Human activities that may affect the flow of water through river systems include diversion of water from one river basin to another, creation of artificial reservoir storage, destruction of natural wetland storage, and land changes that alter rates of erosion, infiltration, overland flow, or evapotranspiration. The effects of these human actions influence not only long-term average flows, but the magnitude and frequency of droughts and floods and year-to-year and season-to-season flow variations. These effects, in turn, have a variety of direct effects on man, related to availability of reliable water supplies for in-stream and withdrawal uses and to magnitude and frequency of flood damages. They also affect geomorphic features resulting [...]
