Young Black Haired Girl Naked Outside On The Field

Although constrained by land mass and topology, the amount of arable land, both regionally and globally, fluctuates due to human and climatic factors such as irrigation, deforestation, desertification, terracing, landfill, and urban sprawl. Researchers study the impact of these changes on food production.
The most productive portion of arable land is that from sediments left by rivers and the sea in geological times. In modern times, rivers do not generally flood as often in areas employing flood control.