Our series of articles [1-4] named “Physical Processes in the Nature”, launched in 2014 have the aim to provide concrete help to teachers in integrated science education. In the series, we gather phenomena and processes that illustrate the intertwining and fundamentally unified view of physics, biology and geography. The first article concreted the soil physics, the second one the physical and chemical properties of water, the third the physics of oceans, seas and the fourth the physics of lakes. This article summarizes the physical characteristics of rivers.