Why are rivers and fertile land so important that Columbus described them in such detail?

Explanation:

Between 1492 and 1504, Italian explorer Christopher Columbus led four Spanish-based transatlantic maritime expeditions to the Americas, a continental landmass which was virtually unknown to and outside of the Old World (Afro-Eurasia). These voyages to America led to the widespread knowledge of its existence. This breakthrough inaugurated the period known as the Age of Discovery, which saw the colonization of the Americas, a related biological exchange, and trans-Atlantic trade. These events, the effects and consequences of which persist to the present, are sometimes cited as the beginning of the modern era.

hawaii was the final state

the conditions that made the byzantine empire vulnerable to attacks by the muslin turks were the sack of constantinople by western crusaders, the conquests of the sultanate of rum, presence of rival kingdoms and finally the set up of fiefdoms at the empire which were owned by the ghazis (turkish warriors).