Effect of Rainfall Quantity on the Frequency of Severe Dust Storm in Iraq

Abstract

The dust storms and their recurrence are common phenomena in Iraq because it suffers from the exploitation of mankind to the natural environment and to the deterioration of vegetation and soil which responsible to the exposure of the soil to wind erosion leading to dust phenomena. Rain is one of the most influential climatic elements in reducing and minimizing the impact of dust storms. The amount of rainfall in Iraq is relatively small, where most of the year is not rainy. This in turn increases the dryness of the soil and increases the formation of dust storms. In this research data of (visibility, wind speed and direction and total rain amount) from the Iraqi Meteorological Organization and Seismology were analyzed for nine stations spread across the country (Mosul, Kirkuk, Haditha, Baghdad, Rutba, Nukhayb, Najaf, Amara and Nasiriya) for the period from 2001 - 2017 to compare annually severe dust storms with rainy seasons. Drought seasons were also determined using the percent of normal rainfall (PN) method. It was found that there was an inverse relationship between rainfall and severe dust storms, (according to Pearson’s correlation coefficient) where it was noticed that the highest amount of rainfall was in Mosul station with a total of 5231.6mm during the study period with only 6 severe dust storms during the same period. In other hand the lowest amount of rainfall was in Nukhayb station 1304.6mm during the study period with 62 severe dust storms.