Diccionari de Llengües

                                               

                                                         LENGUAGE DICTIONARY

 Parts of the rivers 

high course

It is the first part of the river , usually located in the mountains. Water drops sharply. Erosion is very strong.
 Erosion in rivers animation Enlarge
Source : school-portal.co.uk
midcourse

The slope is less . The waters descend more slowly , dragging eroded materials . The river meanders may form , adapting to obstacles.

course under

It is the final part where the river ends its route . Usually it ends up in the sea , pelleting materials that have been washed away.

The mouth of the river can be of two types :

Delta: land consists of accumulated by the river in contact with the sea material.
Estuary : the place where the river comes   into contact with the sea , where the sea enters the mouth . It is subject to strong tides .

                                                                                                                 AMAZONA´S RIVER                      https://www.google.es/search?q=foto+rio+imprersionante&espv=2&biw=1280&bih=923&source=lnms&tbm=isch&sa=X&ved=0ahUKEwilv7uIrZvNAhXG1RoKHRwbDosQ_AUIBigB#tbm=isch&q=rio+amazonas&imgrc=hcubSEvNRCcQaM%3A