Tigris–Euphrates river system border. Since the 1960s and in the 1970s, when Turkey began the GAP project in earnest, water disputes have regularly occurred in addition to the associated dam's effects on the environment. In addition, Syrian and Iranian dam construction has also contributed to political tension within the basin, particularly during drought. The general climate of the region is subtropical, hot and arid. At the northern end of the Persian Gulf is the vast floodplain of the Euphrates, Tigris, and Karun Rivers, featuring huge permanent lakes, marshes, and forest. The aquatic vegetation includes reeds, rushes, and papyrus, which support numerous species. Areas
Khabur (Euphrates) it the "Aborrhas" (Ἀβόρρας), and Isidore of Charax called it the "Aburas" (Ἀβούρας). It was described as a large river of Mesopotamia which rose in Mons Masius, about from Nisibis, and flowed into the Euphrates at Circesium (Kerkesiah). Procopius speaks of it as a river of importance, and Ammianus states that Julian the Apostate crossed it “per navalem Aborae pontem.” Strabo describes it as near the town of Anthemusia. The river is fed by several smaller streams, the names of which are mentioned in the later classical writers. These are, the Scirtus (Procop. "de Aedif." 2.7), the Cordes (Procop. "de