Dam or sea can be considered as a permanent base level of erosion because they are natural features that regulate the amount of erosion that can occur in a particular area. Dams control the flow of water in rivers, which can affect the erosion rates downstream. Similarly, the sea acts as a base level for erosion along coastlines, where the constant action of waves and tides can wear away the land. These natural features provide a constant and stable level of erosion that impacts the surrounding landscape.
