Seasonal and inter-annual variation of precipitation in Iraq over the period 1992-2010

Iraq suffers from severe droughts, which are an inherent feature of its changing climate conditions. The shortage of water has a negative impact on agricultural land and is associated with a high risk of desertification. Thus, the identification of wetness conditions over a multi-year period is a challenging issue. In this paper, monthly and annual precipitation figures from twenty weather stations in Iraq were analyzed in order to provide insight into the seasonal and inter-annual variation and temporal trends in precipitation over the period of 1992-2010. The non-parametric rank-based Mann-Kendall test was applied to detect trends in annual series and the Kendall-Theil robust line was used to quantify their magnitude. The Mann-Kendall test statistic shows negative values for all stations and this emphasizes a climate change trend toward scarcity in precipitation. Most of the stations show a high significance level of more than 95%, white at the stations of Amarah, Baghdad, and Salahadeen only a drying signal was detected. The rate of change for Iraq amounts to 3.5% of mean annual precipitation calculated for the years 1992-2010.