I took the picture above at city Chongqing in China, which is located on the upstream of Yangtze River and southwest of China. The bridge in the picture is heading to a part of the city that resembles an island. It’s near the confluence of Yangtze river and Jialing river, one of the largest tributaries of Yangtze River. A little further east in the image is a wharf that separates two rivers in a shape of V. On the river surface in front of the wharf, one side is yellow and muddy Yangtze River water, the other side is jade-green Jialing River water. That obvious dividing line at the junction of water flow attracts many visitors.
At then, I just felt it’s a miracle and did not do any research to understand why this happens. Now I know this formation is partly because of a heavy rainfall in one upstream despite the dryness in that of the other. In essence, the color difference is caused by different water composition especially the distinct sediment and silt content in the two river. Thus, when the raining season come, these difference would highlight out.