A Physical Network of Rivers

Author: Jun Yamamoto

We visualize the physical and topological networks of the Tone River in the Kanto region of Japan, the second longest river in Japan that flows north of Tokyo. Treating the river network as a physical network, we observe the scale-free natures of river length and degree distributions and the correlation between river lengths and degrees. Line widths in the physical network, node sizes in the topological graph, and node colors in both are proportional to the logarithm of river lengths. Black dots represent the links (intersections of rivers). The data is taken from the website of the National Land Information Division, National Spatial Planning and Regional Policy Bureau, Ministry of Land, Infrastructure, Transport and Tourism of Japan.