How does colonisation become a theme in the poem Expelled?

The theme of colonisation emerges in the poem "Expelled" through imagery that parallels historical processes of colonisation: the protagonist becomes like an "explorer discovering territory" as she navigates an unknown landscape, "conquering the unknown and taking it as [her] own." Furthermore, as she travels the land becomes hers without resistance, implying it was previously unoccupied, much like many colonies were settled upon the false notion that the land did not belong to native inhabitants.