Spatial Interpolation of Rainfall in Iraq

Abstract

Several methodologies exist for spatial interpolation of climate and weather parameters, among them is the inverse distance weighting. In this paper, the Inverse Distance Weighting (IDW) method was used to estimate the rainfall distribution in Iraq. The relationship between interpolation accuracy and two critical parameters of IDW were evaluated: these were power and a radius of influence (search radius). A total of 24 rainfall stations and rainfall data between 2003 and 2013 were used in this paper. Real data, obtained from Iraqi Meteorological Organization and Seismology, are used for evaluation. The results showed that these parameters have a great effect on the produced rainfall maps. The maps are produced for p= 1.5 and p=2.0 and were having profound effect of smoothing. The results present samples of maps for months January, October, and December for the years 2004, 2012, and 2013 within the period of the data.