This review shows how cows are important agents of geomorphological change. On the uplands, heavy grazing compacts the soil, reduces infiltration, increases runoff, and increases erosion and sediment yield. However, light and moderate grazing have effects that are much less significant. In riparian zones, grazing decreases erosional resistance by reducing vegetation and exposing more vulnerable substrate. Trampling directly erodes banks, thus increasing turbulence and consequent erosion. Future studies should be framed within the hydroclimatological, edaphic, and geomorphological dimensions of the areas being studied so that controlling variables may be more readily isolated. Trimble and Mendel believe that both empirical studies and deterministic modelling can provide insights as to the effects of grazing on geomorphology.
The cow as a geomorphic agent-a critical review