Discussion of symposium on land erosion “Piping”

The present writers are familiar only with the Picacho and San Pedro areas, among those cited by the authors, and therefore limit discussion to the occurrence of earth cracks in these areas.

The existence of piping is not questioned, and the five conditions suggested by the authors are a justified explanation in the San Pedro area, for example. It is thought, however, that some of the phenomena described as piping are earth cracks whose origins are governed by factors other than those outlined. Once formed, certain earth cracks may facilitate the development of piping by providing ready access to downward and lateral movement of water.