تحليل اتجاهات الجفاف المناخي باستخدام مؤشر الجفاف الاستطلاعي(RDI) وأثرها في الغطاء النباتي في العراق

Abstract

By analyzing drought and its directions using the Drought Survey Index, it became evident that drought waves in Iraq are intensifying in both frequency and severity. The general trend analysis also indicated that the index (RDI) tends to decrease in its recorded values over time, which signifies an increase in the severity of drought conditions. Furthermore, a model developed to assess drought risks—based on the changes in severity and frequency of drought waves—revealed that the undulating region is more susceptible to drought risks compared to the rest of the study area over the past few decades. This is attributed to the rising frequency and severity of droughts, as well as the deepening of drought conditions, resulting from the northward shift of the rainfall line (300 mm) towards northern Iraq. Consequently, this region has entered a zone characterized by unreliable rainfall typical of semi-humid areas, which is one of the outcomes of global climate change, from which Iraq is not exempt. Additionally, an analysis of two models for the wet (1992-1993) and dry (2009-2010) seasons concerning the vegetation cover index demonstrated that dense and very dense vegetation is more adversely affected than other types of vegetation cover in the study area during periods of drought. This is due to reduced rainfall and increased evapotranspiration resulting from rising temperatures.