A river is the specific place that takes place. It is usually a synonym for the river bed, but the channel includes groundwater, rivers that circulate through the interior of the caves, and the infiltration. Common is that under the bed of a river, and sometimes with different course, there are streams marbling with even higher flow than the river itself. But here try, basically, the superficial part of the River, i.e. the bed. In the bed of the river there are four elements: the canal, the lower bed, greater deathbed and sporadic greater deathbed.