Global Warming and Its Impact on the Change of the De Martonne Drought Index at the Sulaimaniyah Station

Abstract

The aim of the research is to apply the De Martonne equation to calculate the drought index and also to calculate the general index of the variables involved in the equation, which are temperature and precipitation, for the time period (1973-2021) over 48 years for the Sulaimaniyah station. The results showed that the recorded minimum and maximum temperatures and precipitation were variable from year to year with small differences. It was found that by applying the general trend after dividing the study periods into five periods, each covering ten years, the general trend for minimum temperatures was upward, with three periods showing positive rising trends and two periods showing negative decreasing trends. As for the maximum temperatures and precipitation, the trend was negative for the first and second periods, while the third, fourth, and fifth periods showed positive rising trends. The results of the De Martonne equation, after evaluating the study period into nine periods, each covering five years, indicated that most of the periods were within the humid region with a vegetation cover of trees, except for the period from (2005-2009), which was classified as a semi-arid region with a herbaceous vegetation cover, with the index value being 19.6.