Spatial and Temporal Analyses of Precipitation and Temperature in Iraq

Abstract

Historical climate observations show that Iraq, and the rest of the world, is passing through a dramatic change in precipitation and temperature for the last twenty decades. Temperature trends are increasing with extreme precipitation events causing flooding, heatwaves, and drought affecting millions of people and costing billions. This study is focusing on the trends, seasonal variability, and the relationship between precipitation and temperature in Iraq. The study includes two analyses, spatial and temporal. The spatial analysis is investigating the relationships between precipitation and four other parameters: ground elevation, temperature, latitude, and longitude. The purpose of this analysis is to see how well precipitation is correlated spatially to these climatological and topographical variables. Results show that there is a good relationship between precipitation and latitude, which represents the distance from the equator, with coefficients of determination, R2, of 0.907. Temperature and elevation have a weak spatial relationship with precipitation, especially in the western part of the country. The second analysis includes the temporal trends of precipitation and temperature. Temporal analysis of precipitation shows the extreme climate events by calculating the error of observed precipitation from the best fit curve of historical data. Finally, both spatial and temporal analyses of precipitation were validated using different periods of observed data. The first 50% of the data was used for calibration and the second 50% of the data for validation and verse versa. Results show that calibrated equations have similar coefficients of determination compared with the validation results. In general, the relationships between monthly precipitation and both seasonality change and temperature are weak with coefficients of determination, R2, of 0.697 and 0.6858 respectively.