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
Water politics in the Jordan River basin the salinity of the tributary Yarmouk River is also satisfactory, at 100 ppm, but the lower Jordan river becomes progressively more saline as it flows south. It reaches twenty-five percent salinity (250,000 ppm) where it flows in the Dead Sea, which is about seven times saltier than the ocean. As a resource for freshwater the Jordan River drainage system is vital for most of the population of Palestine, Israel and Jordan, and to a lesser extent in Lebanon and Syria who are able to use water from other national sources. (Although Syrian riparian rights to the Euphrates has been severely