The study of those land-forms and processes that are a direct result of human activity, including accelerated erosion, channelized river channels (i.e. rivers made to flow along fixed, sometimes concrete-lined, channels), the melting of permafrost, and ground subsidence due to the extraction of water or minerals. Particular examples include the Norfolk Broads, England, which are essentially flooded peat quarries, and the Zuider Zee, whose damming has had a major impact on the coastal morphology of the Netherlands.