from meteorological stations network located across Egypt.

Interpolation techniques were applied to monthly climatic normals over 40-year period for more than 40 spatially- representative observatories in Egypt covering different micro-climate conditions.

Different statistical accuracy measurements such as Willmott Statistical methods and index of Nash-Sutcliffe efficiency criterion were used to determine the best methods.

Results demonstrate that optimal temperature mapping was obtained using Kok, Kr, SWT interpolation methods.

The performance of LPI and Kok interpolation methods was better than that of other methods as they produced better outcomes of surfaces prediction for rainfall.