Tigris–Euphrates river system through the central plain and combine at Al-Qurnah to form the Shatt al-Arab and discharge into the Persian Gulf. The region has historical importance as part of the Fertile Crescent region, in which civilization is believed to have first emerged. The ecoregion is characterized by two large rivers, the Tigris and Euphrates. The rivers have several small tributaries which feed into the system from shallow freshwater lakes, swamps, and marshes, all surrounded by desert. The hydrology of these vast marshes is extremely important to the ecology of the entire upper Persian Gulf. Historically, the area is known as Mesopotamia. As
Shule River by two reservoirs, Changma and Shuangta. There are also more than three additional hydropower/diversion dams on the river. The entire flow of the Shule is diverted directly downstream of the mountains into a canal that runs north-northeast across the delta, supplying farms in the valley to the north. This water is eventually returned to the river, but irrigation usage has caused the river to dry up well before its historic terminus. It is surmised that a few thousand years ago, the region was cooler and wetter, and the river had significantly more flow than it does today. Shule River The