What is the term for the gradual loss of land over time due to natural forces?

The term for the gradual loss of land over time due to natural forces is erosion. Erosion occurs when soil and rock are worn away and transported by wind, water, and other natural agents. This process can happen at varying rates depending on environmental factors such as rainfall intensity, vegetation cover, and human activity. Erosion can lead to significant changes in the landscape, including the reduction of land available for use, loss of topsoil, and even the alteration of water courses.

In contrast, afforestation refers to the process of planting trees in a barren area to create a forest, which can actually help combat erosion. Degradation generally refers to the deterioration of the quality of land, water, or air, encompassing a broader range of issues that may include erosion but is not limited to it. Excavation involves the removal of earth to create space for construction and other purposes, which is a different process altogether. Therefore, erosion is the most accurate term for the loss of land due to natural forces over time.