<P> The Tigris--Euphrates Basin is shared by Turkey, Syria, Iraq, Iran and Kuwait . Many Tigris tributaries originate in Iran and a Tigris--Euphrates confluence forms part of the Kuwait--Iraq 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 . </P> <P> 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 around the Tigris and the Euphrates are very fertile . Marshy land is home to water birds, some stopping here while migrating, and some spending the winter in these marshes living off the lizards, snakes, frogs, and fish . Other animals found in these marshes are water buffalo, two endemic rodent species, antelopes and gazelles and small animals such as the jerboa and several other mammals . </P> <P> Iraq suffers from desertification and soil salination due in large part to thousands of years of agricultural activity . Water and plant life are sparse . Saddam Hussein's government water - control projects drained the inhabited marsh areas east of An Nasiriyah by drying up or diverting streams and rivers . Shi'a Muslims were displaced under the Ba'athist regime . The destruction of the natural habitat poses serious threats to the area's wildlife populations . There are also inadequate supplies of potable water . </P> <P> The marshlands were an extensive natural wetlands ecosystem which developed over thousands of years in the Tigris--Euphrates basin and once covered 15--20,000 square kilometers . According to the United Nations Environmental Program and the AMAR Charitable Foundation, between 84% and 90% of the marshes have been destroyed since the 1970s . In 1994, 60 percent of the wetlands were destroyed by Hussein's regime--drained to permit military access and greater political control of the native Marsh Arabs . Canals, dykes and dams were built routing the water of the Tigris and Euphrates Rivers around the marshes, instead of allowing water to move slowly through the marshland . After part of the Euphrates was dried up due to re-routing its water to the sea, a dam was built so water could not back up from the Tigris and sustain the former marshland . Some marshlands were burned and pipes buried underground helped to carry away water for quicker drying . </P>

Which river is longer the tigris and the euphrates