Answer:
Baghdad was linked to important trade networks, like the Silk Road, and it had access to water resources.
Step-by-step explanation:
The Abbasid Caliphate established its capital in Baghdad in 761 AD, founded by the Caliph Al Mansur. The Abbasid Caliphate was a multicultural Islamic empire that replaced the Ummayyad Caliphate, in which Arabs were considered first-class citizens. In the new Caliphate all cultures, mainly Persians, were welcomed. The new capital was moved to Baghdad because this region presented strategical characteristics for trade and access to resources.
First, Baghdad was located in the crossroads of the Silk Road, a trade network that linked the Middle East, North Africa, and Europe with China, India, and Eastern Markets. For this reason, Baghdad became an important node of this trade network and thrived in prosperity and wealth very quickly.
Second, Baghdad was near important sources of water resources, like the rivers Tigris and Euphrates, which also provided Baghdad good weather.
Third, the fact that Baghdad was between the rivers Tigris and Euphrates gave it access to maritime trade networks and maritime military power that increased the control of its vast empire.
For all these reasons, Baghdad worked as a strategical capital to increase the economic resources and the strategical power of the Abbasid Caliphate.