Final answer:
The Karun River, Iran's longest river wholly within the country and its only navigable river, is a tributary of the Shatt al-Arab river. The Shatt al-Arab river, together with the Euphrates river, defines the Mesopotamian region and forms part of the border between Iran and Iraq. The region is historically important, and access to its water resources has been a cause for conflicts such as the Iran-Iraq War.
Step-by-step explanation:
The Karun River is a significant river in Iran, known for being the longest river wholly within the country and the only navigable river. This river is a tributary of the Shatt al-Arab river, which forms part of the border between Iran and Iraq. The Karun's confluence with the Shatt al-Arab river occurs near the border of Iraq, before it empties into the Persian Gulf. The larger Shatt al-Arab river is significant for its role in defining the Mesopotamian region, along with the Euphrates river.
Historically, this area has been contested ground due to its strategic location and the access it provides to powerful water resources. Particularly during the Iran-Iraq War of 1980-88, disagreement over the Shatt al-Arab waterway escalated into armed conflict.Iran, being largely a desert climate, has developed sophisticated means of water redistribution, including the use of qanats to channel water from higher elevations to urban areas. These methods of water management are an integral part of the country's geography.
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